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Mesomyzon mengae Chang, Zhang & Miao, 2006 (Figs 2-4) HOLOTYPE. ��� IVPP (Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China) collection number V14719, a nearly complete adult specimen, without preservation of the tail (Chang et al. 2006: fig. 1a). REFERRED MATERIAL. ��� IVPP V14718 A, B (a metamorphosed individual), V14981 A, B, V15027 A, B, V15450.3, V15448 A, B, V15449. HORIZON AND LOCALITY. ��� Yixian Formation, Lower Cretaceous (c. 125 Ma) (Zhou 2014; Zhou & Wang 2017); Ningcheng, Inner Mongolia and Yongyin County, Hebei Province, China. AMENDED DIAGNOSIS. ��� A fossil lamprey with elongated and eelshaped body, body length 12 times the maximum body depth, 4 times the head length; first gill pouch posteroventral to otic capsule; prebranchial region long, twice the maximum head height and 1.3- 1.8 times the branchial length; oral papillae large and triangular (conical); oral fimbriae numerous, maximum number presumably no less than 80; circumoral teeth series incomplete and lacking the posterior section; supraoral lamina large and bicuspid; two dorsal fins widely separated, anterior dorsal fin long and commencing above 4 th gill pouch; ribbon-like preanal skin fold long and extending to anterior branchial region; anal fin fold present; 70-80 preanal muscular segments; preanal myomeres Z-shaped and caudal ones W-shaped; tail hypocercal. DESCRIPTION General appearance As described byChang et al. (2006), Mesomyzon has an eel-like body and lacks paired fins. The adult individuals described here are larger than the holotype (Table 1). They have a welldeveloped oral disc and a long prebranchial region. The new materials here show that the anterior dorsal fin is very long and the ventral midline of the trunk is fringed with a ribbonlike preanal skin fold. The tail is hypocercal (Fig. 2). Head The cranial cartilages are preserved in imprints in some specimens. Here we follow Hardisty & Potter (1981) and De Iluiis & Puler�� (2011) for the terminology of the cranial cartilages referred below. The main parts of the anterior and posterior dorsal cartilages, and the anterior lateral cartilage can be delineated (Figs 3 A-D; 4A-C). The anterior lateral cartilage is situated ventrolaterally to the front part of the anterior dorsal cartilage and is tapering in the ventral part. The anterior dorsal cartilage is wider in the hind part than in the front, whose lateral margin is flared backward into a posterolateral angle. The posterior limit of the anterior dorsal cartilage terminates at the level very close to the external narial opening. The posterior dorsal cartilage is wider than the anterior dorsal cartilage and overlaps the latter posteriorly as in living lampreys (Fig. 1B) (Hardisty & Potter 1981: fig. 4; Marinelli & Strenger, 1954: (figs 24, 51a). There is a joint occasionally preserved in the fossils along the dorsal edge of the snout region (some distance in front of the eyes) (Figs 3B, C; 4A) which might indicate the differentiation of the anterior dorsal and posterior cartilages. To the rear of the posterior dorsal cartilage there is a notable dark imprint which is nearly vertically arranged immediately in front of the eye (Figs 3A, B; 4A). This may represent the anterior pillar of the subocular arch (Figs 3B; 4A) to form the anterior part of the orbital cavity as in living lampreys (Johnels 1948: fig. 57; Hardisty & Potter 1981: fig. 4; Janvier 1993: fig. 4.4). The imprints of the styliform cartilage is preserved posteroventral to the otic capsule (Figs 3 A-D; 4A). It extends posteroventrally towards the pharynx as its counterpart in living forms (Hardisty & Potter 1981: fig. 4). It is linked to the velar skeleton by small muscles in modern lampreys (Janvier 1993). The structures of the naso-hypophysial complex is wellpreserved in IVPP V 15449 and V 15450.3, with the olfactory organ���s left side exposed in the former and the dorsal aspect in the latter (Figs 3 C-F; 4B, F). It is enclosed within the imprints of the nasal sac, which is located in the midline and just anterodorsally to the eyes and likely independent from the cranial cartilages. The olfactory organ is preserved in a way that it partly overlaps the naso-hypophysial atrium in IVPP V 15449 (Figs 3C, D; 4B). The preserved part of this organ bears eight folds in IVPP V 15449 (dorsolateral view) (Figs 3C, D; 4B) and six parallel and evenly arranged folds in IVPP V 15450.3 (dorsal view) (Figs 3E, F; 4F). The naso-hypophysial duct extends anterodorsally for a length that approximates that of the short axis of the eye to the naris, which is dorsally positioned without a depression surrounding itself as in living lampreys (Janvier 1974). The hypophysial pouch (tube) (Figs 3C, D; 4B), a blind-ending structure serving to pump water into and out of the naso-hypophysial atrium (Janvier 1974), extends posteroventrally from the bottom of the olfactory organtowards the pharynx, and bends downward abruptly when it approaches the branchial apparatus. It must have extended more posteriorly, as its rear is covered by the gill structures in IVPP V 15449. The region of the pineal organ cannot be clearly distinguished as it is blurred by a patch of dark matter above the olfactory organ. Brain and cranial nerves (IVPP V15450.3): The remnants of the brain are represented by a patch of coarse sediments in IVPP V 15450.3 (Figs 3E, F; 4F). Based on the position of the roots of some cranial nerves and their arrangement in living lamprey (Fig. 1C), the major divisions of the brain can be roughly recognized. The paired olfactory nerves can be roughly discerned, which contact anteriorly with the hind part of the nasal sac. The posterior part of the telencephalon is rounded and terminated at the level of the posterior rim of the eyes. After exiting from the braincase, the trigeminus ophthalmicus profundus (V 1) extends above the eyes and branches off to innervate the annular muscles of the oral disc. The buccal ramus of the facial nerve (VII.buc) exits below the eyes and extends anteriorly to be convergent with the V 1 toward the oral disc. The recurrent rami of the facial nerve are well preserved in situ, and originally surround the otic capsules. The labyrinth membrane cannot be detected in our materials. The glossophyngeus (IX) and vagus (X) nerves are also arranged in a pattern that is almost identical to that in living lampreys (Fig. 1C) (Marinelli & Strenger 1954: figs 51, 52). Oral disc The oral disc and other associated structures are detected based on the pattern in living lamprey (Fig. 1D). In larger individuals, the oral disc is well developed, with the anterior fieldwider than the lateral and posterior ones. In IVPP V 15449, where the oral disc is best preserved, the oral disc occupies 6.64% of the total body length. In the same specimen, the impressions of a dozen of oral fimbriae (right side) are preserved in the perimeter of the oral disc (Fig. 3C, D). They are small, rod-like, and so closely arranged that they form together a comb-like pattern. This morphology is reminiscent of the oral fimbriae in living lampreys (Renaud 2011) and the ridges along the periphery of the oral disc of fossil lamprey Priscomyzon (Miyashita et al. 2021) Based on the arrangement of these structures, and the proportion of the length with the fimbriae preserved, at least 80 oral fimbriae might be present around the oral disc in IVPP V 15449. The oral papillae are partly preserved in IVPP V 15027 and 15449 (larger individuals) (Figs 3 A-D; 4C). They fringe the outer rim of the oral disc. The papillae are fairly large in relative to the oral disc size and triangular in shape (possibly conical as in living lampreys when the animals were alive, Renaud 2011: 5, fig. 20). They are connected to each other at the base, so that they must have entirely surrounded the oral disc. Judging from their size and arrangement, there could be no more than 30 oral papillae in the material at hand. Annular cartilage This is the structure that supports the supraoral and infraoral laminae (Renaud 2011). The remains of the annular cartilage are seen in some specimens, which are demonstrated either as a horseshoe-like impression (smaller individuals) or a nearly complete circle (larger individuals) (Figs 3 A-F; 4A, C). When complete, its anterior part appears to be somehow broader than the posterior part. Interestingly, in the specimen (IVPP V 15450.3) with a horseshoe-like impression of the annular cartilage, no traces of the posterior part of the cartilage are discernable although the remainder of this cartilage (element) is very well-preserved. ���Teeth��� In all large adult individuals with the well-preserved impression of the oral disc and annular cartilage, some non-mineralized, presumably keratinous teeth are already in place, though being developed to a lesser extent than in extant lampreys (Marinelli & Strenger 1954; Renaud 2011). Although the arrangement of the keratinous teeth varies among living lampreys, e.g., Geotria australis Gray, 1851 has few teeth in the posterior field of the oral disc, Lampetra fluviatilis (Linnaeus, 1758) lacks anterior and posterior circumoral teeth (Potter & Hilliard 1987), as a whole they all have more teeth on the oral disc than Mesomyzon. In Mesomyzon, there are no teeth preserved on the anterior, lateral and posterior fields (see Hubbs & Potter 1971; Renaud 2011 and Fig. 1D for delineation) of the oral disc outside of the circumoral teeth. Given the good preservation of the circumoral teeth under the same taphonomic condition, teeth might be absent, or at least very weakly developed on those fields. The series of the circumoral teeth is incomplete, only the anterior and lateral rows are prominent. These triangular teeth are relatively loosely arranged and similar in size. The teeth on the supraoral lamina are strong and bicuspid (Figs 3A, B, E, F; 4A, C). Those on the infraoral lamina are occasionally seen, and are also roughly triangular in shape (Figs 3A, B; 4A, C). Although their detailed structure of the transversal and longitudinal lingual laminae can be recognized, some dark matter preserved roughly at the anterior end of the piston cartilage might suggest their presence (Figs 3 B-D; 4A). Lingual (piston) cartilage The piston cartilage is usually preserved as a slender longitudinal band extending along the ventral part of the pharynx from the mouth and posteriorly towards the branchial region (Fig. 3 B-D). In IVPP V 15035 A (Figs 3B; 4A), IVPP V 15449 (Fig. 3C, D), the anterior end of the piston cartilage, or apical cartilage, can be roughly recognized. It is continuous with the remaining part of this cartilage. This part is obviously darker in color than other part of the cartilage, possibly suggesting the fairly thick and complex structure (e.g., the apicalis cartilage) as in living lampreys (Marinelli & Strenger 1954: figs 19-21; Janvier 1993: fig. 4.4). Velar skeleton Immediately in front of the branchial apparatus, there is a prominent dark impression with an irregular profile (Figs 3B; 4A) which points to velar skeleton on the basis of the comparison to its homologue in extant lampreys (in Fig. 1A and Marinelli & Strenger 1954: figs 64, 65; Janvier 1993: fig. 4.4). More dorsally, there is a band-like impression extending anterodorsally toward the cranium, which is likely the imprinted styliform cartilage.This cartilage is linked to the velar skeleton by some muscles in modern lampreys (Janvier 1993). Branchial apparatus The distance between the eye and the branchial apparatus roughly equals the interval of four branchial openings. Seven gill pouches are seen, slightly slanting posteriorly, and of which the foremost one is triangular and much smaller than the remaining ones (Figs 2C; 3 A-D). The branchial basket is partially preserved in IVPP V 15027 A and 15449, where the impressions of the ventral part of branchial basket is well exposed. In the anteriormost part, some relics of the extra hyal arch can be detected (Figs 3C, D; 4D, E). More posteriorly, each of the branchial units shows a reversed Y-shaped profile in lateral view, which is connected ventrally with the longitudinal hypobranchial bar (Figs 3A, C, D; 4D, E). Based on the position relative to the external gill openings, this fork must be positioned below the hypotrematic bar, by comparison to the arrangement of gill basket in living lampreys (Fig. 1B) (Marinelli & Strenger 1954). This is different from the living lampreys in lacking the slanting rods above the junction of this bar and each extrabranchial arch as the attachment area of some external branchial constrictor muscles (Marinelli & Strenger 1954: figs 13, 14). Although we cannot say with certainty that this suggests difference in the configuration of the branchial muscles, the available information indeed reflects some structural variations of the gill-supporting architecture between Mesomyzon and olfactory pineal organ naso-hypophysial organ notochord atrium hypophysial pouch brain extant lampreys. We note that these muscle-supporting bars are not seen in lamprey larvae but exist later in adult forms (Hardisty 1981; Janvier 1993, 2008). The branchial basket is relatively well preserved in the Devonian lamprey Priscomyzon Gess, Coates & Rubidge, 2006 (Gess et al. 2006; Miyashita et al. 2021); however, its ventral part is also different from its analogue in Mesomyzon. There appears to be no bifurcation of the gill arch below the hypotrematic bar in Priscomyzon (Gess et al. 2006; Miyashista et al. 2021). More dorsally, the longitudinal hypotrematic bar, the epitrematic bar and the sub-chordal rod of the branchial basket are either blurred by the gill tissues or not observable in available fossil materials. The external openings of the branchial apparatus are arranged in a posteriorly slanting line (Figs 2C; 3B). Their posterior rims are usually more visible (darker) than the anterior rims, which might be resultant from the existence of the papillae in the posterior edge (Marinelli & Strenger 1954: figs 13-15, 37, 38, 40, 41). Relative to the eyes, the branchial apparatus is more posteriorly positioned in Mesomyzon than in its Paleozoic relatives, whose branchial region extends forward nearly below the eyes (Bardack & Zangerl 1968; Janvier & Lund 1983; Lund & Janvier 1986; Janvier 2008) or even anterior to the eyes (Miyashita et al. 2021). The majority of living lampreys have a slightly more anteriorly located branchial region than in Mesomyzon, except for quite a few parasitic species, i.e., Entosphenus minimus (Bond & Kan, 1973), Lampetra lanceolata Kux & Steiner, 1972, which display a similar postocular length (the distance between the eyes and the first gill opening) to Mesomyzon (Renaud 2011). The ratio of prebranchial length/ branchial length in Mesomyzon ranges from 1.4 to 1.8, a similar state as in Paleozoic lampreys (Bardack & Zangerl 1968; Janvier & Lund 1983; Lund & Janvier 1986; Gess et al. 2006; Janvier 2008). This ratio in six out of all 39 living lamprey species falls within this range or slightly exceeds it (see Appendices 1; 2). It is interesting that all these six species above except for Lethenteron alaskenses Vladykov & Kott, 1978 are parasitic (Renaud 2011). Among all living species, the non-parasitic species tend to have a smaller prebranchial length/ branchial length ratio than the parasitic ones (Renaud 2011). The prebranchial length was also assessed in another criterion. This region in Mesomyzon is no less than twice the maximal head depth. It is notably longer than that in Mayomyzon Bardack & Zangerl, 1968, Hardistella Janvier & Lund, 1983 and Pipiscius Bardack & Richardson, 1977 (Bardack & Zangerl 1968; Bardack & Richardson 1977; Janvier & Lund 1983; Janvier 2008). Priscomyzon Gess et al., 2006 displays a prebranchial length/maximal head depth ratio of c. 2, which actually results from the enlargement of the oral disc (Gess et al. 2006). This ratio in half of the living lampreys is smaller than that in Mesomyzon, whereas the remaining living species (21 out of 39 species) have a ratio approximating 2 or beyond (see Appendices 1; 2). Pericardinal cartilage The pericardial cartilage is connected to the rear of the branchial basket (Figs 3 A-F; 4D), and shows a profile of an equilateral triangle with little difference from that in living lampreys (Fig. 1A, B and Marinelli & Strenger 1954: figs 59, 60; Hardisty & Potter 1981). Intestine The accurate morphology of the intestine cannot be determined; however, its position can be traced by the arrangement of the detrital gobbets occasionally preserved in some large adult specimens. Judging from the detritus preserved immediately behind the last gill pouch (Fig. 3C, D), the intestine is arranged in a similar pattern as in living adult lampreys (Fig.1A and Marinelli & Strenger 1954). The preserved part of the detrital crumbs consists of coarse sand grains of variable sizes and their presence in the digestive tube possibly hints at the fossil lamprey���s habit of attaching on stones or moving stones with their oral disc for nesting (Hardisty 1979; Renaud 2011), or alternatively the habit of burying themselves in the substrate when the mucus secreted by the oral fimbriae trapped the sand and silt, just like the case in some living lampreys (Khidir & Renaud 2003; Renaud 2011). In IVPP V 15449, there is a mass of detritus preserved between the buccal funnel and the pharyngeal cavity, which might locate the mouth (Fig. 3C, D). The ending of the intestine, the cloaca (anus) is located at the level of the peak of the ���posterior dorsal fin���. The liver can be detected just behind the pericardial cartilage in several specimens (Fig. 3A, E, F). It shows a triangular profile and this part is always in a brightly red in color on the matrix (e.g., in IVPP V 15448 A), which might be related with the oxidized iron ion (of the blood) originally concentrated in the liver organ. This is a similar preservation pattern interpreted in several agnathan fossils (Janvier 1996; Newman & Trewin 2001). FINS Dorsal and caudal fins Here we hold the assumption proposed by Janvier (2008: 1051) that the so-called ���posterior dorsal fin��� in lampreys should represent the anterior part of the caudal epichordal lobe inserted on the markedly hypocercal tail and this issue will be referred to in the discussion section below. The anterior dorsal fin is so long that it extends anteriorly as far as to the level of the anterior edge of the fourth gill pouch. Its occupies 44%-48% of the total body length and the height occupies c. 50% of the maximal body depth. The fin changes little in height along its whole length, except that it is beveled smoothly at both ends. The anterior dorsal fin and the ���posterior dorsal fin��� are usually separated by a distance slightly smaller than the body depth in this position, except for one specimen (IVPP V 15448 A), where the base of the ���posterior dorsal fin��� extends anteriorly to touch the anterior dorsal fin and this connecting part lacks fin radials. This variation of ���posterior d, Published as part of Wu, Feixiang, Chang, Mee-Mann & Janvier, Philippe, 2021, A new look at the Cretaceous Lamprey Mesomyzon Chang, Zhang & Miao, 2006 from the Jehol Biota, pp. 1293-1307 in Geodiversitas 43 (23) on pages 1294-1300, DOI: 10.5252/geodiversitas2021v43a23, http://zenodo.org/record/5764679, {"references":["CHANG M. - M., ZHANG J. Y. & MIAO D. S. 2006. - A lamprey from the Cretaceous Jehol biota of China. Nature 441: 972 - 974. https: // doi. org / 10.1038 / nature 04730","ZHOU Z. H. 2014. - The Jehol Biota, an Early Cretaceous terrestrial Lagerstatte: new discoveries and implications. National Science Review 1: 543 - 599. https: // doi. org / 10.1093 / nsr / nwu 055","ZHOU Z. H. & WANG Y. 2017. - Vertebrate assemblages of the Jurassic Yanliao Biota and the Early Cretaceous Jehol Biota: Comparisons and implications. Paleoword 26: 241 - 252. https: // doi. org / 10.1016 / j. palwor. 2017.01.002","HARDISTY M. W. & POTTER I. C. 1981. - The skeleton, in The biology of lampreys. in HARDISTY M. W. & POTTER I. C. (eds), The Biology of Lampreys. Volume 3. Academic Press, New York: 118 - 124.","MARINELLI W. & STRENGER A. 1954. - Vergleichende Anatomie und Morphologie derWirbeltiere. I Lieferung. Petromyzon marinus (L). Deuticke, Wien.","JOHNELS A. G. 1948. - On the development and morphology of the skeleton of the head of Petromyzon. Acta Zoologica 29: 139 - 279. https: // doi. org / 10.1111 / j. 1463 - 6395.1948. tb 00030. x","JANVIER P. 1993. - Patterns of diversity in the skull of jawless fishes, in HANKEN J. & HALL B. K. (eds), The Skull. University of Chicago Press, Chicago: 131 - 188.","JANVIER P. 1974. - The structure of the naso-hypophysial complex and the mouth in fossil and extant cyclostomes, with remarks on amphiaspiforms. Zoologica Scripta, Stockholm 3: 193 - 200. https: // doi. org / 10.1111 / j. 1463 - 6409.1974. tb 00816. x","RENAUD C. B. 2011. - Lampreys of the World. An annotated and illustrated catalogue of lamprey species known to date. FAO Species Catalogue for Fishery Purposes no. 5. Food and Agriculture Organization of the United Nations, Rome: 109 p.","MIYASHITA T., GESS R. W., TIETJEN K. & COATES M. I. 2021. - Non-ammocoete larvae of Palaeozoic stem lampreys. Nature 591: 408 - 412. https: // doi. org / 10.1038 / s 41586 - 021 - 03305 - 9","POTTER I. C. & HILLIARD R. W. 1987. - A proposal for the functional and phylogenetic significance of differences in the dentition of lampreys (Agnatha: Petromyzontiformes). Journal of Zoology 212: 713 - 737. https: // doi. org / 10.1111 / j. 1469 - 7998.1987. tb 05966. x","HUBBS C. L. & POTTER I. C. 1971. - Distribution, phylogeny and taxonomy, in HARDISTY M. W. & POTTER I. C. (eds), The Biology of Lampreys. Volume 1. Academic Press, London: 1 - 65.","DE IULIIS G. & PULERA D. 2011. - The Dissection of Vertebrates: A Laboratory Manual. Academic Press. https: // doi. org / 10.1016 / C 2009 - 0 - 00124 - X","JANVIER P. 2008. - Early jawless vertebrates and cyclostome origins. Zoological Science 25: 1045 - 1056. https: // doi. org / 10.2108 / zsj. 25.1045","GESS R. W., COATES M. I. & RUBIDGE B. S. 2006. - A lamprey from the Devonian period of Southern Africa. Nature 443: 981 - 984. https: // doi. org / 10.1038 / nature 05150","BARDACK D. & ZANGERL R. 1968. - First fossil lamprey: a record from the Pennsylvanian of Illinois. Science 162: 1265 - 1267. https: // doi. org / 10.1126 / science. 162.3859.126","JANVIER P. & LUND R. 1983. - Hardistiella montanensis n. gen. et sp. (Petromyzontida) from the Lower Carboniferous of Montana, with remarks on the affinities of the lampreys. Journal of Vertebrate Paleontology 2: 407 - 413. https: // doi. org / 10.1080 / 027246 34.1983. 1001194","LUND R. & JANVIER P. 1986. - A second lamprey from the Lower Carboniferous (Namurian) of Bear Gulch, Montana (U. S. A.). Geobios 19: 647 - 652. https: // doi. org / 10.1016 / s 0016 - 6995 (86) 80061 - 4","BARDACK D. & RICHARDSON E. S. 1977. - New agnathous fishes from the Pennsylvanian of Illinois. Fieldiana (Geology) 33: 489 - 510. https: // doi. org / 10.5962 / bhl. title. 5167","HARDISTY M. W. 1979. - Biology of Cyclostomes. Chapman and Hall, London.","KHIDIR K. T. & RENAUD C. B. 2003. - Oral fimbriae and papillae in parasitic lampreys (Petromyzontiformes). Environmental Biology of Fishes 66: 271 - 278. https: // doi. org / 10.1023 / A: 1023961910547","JANVIER P. 1996. - Early Vertebrates. Clarendon Press, Oxford: 393 p.","NEWMAN M. J. & TREWIN N. H. 2001. - A new jawless vertebrate from the Middle Devonian of Scotland. Palaeontology 44: 43 - 51. https: // doi. org / 10.1111 / 1475 - 4983.00168","MIYASHITA T., COATES M. I., LARSON P. L. & MANNING P. L. 2019. - Hagfish from the Cretaceous Tethys Sea and a reconciliation of the morphological-molecular conflict in early vertebrate phylogeny. Proceedings of the National Academy of Sciences 116: 2146 - 2151. https: // doi. org / 10.1073 / pnas. 1814794116","VLADYKOV V. D. 1973. - A female sea lamprey (Petromyzon marinus) with a true anal fin, and the question of the presence of an anal fin in the Petromyzontidae. Canadian Journal of Zoology 51: 221 - 224. https: // doi. org / 10.1139 / z 73 - 032","SANSOM R. S., GABBOOTT S. A. & PURNELL M. A. 2010. - Decay of vertebrate characters in hagfish and lamprey (Cyclostomata) and the implications for the vertebrate fossil record. Proceedings of the Royal Society B 278: 1150 - 1157. https: // doi. org / 10.1098 / rspb. 2010.1641","SANSOM R. S., GABBOOTT S. A. & PURNELL M. A. 2013. - Atlas of vertebrate decay: a visual and taphonomic guide to fossil interpretation. Palaeontology 56: 457 - 474. https: // doi. org / 10.1111 / pala. 12037"]}

Lampreys, one of the remaining two living jawless vertebrates, carry great weight in the study of vertebrate evolution. They have a long history dating back to the Devonian but left a scarce fossil record. So far, only five unequivocal fossil lampreys have been described, of which four are Paleozoic. Mesomyzon Chang, Zhang & Miao, 2006, the only known Mesozoic lamprey bridging the Paleozoic and extant relatives, was originally considered similar in morphology and life history to modern forms. Although being repeatedly referred to in early vertebrate phylogeny, the morphology of Mesomyzon is far from adequately known. Based on extensive investigations on numerous new and well-preserved specimens, we present herein more details of the morphology of this fossil lamprey, thereby releasing a package of new information of the cranial nerves, some associated structures of the oral disc, and the naso-hypophysial complex, which are barely preserved in previously known fossil lampreys. Mesomyzon shows peculiarities in having an extremely long anterior dorsal fin and a ribbon-like preanal skin fold, and hence being restored in a distinct profile from the formerly claimed look. Additionally, it shares with some Southern Hemispheric species the widely separated dorsal fins, posteriorly positioned cloaca and enlarged oral papillae. In the light of these new data, the feeding ecology of Mesomyzon was tentatively discussed and this fossil lamprey was considered a likely blood feeder, judging from the reinforcement of the attachment and sensory structures on the periphery of the oral disc.

Unidentified opistognathid. Lissner and Dorsey (1986) observed from a manned submersible a jawfish they were unable to identify at Tanner��� Cortes Bank, southern California., Published as part of Love, Milton S., Bizzarro, Joseph J., Cornthwaite, Maria, Frable, Benjamin W. & Maslenikov, Katherine P., 2021, Checklist of marine and estuarine fishes from the Alaska-Yukon Border, Beaufort Sea, to Cabo San Lucas, Mexico, pp. 1-285 in Zootaxa 5053 (1) on page 150, DOI: 10.11646/zootaxa.5053.1.1, http://zenodo.org/record/5578008, {"references":["Lissner, A. L. & Dorsey, J. H. (1986) Deep-water biological assemblages of a hard-bottom bank-ridge complex of the southern California continental borderland. Bulletin of the Southern California Academy of Sciences, 85, 87 - 101."]}

Lampetra ayresii (G��nther, 1870). Western River Lamprey. To 34.6 cm (13.6 in) TL (Morgan et al. 2018). Tee Harbor, south-eastern Alaska (Scott and Crossman 1973) to San Francisco Bay, northern California (Vladykov and Follett 1958). Anadromous, found in estuaries and coastal marine waters for a few months in summer; depth: at sea, perhaps to 119 m (390 ft) (DFO) (taken in a midwater trawl; Maria Cornthwaite)., Published as part of Love, Milton S., Bizzarro, Joseph J., Cornthwaite, Maria, Frable, Benjamin W. & Maslenikov, Katherine P., 2021, Checklist of marine and estuarine fishes from the Alaska-Yukon Border, Beaufort Sea, to Cabo San Lucas, Mexico, pp. 1-285 in Zootaxa 5053 (1) on page 12, DOI: 10.11646/zootaxa.5053.1.1, http://zenodo.org/record/5578008, {"references":["Morgan, C. A., Zamon, J. E. & Bucher, C. A. (2018) Cruise Report, FV Frosti. NWFSC / NOAA, Cruise 18 - 02.","Scott, W. B. & Crossman, E. J. (1973) Freshwater fishes of Canada. Bulletin of the Fisheries Research Board of Canada, 184.","Vladykov, V. D. & Follett, W. I. (1958) Redescription of Lampetra ayresii (Gunther) of western North America, a species of lamprey (Petromyzontidae) distinct from Lampetra fluviatilus (Linnaeus) of Europe. Journal of the Fisheries Research Board of Canada, 15, 47 - 77."]}

Lethenteron camtschaticum (Tilesius, 1811). Arctic Lamprey. To 62.5 cm (24.6 in) TL (McPhail and Lindsey 1970). Almost circumpolar; White Sea and coasts of Barents Sea eastward off Siberia and Alaskan coasts to Beaufort Sea off Anderson River, Canada, and south through Chukchi and Bering Seas to Honshu, Japan, and Korean Peninsula in western Pacific Ocean; Kenai Peninsula, Gulf of Alaska in eastern Pacific; East Finnmark in eastern Atlantic (Mecklenburg et al. 2011). Depth: at sea to 50 m (164 ft) (Mecklenburg et al. 2002). Anadromous. Recently as Lampetra camtschatica (Tilesius, 1811). Provisionally considered to be a junior synonym of Lethenteron kessleri (Anikin, 1905) by Naseka and Renaud (2020)., Published as part of Love, Milton S., Bizzarro, Joseph J., Cornthwaite, Maria, Frable, Benjamin W. & Maslenikov, Katherine P., 2021, Checklist of marine and estuarine fishes from the Alaska-Yukon Border, Beaufort Sea, to Cabo San Lucas, Mexico, pp. 1-285 in Zootaxa 5053 (1) on page 12, DOI: 10.11646/zootaxa.5053.1.1, http://zenodo.org/record/5578008, {"references":["McPhail, J. D. & Lindsey, C. C. (1970) Freshwater fishes of northwestern Canada and Alaska. Bulletin of the Fisheries Research Board of Canada, 173.","Mecklenburg, C. W., Moller, P. R. & Steinke, D. (2011) Biodiversity of arctic marine fishes: taxonomy and zoogeography. Marine Biodiversity, 41, 109 - 140. https: // doi. org / 10.1007 / s 12526 - 010 - 0070 - z","Naseka, A. M. & Renaud, C. B. (2020) Morphology-based taxonomic re-assessment of the Arctic lamprey, Lethenteron camtschaticum (Tilesius, 1811) and taxonomic position of other members of the genus. Zookeys, 991, 1 - 67."]}

Entosphenus tridentatus (Richardson, 1837). Pacific Lamprey. To 85 cm (33.5 in) TL (Orlov et al. 2008b). Honshu (Orlov et al. 2008b), and Hokkaido, Japan (Nakabo in Nakabo 2002); eastern Chukchi Sea (Mecklenburg et al. 2002), and Bering Sea to Punta Canoas, northern Baja California (Miller and Lea 1972), and likely to Isla Clari��n, and Islas Revillagigedo, Mexico (Renaud 2008). Southernmost freshwater occurrence is currently in the Big Sur River, central California (Reid and Goodman 2016). Depth: at sea, near surface to 1,508 m (4,946 ft) (min.: Eschmeyer and Herald 1983; max.: Hoff and Britt 2003). Anadromous, may be found at sea, often far offshore, any time of the year. Previously as Lampetra tridentata (Richardson, 1836). The author of the species description is sometimes given as Gairdner, or Gairdner in Richardson, but authorship evidently is correct as Richardson, or Richardson (ex Gairdner) (Eschmeyer 1998 and online edition 8 November 2004)., Published as part of Love, Milton S., Bizzarro, Joseph J., Cornthwaite, Maria, Frable, Benjamin W. & Maslenikov, Katherine P., 2021, Checklist of marine and estuarine fishes from the Alaska-Yukon Border, Beaufort Sea, to Cabo San Lucas, Mexico, pp. 1-285 in Zootaxa 5053 (1) on page 12, DOI: 10.11646/zootaxa.5053.1.1, http://zenodo.org/record/5578008, {"references":["Orlov, A. M. & Tokranov, A. M. (2008 b) Specific features of distribution, some features of biology, and the dynamics of catches of smooth lumpsucker Aptocyclus ventricosus (Cyclopteridae) in waters of the Pacific Ocean off the Kuril Islands and Kamchatka. Journal of Ichthyology, 48, 81 - 95. https: // doi. org / 10.1134 / s 0032945208010086","Nakabo, T. (Ed.). (2002) Fishes of Japan with Pictorial Keys to the Species. Tokai University Press, Tokyo.","Miller, D. J. & Lea, R. N. (1972) Guide to the coastal marine fishes of California. California Department of Fish and Game Fish Bulletin, 157.","Renaud, C. B. (2008) Petromyzontidae, Entosphenus tridentatus: southern distribution record, Isla Clarion, Revillagigedo, Mexico. Check List, 4, 82 - 85. https: // doi. org / 10.15560 / 4.1.82","Reid, S. B. & Goodman, D. H. (2016) Pacific lamprey in coastal drainages of California: occupancy patterns and contraction of the southern range. Transactions of the American Fisheries Society, 145, 703 - 711. https: // doi. org / 10.1080 / 00028487.2016.1159615","Eschmeyer, W. N. & Herald, E. S. (1983) A Field Guide to Pacific Coast Fishes of North America from the Gulf of Alaska to Baja California. Houghton Mifflin, Boston.","Hoff, G. R. & Britt, L. L. (2003) The 2002 Eastern Bering Sea upper continental slope survey of groundfish and invertebrate resources. National Marine Fisheries Service Technical Memorandum, NMFS-AFSC- 141.","Eschmeyer, W. N. (Ed.). (1998) Catalog of Fishes. Volumes 1 and 2. Special Publication No. 1, Center for Biodiversity Research and Information. California Academy of Sciences, San Francisco."]}

Petromyzontidae Bonaparte 1831 Lampetra lanceolata Kux & Steiner, 1972 [E]―[EN], Turkish brook lamprey/ Türkiye dokuzgözlüsü/Black Sea watersheds of Anatolia (Kuru 2004; Geldiay & Balik 2007; Fricke et al. 2007; Kuru et al. 2014; Çiçek et al. 2015). Petromyzon marinus Linnaeus, 1758 [N]―[LC], Sea lamprey/Derebofa baligi/All coasts of Anatolian watersheds (Bilecenoglu et al. 2002, Fricke et al. 2007; Bilecenoglu et al. 2014; Çiçek et al. 2015)., Published as part of Çiçek, Erdogan, Sungur, Sevil & Fricke, Ronald, 2020, Freshwater lampreys and fishes of Turkey; a revised and updated annotated checklist 2020, pp. 241-270 in Zootaxa 4809 (2) on page 242, DOI: 10.11646/zootaxa.4809.2.2, http://zenodo.org/record/3934124, {"references":["Kuru, M. (2004) Recent systematic status of inland water fishes of Turkey. Journal of Education Faculty of Gazi, 24, 1 - 21.","Geldiay, R & Balik, S. (2007) Freshwater Fishes of Turkey. V. Edition, Ege University Press, Bornova, Izmir, 638 pp.","Fricke, R., Bilecenoglu, M. & Sari, H. M. (2007) Annotated checklist of fish and lamprey species (Gnathostomata and Petromyzontomorphi) of Turkey, including a Red List of threatened and declining species. Stuttgarter Beitrage zur Naturkunde, Serie A (Biologie), 706, 1 - 172.","Kuru, M., Yerli, S. V., Mangit, F., Unlu, E. & Alp, A. (2014) Fish Biodiversity in Inland Waters of Turkey. Journal of Academic Documents for Fisheries and Aquaculture, 1 (3), 93 - 120.","Cicek, E., Sungur-Birecikligil, S. & Fricke, R. (2015) Freshwater fishes of Turkey: A revised and updated annotated checklist. Biharean Biologist, 9 (2), 141 - 157.","Bilecenoglu, M., Taskavak, E., Mater, S. & Kaya, M. (2002) Checklist of the marine fishes of Turkey. Zootaxa, 113 (1), 1 - 194. https: // doi. org / 10.11646 / zootaxa. 113.1.1","Bilecenoglu, M., Kaya, M., Cihangir, B. & Cicek, E. (2014) An updated checklist of the marine fishes of Turkey. Turkish Journal of Zoology, 38, 901 - 929. https: // doi. org / 10.3906 / zoo- 1405 - 60"]}

The current status of the inland waters ichthyofauna of Turkey is revised, and an updated checklist of the freshwater fishes is presented. The latest checklist included all species listed in the available previous study that was published in 2015, which is now updated after a period of five years. We revised the validity of previously accepted species and added newly described and reported species in Turkey. Some previously erroneously reported species and not established alien fishes were excluded from this checklist. A total of 384 fish species belonging to 20 orders and 34 families have been reported in the inland waters of Turkey. Among these, 15 species (3.9%) are non-native and 208 species (54.2%) are considered as endemic to Turkey. A total of 119 species previously reported from Turkey have been excluded from Turkish ichthyofauna list, either in the present study or in previous studies.

Family † Nanpanaspididae Liu 1975, spelling in prevailing recent practice †Nanpanaspidae Liu 1975: 203 (family) † Nanpanaspis Liu 1965 [family name also seen as † Nanpanaspididae]

† Hardistiellidae Halstead 1993: 580 (family) † Hardistiella Janvier & Lund 1983 [name only, published after 1960, not available, Art. 13.1.1], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 15, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Halstead L. B. 1993. Agnatha. In: Benton M. J. (ed.) The Fossil Record 2: 573 - 581. Chapman and Hall, London. [Author also known as Tarlo L. B. H.]"]}

Family † Hanyangaspididae Pan & Liu 1975, spelling in prevailing recent practice †Hanyangaspidae Pan & Liu in Pan, Wang & Liu 1975: 147 (family) † Hanyangaspis Pan & Liu 1975 [family name also seen as † Hanyangaspididae]

Family † Jamoytiidae White 1946 † Jamoytiidae White 1946a: 96 (family) † Jamoytius White 1946, Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 19, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["White E. I. 1946 a. Jamoytius kerwoodi, a new Chordate from the Silurian of Lanarkshire. Geological Magazine 83 (2): 89 - 97. https: // doi. org / 10.1017 / S 0016756800082856"]}

Family † Xiushuiaspididae Pan & Wang 1983, spelling in prevailing recent practice †Xiushuiaspidae Pan & Wang 1983: 505 (family) † Xiushuiaspis Pan & Wang 1983 [family name also seen as † Xiushuiaspididae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 24, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Pan J. & Wang S. T. 1983. Xiushuiaspidae, a new family of Polybranchiaspiformes from Xiushui of Jiangxi province. Acta Palaeontologica Sinica 22 (5): 505 - 510. [In Chinese, with English summary.]"]}

Family † Superciliaspididae Scott & Wilson 2014 † Superciliaspididae Scott & Wilson 2014: 169 (family) † Superciliaspis Adrain & Wilson 1994, Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 23, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Scott B. R. & Wilson M. V. H. 2014. The Superciliaspididae, a new family of Early Devonian Osteostraci (jawless vertebrates) from northern Canada, with two new genera and three new species. Journal of Systematic Palaeontology 13 (3) [for 2015]: 167 - 187. [Published online 12 March 2014.] https: // doi. org / 10.1080 / 14772019.2013.863809"]}

Family † Scolenaspididae Afanassieva 1991 † Scolenaspididae Afanassieva 1991: 91 (family) † Scolenaspis Jarvik 1954, Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 23, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Afanassieva O. B. 1991. [The Osteostracans of the USSR (Agnatha)]. Transactions of the Palaeontological Institute (Academy of Sciences of the USSR) / Trudy Paleontologicheskogo Instituta, Akademia Nauk SSSR 248: 1 - 144. [In Russian, with English summary and contents. Author also seen as Afanas'eva.]"]}

Family † Eugaleaspididae Liu 1980, spelling in prevailing recent practice †Galeaspidae Liu 1965: 125, 130 (family) † Galeaspis Liu 1965 [type genus preoccupied by † Galeaspis Ivshin 1955 in Trilobita; invalid, Art. 39] †Liuaspidinidae [†Liuaspididae] Whitley 1976: 48 (family) † Liuaspis Whitley 1976 [type genus preoccupied by Liuaspis Borchsenius 1960 in Hemiptera; invalid, Art. 39] †Eugaleaspidae Liu 1980: 256 (family) † Eugaleaspis Liu 1980 [family name also seen as † Eugaleaspididae] †Tridensaspidae Liu 1986: 2, 9 (family) † Tridensaspis Liu 1986 [family name sometimes seen as †Tridensaspididae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 24, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Liu Y. - H. 1980. A nomenclatural note on Eugaleaspis for Galeaspis Liu, 1965; Eugaleaspidae for Galeaspidae Liu, 1965; Eugaleaspiformes for Galeaspiformes. Vertebrata PalAsiatica 18 (3): 256 - 257. [In Chinese, with English summary.]","Whitley G. P. 1976. More fish genera scrutinized. Australian Zoologist 19 (1): 45 - 50. Available from https: // biodiversitylibrary. org / page / 38968551 [accessed 29 Aug. 2018].","Liu S. - F. 1986. Fossil eugaleaspid from Guangxi. Vertebrata PalAsiatica 24 (1): 1 - 9. [In Chinese, with English summary.] Available from http: // www. ivpp. cas. cn / cbw / gjzdwxb / xbwzxz / 200903 / W 020090813373830261955. pdf [accessed 17 Jul. 2018]."]}

Family † Tremataspididae Woodward 1891, spelling in prevailing recent practice † Tremataspidae Woodward 1891a: 201 (family) † Tremataspis Schmidt 1866 [family name also seen as † Tremataspididae] †Odontotodontidae Jordan 1905: 506 (family) † Odontotodus Pander 1856 †“new family” Patten 1931: 672 (family) † Dartmuthia Patten 1931 [as a new family, but without the name, not available] † Dartmuthiidae Robertson 1935: 282 (family) † Dartmuthia Patten 1931 †Oeselaspidae Robertson 1935: 282 (family) † Oeselaspis Robertson 1935 [family name sometimes seen as † Oeselaspididae or as subfamily †Oeselaspidinae] †Didymaspidae Berg 1940: 357 (family) † Didymaspis Lankester 1867 [family name sometimes seen as † Didymaspididae or as subfamily †Didymaspidinae] †Sclerodidae Berg 1940: 357 (family) † Sclerodus Agassiz 1839 [corrected to † Sclerodontidae by Fowler 1947: 4, confirmed by Romer 1966: 347 and by Halstead 1993: 578] †Stigmolepidae Fowler 1947: 4 (family) † Stigmolepis Pander 1856 †Timanaspidinae Obruchev in Kossovoy & Obruchev 1962: 1149 (subfamily) † Timanaspis Obruchev 1962 [English translation: 108; also as a new family, † Timanaspididae, in Halstead 1993: 578] † Tannuaspididae Obruchev 1964a: 97 (family) † Tannuaspis Obruchev 1956 † Tyriaspididae Halstead 1993: 578 (family) † Tyriaspis Heintz 1967 [name only, published after 1960, not available, Art. 13.1.1] †Aestiaspidinae Afanassieva 1996: 567 (subfamily) † Aestiaspis Janvier & Lelièvre 1994 [English edition: 69], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 23, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Woodward A. S. 1891 a. Catalogue of the Fossil Fishes in the British Museum (Natural History) Part II. British Museum (Natural History), London. Available from https: // www. biodiversitylibrary. org / item / 125733 [accessed 17 Jul. 2018].","Jordan D. S. 1905. A Guide to the Study of Fishes Volume 2. Henry Holt and Company, New York. Available from https: // www. biodiversitylibrary. org / item / 118481 [accessed 17 Jul. 2018].","Pander C. H. 1856. Monographie der fossilen Fische des silurischen Systems der Russisch-Baltischen Gouvernements. Buchdruckerei der Kaiserlichen Akademie der Wissenschaften, St. Petersburg.","Patten W. 1931. New Ostracoderms from Oesel. Science 73 (1903): 671 - 673. Available from http: // www. jstor. org / stable / 1655241 [accessed 17 Jul. 2018].","Robertson G. M. 1935. The ostracoderm order Osteostraci. Science 82: 282 - 283. Available from http: // www. jstor. org / stable / 1661217 [accessed 17 Jul. 2018].","Berg L. S. 1940. Sistema ryboobraznykh i ryb, nyne zhivushchikh i iskopaemykh / Classification of fishes, both recent and fossil. Trudy Zoologicheskogo instituta Akademiia nauk Soiuza Sovetskikh Sotsialisticheskikh Respublik / Travaux de l'Institut Zoologique de l'Academie des Sciences de l'URSS 5 (2): 87 - 517. [In Russian, with complete English translation.] [Published after 23 July.]","Fowler H. W. 1947. New taxonomic names of fish-like vertebrates. Notulae Naturae (Philadelphia) (187): 1 - 16. [21 February]","Romer A. S. 1966. Vertebrate paleontology. Third edition. University of Chicago Press, Chicago / London.","Halstead L. B. 1993. Agnatha. In: Benton M. J. (ed.) The Fossil Record 2: 573 - 581. Chapman and Hall, London. [Author also known as Tarlo L. B. H.]","Kossovoy L. S. & Obruchev D. V. 1962. [The Lower Devonian in north Timan], Doklady Akademii Nauk SSSR / Comptes rendus de l'Academie des sciences de l'URSS (N. S.) 147 (5): 1147 - 1150. [In Russian, first author also seen as Kossovoi; English translation: 106 - 108.]","Obruchev D. V. 1964 a. [Branch Agnatha]. In: Obruchev D. V. (ed.) Osnovy paleontologii. Vol. XI Agnatha, Pisces: 34 - 116. Izdatel'stvo ' Nauka', Moscow. [In Russian, translated 1967, Fundamentals of Paleontology, Vol. XI. Agnatha, Pisces. Israel Program for Scientific Translations, Jerusalem.]","Afanassieva O. B. 1996. On the morphology and systematic position of tremataspid osteostracan Aestiaspis viitaensis (Agnatha). Paleontological Journal 30 (5): 566 - 570. [Also in Russian Paleontologicheskii Zhurnal 1996 (4): 68 - 72.]"]}

Family † Zenaspididae Stensiö 1958, spelling in prevailing recent practice † Zenaspididae Stensiö 1958: 215 (family) † Zenaspis Lankester 1870 [family name also seen as † Zenaspidae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 23, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Stensio E. 1958. Les cyclostomes fossils ou ostracodermes. In: Grasse P. P. (ed.) Traite de Zoologie Tome 13 Fascicule 1: 173 - 425. Masson and Cie, Paris."]}

Family † Euphaneropidae Woodward 1900 † Euphaneropidae Woodward 1900: 418 (family) † Euphanerops Woodward 1900 [family name sometimes seen as †Euphaneropsidae or †Euphaneropididae] † Lasaniidae Goodrich 1909: 202 (family) † Lasanius Traquair 1898, Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 19, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Woodward A. S. 1900. On a new Ostracoderm (Euphanerops longaevus) from the Upper Devonian of Scaumenac Bay, Province of Quebec, Canada. Annals and Magazine of Natural History (series 7) 5 (29): 416 - 419. [After 7 October and before December.] https: // doi. org / 10.1080 / 00222930008678308","Goodrich E. S. 1909. Vertebrata Craniata (First fascicle: cyclostomes and fishes). In: Lankester E. R. (ed.) A Treatise on Zoology Part IX: 1 - 518. Adam and Charles Black, London. Available from https: // www. biodiversitylibrary. org / item / 99568 [accessed 17 Jul. 2018]."]}

Family † Sanchaspididae Pan & Wang 1981, spelling in prevailing recent practice †Sanchaspidae Pan & Wang 1981: 114, 120 (family) † Sanchaspis Pan & Wang 1981 [family name also seen as † Sanchaspididae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 25, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Pan J. & Wang S. T. 1981. New discoveries of polybranchiaspids from Yunnan Province. Vertebrata PalAsiatica 19 (2): 113 - 121. [In Chinese, with English summary.] Available from http: // www. ivpp. cas. cn / cbw / gjzdwxb / xbwzxz / 200904 / W 020090813375229410576. pdf [accessed 17 Jul. 2018]."]}

Family † Duyunolepididae Pan & Wang 1982, spelling in prevailing recent practice †Duyunoaspidae Pan & Wang 1978: 301 (family) † Duyunaspis Pan & Wang 1978 [type genus preoccupied by † Duyunaspis Zhang & Qian 1977 in Trilobita; invalid, Art. 39] †Duyunolepidae Pan & Wang 1982: 370 (family) † Duyunolepis Pan & Wang 1982 [family name also seen as † Duyunolepididae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 25, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Pan J. & Wang S. T. 1982. A nomenclatural note on Duyunolepis for Duyunaspis P'an et Wang, 1978. Vertebrata PalAsiatica 20 (4): 370.","Pan J. & Wang S. T. 1978. [Devonian Agnatha and Pisces of South China]. In: Symposium on the Devonian System of South China 1974, Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences: 298 - 333. Geological Publishing House, Beijing. [In Chinese.]"]}

Family † Ateleaspididae Traquair 1900, spelling in prevailing recent practice † Ateleaspidae Traquair 1900: 834 (family) † Ateleaspis Traquair 1900 [family name also seen as † Ateleaspididae or †Ateleasididae] †Hemicyclaspinae Heintz 1940: 98 (subfamily) † Hemicyclaspis Lankester 1870 [family name also seen as †Hemicyclaspididae] †Hirellidae Heintz 1949: 321 (family) † Hirella Cossmann 1920 †Aceraspidae Stensiö 1958: 216 (family) † Aceraspis Kiaer 1911 [family name sometimes seen as †Aceraspididae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 22, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Traquair R. H. 1900. Report on fossil fishes collected by the Geological Survey of Scotland in the Silurian rocks of the south of Scotland. Transactions of the Royal Society of Edinburgh 39 (3): 827 - 864. https: // doi. org / 10.1017 / S 0080456800035237","Heintz A. 1940. Cephalaspida from Downtonian of Norway. Skrifter Utgitt av det Norske Videnskaps- Akademi i Oslo. Matematisk-Naturvidenskapelig Klasse 1939 (5): 1 - 119.","Heintz A. 1949. Cephalaspider fra Ringerike. Naturen 73: 321 - 340. [In Norwegian.]","Stensio E. 1958. Les cyclostomes fossils ou ostracodermes. In: Grasse P. P. (ed.) Traite de Zoologie Tome 13 Fascicule 1: 173 - 425. Masson and Cie, Paris."]}

Family † Polybranchiaspididae Liu 1965, spelling in prevailing recent practice †Polybranchiaspidae Liu 1965: 128, 133 (family) † Polybranchiaspis Liu 1965 [family name also seen as † Polybranchiaspididae] †Cyclodiscaspidae Liu 1975: 211 (family) † Cyclodiscaspis Liu 1975 [family name sometimes seen as †Cyclodiscaspididae]

Family † Boreaspididae Berg 1955, spelling in prevailing recent practice †Boreaspidae Berg 1955: 17 (family) † Boreaspis Stensiö 1927 [corrected to † Boreaspididae by Stensiö 1958: 213] †Hoelaspididae Stensiö 1958: 214 (family) † Hoelaspis Stensiö 1927, Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 24, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Berg L. S. 1955. Sistema ryboobraznykh i ryb, nyne zhivushchikh i isokopaemykh. 2 - e izdanie [Classification of fishes and fish-like animals, living and fossil, 2 nd edition]. Trudy Zoologicheskogo Instituta Akademiia nauk Soiuza Sovetskikh Sotsialisticheskikh Respublik / Travaux de l'Institut zoologique de l'Academie des Sciences de l'URSS] 20: 1 - 286. [In Russian, German translation 1958: System der rezenten and fossilen Fischartigen und Fische. Deutscher Verlag der Wissenschaften, Berlin; citation to the ' German page numbers'.]","Stensio E. 1958. Les cyclostomes fossils ou ostracodermes. In: Grasse P. P. (ed.) Traite de Zoologie Tome 13 Fascicule 1: 173 - 425. Masson and Cie, Paris."]}

Family † Huananaspididae Liu 1973, spelling in prevailing recent practice †Huananaspidae Liu 1973: 133 (family) † Huananaspis Liu 1973 [family name also seen as † Huananaspididae] †Lungmenshanaspididae Pan 1992: 45 (family) † Lungmenshanaspis Pan & Wang 1975 †Macrothyraspididae Pan 1992: 49 (family) † Macrothyraspis Pan 1992 † Qingmenaspididae Halstead 1993: 580 (family) † Qingmenaspis Pan & Wang 1981 [name only, published after 1960, not available, Art. 13.1.1]

Family † Endeiolepididae Stensiö 1939, spelling in prevailing recent practice †Endeiolepidae Stensiö 1939: 18 (family) † Endeiolepis Stensiö 1939 [family name also seen as † Endeiolepididae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 19, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Stensio E. 1939. A new anaspid from the Upper Devonian of Scaumenac Bay in Canada, with remarks on the other anaspids. Kungliga Svenska Vetenskapsakademiens Handlingar (series 3) 18 (1): 1 - 25."]}

Family † Sanqiaspididae Liu 1975, spelling in prevailing recent practice †Sanqiaspidae Liu 1975: 211 (family) † Sanqiaspis Liu 1975 [family name also seen as † Sanqiaspididae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 25, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Liu Y. - H. 1975. Lower Devonian agnathans of Yunnan and Sichuan. Vertebrata PalAsiatica 13 (4): 202 - 216. [In Chinese, with English summary.] Available from http: // www. ivpp. cas. cn / cbw / gjzdwxb / xbwzxz / 200905 / W 020090813377232796719. pdf [accessed 17 Jul. 2018]."]}

Family †Caproberycidae Patterson 1967 †Caproberycinae Patterson 1967: 88 (subfamily) † Caproberyx Regan 1911 †Alloberycinae Gayet 1982a: 28 (subfamily) † Alloberyx Gaudant 1969 † Stichocentridae Gayet 1982a: 32 (family) † Stichocentrus Patterson 1967 [name only, published after 1960, not available, Art. 13.1.1] † Stichocentridae Gayet 1982b: 99 (family) † Stichocentrus Patterson 1967, Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 74, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Patterson C. 1967. New Cretaceous berycoid fishes from the Lebanon. Bulletin of the British Museum (Natural History), Geology 14 (3): 67 - 109. Available from https: // www. biodiversitylibrary. org / page / 36368748 [accessed 17 Jul. 2018].","Regan C. T. 1911. The anatomy and classification of the teleostean fishes of the orders Berycomorphi and Xenoberyces. Annals and Magazine of Natural History (series 8) 7 (37): 1 - 9. https: // doi. org / 10.1080 / 00222931108692901","Gayet M. 1982 a. Essai de definition des relations phylogenetiques des Holocentroidea nov. et des Trachichthyoidea nov. (Pisces, Acanthopterygii, Beryciformes). Bulletin du Museum national d'histoire naturelle, Section C, Sciences de la Terre, paleontologie, geologie, mineralogie (serie 4) 4 (1 - 2): 21 - 41. Available from http: // bibliotheques. mnhn. fr / EXPLOITATION / infodoc / ged / viewportalpublished. ashx? eid = IFD _ FICJOINT _ BMCTE _ S 004 _ 1982 _ T 004 _ N 001 _ 1 [accessed 16 Sep. 2018].","Gayet M. 1982 b. Etude anatomique et systematique des acanthopterygiens du Senonien de Sahel-Alma (Liban). Palaeontographia Italica 72: 98 - 136."]}

Family † Dayongaspididae Pan & Zeng 1985, spelling in prevailing recent practice †Dayongaspidae Pan & Zeng 1985: 207, 212 (family) † Dayongaspis Pan & Zeng 1985 [family name also seen as † Dayongaspididae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 24, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Pan J. & Zeng X. - Y. 1985. Dayongaspidae, a new family of Polybranchiaspiformes (Agnatha) from Early Silurian of Hunan, China. Vertebrata PalAsiatica 23 (3): 207 - 213. [In Chinese, with English summary.] Available from http: // www. ivpp. cas. cn / cbw / gjzdwxb / xbwzxz / 200903 / W 020090813373989382150. pdf [accessed 17 Jul. 2018]."]}

Family † Kiaeraspididae Stensiö 1932, spelling in prevailing recent practice †Kiaeraspinae Stensiö 1932b: 75 (subfamily) † Kiaeraspis Stensiö 1927 [family name also seen as † Kiaeraspididae] † Nectaspididae Stensiö 1958: 220 (family) † Nectaspis Wängsjö 1952 [changed to †Nectaspidae by Fowler 1965b: 348] † Axinaspididae Janvier 1981: 115 (family) † Axinaspis Wängsjö 1952 †Acrotomaspididae Janvier 1981: 115 (family) † Acrotomaspis Wängsjö 1952 [also as new subfamily †Acrotomaspidinae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on pages 23-24, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Stensio E. 1932 b. The Cephalaspids of Great Britain. British Museum (Natural History), London. https: // doi. org / 10.5962 / bhl. title. 118830","Stensio E. 1958. Les cyclostomes fossils ou ostracodermes. In: Grasse P. P. (ed.) Traite de Zoologie Tome 13 Fascicule 1: 173 - 425. Masson and Cie, Paris.","Wangsjo G. 1952. The Downtonian and Devonian vertebrates of Spitsbergen, IX. Morphologic and systematic studies of the Spitsbergen Cephalaspids. A. Text, B. Plates. Norsk Polarinstitutt Skrifter (97): 1 - 653. Available from http: // hdl. handle. net / 11250 / 173537 [accessed 27 Jul. 2018].","Fowler H. W. 1965 b. A Catalog of World Fishes [Part III]. Quarterly Journal of the Taiwan Museum (Taipei) 18 (3 - 4): 341 - 397.","Janvier Ph. 1981. Norselaspis glacialis n. g., n. sp. et les relations phylogenetiques entre les Kiaeraspidiens (Osteostraci) du Devonien inferieur du Spitsberg. Palaeovertebrata 11 (2 - 3): 19 - 131. Available from http: // palaeovertebrata. com / Articles / sendFile / 89 / published _ article [accessed 17 Jul. 2018]."]}

Family † Mayomyzontidae Bardack & Zangerl 1971 † Mayomyzontidae Bardack & Zangerl 1971: 80 (family) † Mayomyzon Bardack & Zangerl 1968 [family name sometimes seen as † Mayomyzonidae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 15, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Bardack D. & Zangerl R. 1971. Lampreys in the fossil record. In: Hardisty M. W. & Potter I. C. (eds) The Biology of Lampreys Volume 1: 67 - 84. Academic Press, London."]}

Family † Tesseraspididae Berg 1955, spelling in prevailing recent practice † Tesseraspidae Berg 1955: 25 (family) † Tesseraspis Wills 1935 [family name also seen as † Tesseraspididae] † Natlaspididae Halstead 1993: 575 (family) † Natlaspis Dineley & Loeffler, 1976 [name only, published after 1960, not available, Art. 13.1.1], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 16, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Berg L. S. 1955. Sistema ryboobraznykh i ryb, nyne zhivushchikh i isokopaemykh. 2 - e izdanie [Classification of fishes and fish-like animals, living and fossil, 2 nd edition]. Trudy Zoologicheskogo Instituta Akademiia nauk Soiuza Sovetskikh Sotsialisticheskikh Respublik / Travaux de l'Institut zoologique de l'Academie des Sciences de l'URSS] 20: 1 - 286. [In Russian, German translation 1958: System der rezenten and fossilen Fischartigen und Fische. Deutscher Verlag der Wissenschaften, Berlin; citation to the ' German page numbers'.]","Halstead L. B. 1993. Agnatha. In: Benton M. J. (ed.) The Fossil Record 2: 573 - 581. Chapman and Hall, London. [Author also known as Tarlo L. B. H.]","Dineley D. L. & Loeffler E. J. 1976. Ostracoderm Faunas of the Delorme and Associated Siluro-Devonian Formations, North West Territories, Canada. Special Papers in Palaeontology 18, The Palaeontological Association, London."]}

Family † Cephalaspididae Agassiz 1844, spelling in prevailing recent practice †Cephalaspides Agassiz 1844 Tome II pt. 1: 308 (family) † Cephalaspis Agassiz 1835 [family name sometimes seen as †Céphalaspides; latinized to †Cephalaspidini by Bonaparte 1846: 4 (subfamily), latinized to † Cephalaspidae by Owen 1846: 50, Huxley 1861: 38 and Günther 1880: 353, latinized to †Cephalaspides by Giebel 1846: 64 and Giebel 1847: 261, latinized to †Cephalaspida by Asmuss 1856: 10; considered valid with this authorship by Müller 1846: 122, 151, by M’Coy 1848: 6, by Bronn 1849: 656, by Quenstedt 1852: 231, by M’Coy 1855: 598, by Pander 1856: 43, by Bleeker 1859: XI, by Denison 1951: 188 and by Halstead 1993: 578 Art. 11.7.2; not the order Cephalaspidea Fischer 1883 in Mollusca], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on pages 22-23, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Bonaparte C. L. 1846. Catalogo metodico dei pesci europei. Atti della Settima Adunanza degli Scienziati Italiani, Napoli, Part 2: 1 - 95. [Including Specchio generale del sistema ittiologico p. 3 - 9; also issued as separate, Napoli 1846.] https: // doi. org / 10.5962 / bhl. title. 59507","Owen R. 1846. Lectures on the Comparative Anatomy and Physiology of the Vertebrate Animals delivered at the Royal College of Surgeons of England 1844 and 1846. Part I. Fishes. Longman, Brown, Green and Longmans, London. https: // doi. org / 10.5962 / bhl. title. 113850","Huxley T. H. 1861. Preliminary essay upon the systematic arrangement of the fishes of the Devonian epoch. Memoirs of the Geological Survey of the United Kingdom (figures and descriptions illustrative of British organic remains) Decade X: 1 - 49. Available from https: // biodiversitylibrary. org / page / 45186111 [accessed 17 Jul. 2018].","Gunther A. 1880. An Introduction to the Study of Fishes. Adam and Charles Black, Edinburgh. https: // doi. org / 10.5962 / bhl. title. 109739","Giebel C. G. 1846. Palaozoologie, Entwurf einer systematischen Darstellung der Fauna der Vorwelt. Nulandt'sche Buchandlung, Merseburg. https: // doi. org / 10.5962 / bhl. title. 39515","Giebel C. G. 1847. Fauna der Vorwelt mit steter Berucksichtigung der lebenden Thiere. Band I Wirbelthiere Vierte Klasse Pisces. Brockhaus, Leipzig. Available from https: // www. biodiversitylibrary. org / item / 74314 [accessed 17 Jul. 2018].","Asmuss H. 1856. Das vollkommenste Hautskelett der bisher bekannten Thierreihe, an fossilen Fischen des alten rothen Sandsteins aufgefunden und aus ihren Resten erlautert. Abhandlung zur Erlangung der Magisterwurde. Schunmanns Wittwe & Mattiesen, Dorpat.","Muller J. 1846. Uber den Bau und die Grenzen der Ganoiden und uber das naturliche System der Fische. Abhandlungen der Koniglichen Akademie der Wissenschaften zu Berlin [Aus dem Jahre 1844]: 117 - 216. Available from https: // biodiversitylibrary. org / page / 30226042 [accessed 28 Aug. 2018].","M'Coy F. 1848. On some new fossil fish of the Carboniferous Period. Annals and Magazine of Natural History (series 2) 2 (7): 1 - 10. https: // doi. org / 10.1080 / 03745485809496133","Bronn H. G. 1849. Index palaeontologicus, Zweite Abtheilung B Enumerator palaeontologicus. Schweizerbart, Stuttgart: 635 - 682. Available from https: // www. biodiversitylibrary. org / item / 182180 [accessed 17 Jul. 2018].","Quenstedt F. A. 1852. Handbuch der Petrefaktenkunde. Laupp'sche Buchhandlung, Tubingen. https: // doi. org / 10.5962 / bhl. title. 15107","Pander C. H. 1856. Monographie der fossilen Fische des silurischen Systems der Russisch-Baltischen Gouvernements. Buchdruckerei der Kaiserlichen Akademie der Wissenschaften, St. Petersburg.","Bleeker P. 1859. Enumeratio specierum piscium hucusque in Archipelago indico observatarum, adjectis habitationibus citationibusque, ubi descriptiones earum recentiores reperiuntur, nec non speciebus Musei Bleekeriani Bengalensibus, Japonicis, Capensibus Tasmanicisque. Acta Societatis Regiae Scientiarum Indo-Neerlandicae [Verhandelingen der Natuurkundige Vereeniging in Nederlandsch Indie] 6. Natuurkundige Vereeniging in Nederlandsch Indie, Batavia. Available from https: // biodiversitylibrary. org / page / 47271149 [accessed 25 Sep. 2018].","Denison R. H. 1951. Evolution and classification of the Osteostraci. Fieldiana, Geology 11 (3 - 4): 156 - 196. https: // doi. org / 10.5962 / bhl. title. 3286","Halstead L. B. 1993. Agnatha. In: Benton M. J. (ed.) The Fossil Record 2: 573 - 581. Chapman and Hall, London. [Author also known as Tarlo L. B. H.]"]}

Family † Procephalaspididae Stensiö 1958 † Procephalaspididae Stensiö 1958: 215 (family) † Procephalaspis Denison 1951, Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 23, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Stensio E. 1958. Les cyclostomes fossils ou ostracodermes. In: Grasse P. P. (ed.) Traite de Zoologie Tome 13 Fascicule 1: 173 - 425. Masson and Cie, Paris.","Denison R. H. 1951. Evolution and classification of the Osteostraci. Fieldiana, Geology 11 (3 - 4): 156 - 196. https: // doi. org / 10.5962 / bhl. title. 3286"]}

† Pipisciidae Halstead 1993: 580 (family) † Pipiscius Bardack & Richardson 1977 [name only, published after 1960, not available, Art. 13.1.1], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 15, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Halstead L. B. 1993. Agnatha. In: Benton M. J. (ed.) The Fossil Record 2: 573 - 581. Chapman and Hall, London. [Author also known as Tarlo L. B. H.]"]}

Family † Birkeniidae Traquair 1900 † Birkeniidae Traquair 1900: 837 (family) † Birkenia Traquair 1898, Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 19, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Traquair R. H. 1900. Report on fossil fishes collected by the Geological Survey of Scotland in the Silurian rocks of the south of Scotland. Transactions of the Royal Society of Edinburgh 39 (3): 827 - 864. https: // doi. org / 10.1017 / S 0080456800035237"]}

Family † Benneviaspididae Denison 1951, spelling in prevailing recent practice †Benneviaspinae Denison 1951: 190 (subfamily) † Benneviaspis Stensiö 1927 [family name also seen as † Benneviaspididae], Published as part of Laan, Richard Van Der, 2018, Family-group names of fossil fishes, pp. 1-167 in European Journal of Taxonomy 466 on page 24, DOI: 10.5852/ejt.2018.466, http://zenodo.org/record/5557557, {"references":["Denison R. H. 1951. Evolution and classification of the Osteostraci. Fieldiana, Geology 11 (3 - 4): 156 - 196. https: // doi. org / 10.5962 / bhl. title. 3286"]}

Lampetra soljani, new species (Figs. 3–7) Holotype. ZFMK-ICH 103666, 109 mm TL; Bosnia and Herzegovina: side-arm of Neretva River east of Čapljina, 43.106458 17.709536; P. Tutman, 16–17 Jan. 2015. Paratypes. FSJF 3650, 12, 105– 126 mm TL; same data as holotype.—FSJF 1037, 1, 111.3 mm TL; Bosnia and Herzegovina: lowermost stream Bregava north of Klepci, 43.052808 17.698089.— FSJF 2184, 1, 110 mm TL; Croatia: uppermost stream Norin at Prud, 43.095157 17,619551. Diagnosis. Lampetra soljani is distinguished from all other species of Lampetra species by having a marmorate flank pattern in live, fully grown ammocoetes, and in some adults (vs. plain colour pattern). It is further distinguished by a combination of characters. Lampetra soljani is most similar to L. lanceolata and L. ninae and is distinguished from these two species by having three velar tentacles (vs. 5 in L. lanceolata, 5-7 in L. ninae), no posterial teeth (vs. rarely absent, usually a single incomplete row with up to 23 teeth in L. ninae) and less trunk myomeres (trunk myomeres between last branchial opening and anus 54–57 vs. 57–64 in L. lanceolata, 57–61 in L. ninae; trunk myomeres between last branchial opening and first dorsal fin origin 28–32 vs. 32–36 in L. lanceolata, 32–35 in L. ninae; trunk myomeres between last branchial opening and second dorsal-fin origin 42–46 vs. 46–50 in L. lanceolata, 45–49 in L. ninae). Lampetra soljani is further distinguished from L. zanandreai by lacking posterial teeth (vs. usually present, very rarely absent). Lampetra zanandreai has a single row of posterials with up to 20 teeth but there are also individuals without posterial teeth (Hubbs & Potter 1971). Lampetra soljani is distinguished from L. fluviatilis and L. planeri by having a bicuspid middle endolateral tooth (vs. almost always tricuspid) and the infraoral lamina with 5 teeth (vs. usually 7–9, very rarely 5–6). The Portuguese species L. alavariensis, L. auremensis and L. lusitanica often, but not always, have a bicuspid middle endolateral tooth. Lampetra soljani is distinguished from L. alavariensis, L. auremensis and L. lusitanica by having 54–57 trunk myomeres between the last branchial opening and the anus (vs. 57–63). Lampetra fluviatilis has 58–69 trunk myomeres (n= 883 from more than 14 sites; Hardisty 1986a) and L. planeri has 54–69 trunk myomeres (n=2385 from 18 sites; Hardisty 1986b). However, 54 and 56 are minimum values of ammocoetes just from one site each and usually, the number of trunk myomeres ranges from 57–67 (mean 60–62) Description. For general appearance see Figs. 3–7. Morphometric data of pre-spawning adults are provided in Table 2. Oral discs are shown in Fig. 8. Trunk myomeres between last branchial opening and anus 54–57 (mode 55), between last branchial opening and origin of first dorsal-fin 28–32 (mode 28) and between last branchial opening and origin of second dorsal fin 42–46 (mode 43). Caudal fin spade like. Transverse lingual lamina not fully developed in individuals examined, with 0–4 (mode 2) unicuspid teeth on each side and one enlarged central tooth. In 14 individuals examined for this character, four without teeth on transverse lingual lamina and usually, there are 2–3 lateral teeth, 4 on one side in one individual. Longitudinal lingual laminae straight, each with 4–6 unicuspid teeth, no teeth seen in 12 out of 14 individuals examined. Supraoral lamina with two unicuspid teeth separated by a toothless bridge. Infraoral lamina with 5 teeth, outer two teeth bicuspid, inner three teeth unicuspid. Three bicuspid endolaterals on both sides of oral disc. Anterials in 1–2 rows, usually 1 row, inner row with 4–7 (mode 5 teeth) unicuspid teeth. Exolateral and posterial teeth absent. Three velar tentacles (n=6), middle one shorter than adjacent lateral tentacles, with tubercles on dorsal surface, without wings. Coloration. Ammocoetes (Fig. 7) are brownish along back with lighter undersides and a marmorate pattern on flank. Tail dark brown. Fins hyaline or pale yellowish-brown. Area around gill openings as well as in front of them reddish from blood vessels. Adults with brown back and upper flank, marmorate in some individuals, belly and lower flank silvery, yellowish in preserved individuals. All fins yellowish. A dark grey blotch near apex of second dorsal fin in some individuals (Figs. 3–5). Lateral-line neuromasts unpigmented on ventral surface and in prebranchial region. Distribution. Lampetra soljani is only known from the Neretva drainage in Croatia and Bosnia and Herzegovina. Lamprey from the Morača River drainage including Zeta River are preliminary identified as L. soljani based on molecular characters. The Morača River flows to Lake Skadar in Montenegro. The actually known distribution area is shown in Fig. 9 based on records listed in Table 3. Habitat and biology. Ammocoetes are found in silt, muddy or fine sandy-muddy sediment in river sections with slow or no current, in shallows at banks or backwaters at water depth of about 10–50 cm. Adults and ammocoetes are commonly caught together. First post-metamorphosis individual was found in September (FSJF 2184). Etymology. Named in honour of Tonko Šoljan (1907–1980) in appreciation of his contribution to the knowledge and development of ichthyology in Croatia and Bosnia and Herzegovina. Remarks. Lampreys from the Morača River drainage are identified as L. soljani based on the presented molecular characters. No adult individuals were available to us to test, if these agree with the diagnostic characters given here. Therefore, the identification is preliminary and should be tested in the future, when well-preserved adults become available. Posterial teeth are often deeply embedded in brook lampreys and we were unable to x-ray the mental disc in L. soljani. Due to the availability of so few adult individuals, we also did not apply any clearing and staining methods. Therefore, we cannot full exclude, that deeply embedded posterials, not visible externally, might be present. Lampreys are still a challenge for taxonomists and a good example for cryptic species exhibiting only few characters that can be reliably measured or counted (no fin rays, no scales, no ossified structures). Furthermore, lampreys show strong allometric growth after metamorphosis (Krappe 2004; see also differences in size and shape of body and fins in Fig. 5 +6) limiting morphometric studies to individuals in exactly the same phase of life. Krappe (2004) report growth of the disk and shrinkage of the body and tail between 5-15% after metamorphosis for different body proportions in L. planeri. Therefore, the traditional taxonomy in lampreys is mainly based on their dentition and the number of myomeres. Given that brook lampreys do not feed as adults, and hypothesized that they would use their teeth similarly to their predatory congeners, it can be speculated that the variation in tooth formulae and dentition might be a result of relaxed selection pressure. However, this hypothesis deserves a thorough testing and is far beyond the aims of our study. All brook lampreys have less and smaller teeth compared to their predatory congeners (Renaud 2011; Kottelat & Freyhof 2007). Potentially, all non-feeding species of Lampetra are satellite species of L. fluviatilis and have been isolated at different time periods from this predatory lamprey. It is likely, that all brook lampreys reduce the teeth and the degree of reduction might be related to the time, brook lamprey species or populations are isolated from their predatory congeners. Nr. Country Drainage Locality Coordinates Source With regard to the paucity of morphological characters compared to bony fishes, the inclusion of molecular genetic characters into standard taxonomic works in lampreys is of great value. A comprehensive, genome wide comparison of a predatory/non-feeding species pair from the same location (L. fluviatilis with L. planeri) revealed strong genetic differentiation, despite the existence of shared mitochondrial haplotypes in these two particular populations (Mateus et al. 2013b). In line with these findings, Rougemont et al. recently (2017) used RAD sequencing for a genome wide screening of SNP in nine different population species pairs in France and demonstrated again a strong genomic differentiation between the two species, but also showed levels of ongoing gene flow to correlate with geographic connectivity. All known brook lampreys included herein show differences in their mitochondrial DNA sequences between them (COI - this study; control region – Pereira et al. 2010; cytB – Mateus et al. 2013a), but no study exists that included the potential predatory sister taxon of the Eastern European species, so we do not know if the genome wide strong differentiation documented in Mateus et al. (2013b) and Rougemont et al. (2017) is the rule or an exception. Interestingly, while our samples of L. soljani show only a single, potentially diagnostic nucleotide substitution (position 460 C vs T) in their DNA barcode region, the four individuals analysed from the Morača River drainage exhibit two additional diagnostic positions, which are unique among all included specimens and can be perceived in the haplotype network (Fig. 2).

Nonparasitic Lethenteron reissneri (Dybowski) is redescribed based on four syntypes (two adults and two ammocoetes) from the Onon and Ingoda rivers, Russia, and 15 topotypic specimens (seven metamorphosing ammocoetes and eight ammocoetes) from the Onon River system, Russia and Mongolia. Posterial teeth were not mentioned in the original description, but Berg (1931) stated that they were sometimes absent, which he later (Berg 1948) changed to usually absent, based on material (some of which we have re-identified as parasitic Lethenteron camtschaticum) from far outside of the type locality. The latter view has been widely accepted by subsequent authors. Unfortunately, the poor condition of the two adult syntypes did not permit verification of this character. However, a row of posterials was clearly visible in six of the seven topotypic metamorphosing ammocoetes and indicates their usual presence in the species. The first full description of the ammocoetes, including pigmentation, is provided. The present study restricts the distribution of Lethenteron reissneri to the Shilka and Songhua river systems within the Amur River basin, until a more geographically comprehensive study is undertaken. Additionally, in this study, feeding versus non-feeding at the adult stage, are considered to be valid taxonomic characters at the species level.

Family Petromyzontidae Lethenteron appendix (DeKay) American Brook Lamprey Truttaedacnitis pybusae Entosphenus tridentatus (Gairdner) Pacific Lamprey Eustrongylides sp. Petromyzon marinus Linnaeus Sea Lamprey Truttaedacnitis truttae

Keys are provided for the identification of the nematode species known to be parasites of Canadian fishes. The nematodes are described and illustrated, with a note of the site(s) they occupy in named fish host(s) and their geographical distribution. Parasite records are given by author and date, full details of which can be found in a bibliography of over 800 references. Diagnoses and keys for 22 Families, 47 genera and 88 species of nematodes are also given, together with a glossary of terms, a host-parasite list, and indices to both nematode parasites and hosts.

Family Petromyzontidae Bonaparte 1831 Cyclostomes Duméril 1805:100 [ref. 1151] (family)? Petromyzon [latinized to Cyclostomia by Rafinesque 1815:94 [ref. 3584]; latinized to Cyclostomata by Goldfuss 1820:X, 106 [ref. 1829], by Schinz 1822:204 [ref. 3926] and by Richardson 1836:292 [ref. 3731]; latinized to Cyclostomi by Jarocki 1822:426, 458 [ref. 4984] and by Eichwald 1831:57 [ref. 5562]; no stem of the type genus, not available, Article 11Article 11.7.1.1] Lampredini Rafinesque 1810b:49 [ref. 3595] (ordine) “ Lampreda ” [published not in latinized form before 1900; not available, Article 11.7.2] Suceurs Cuvier 1816:116 [ref. 993] (family) Petromyzon [latinized to Suctorii; no stem of the type genus, not available, Article 11.7.1.1] Auloedibranchia Latreille 1825:111 [ref. 31889] (family) Petromyzon [no stem of the type genus, not available, Article 11.7.1.1] Les Pétromyzides Risso 1827:99 [ref. 3757] (family) Petromyzon [published not in latinized form before 1900; not available, Article 11.7.2] Petromyzonidae Bonaparte 1831:165, 189 [ref. 4978] (family) Petromyzon [stem corrected to Petromyzontby Owen 1846:48 [ref. 32214], confirmed by Girard 1858:376 [ref. 4911], by Günther 1870:499 [ref. 1995], by Steyskal 1980:173 [ref. 14191] and in ICZN Opinion 1171; family name sometimes seen as Petromyzidae or Petromysonidae] Ammocaetini Bonaparte 1846:9, 92 [ref. 519] (subfamily) Ammocoetus [as Ammocaetes, name must be corrected Article 32.5.3; corrected to Ammocoetina by Gray 1853:253 [ref. 1886]; stem changed to Ammocoete- by Bleeker 1859d:XXXIII [ref. 371]] Lampetrinae Fowler 1958b:1 [ref. 1470] (subfamily) Lampetra Entospheninae Vladykov 1972:148 [ref. 33046] (subfamily) Entosphenus, Published as part of Laan, Richard Van Der, Eschmeyer, William N. & Fricke, Ronald, 2014, Family-group names of Recent fishes, pp. 1-230 in Zootaxa 3882 (2) on page 15, DOI: 10.11646/zootaxa.3882.1.1, http://zenodo.org/record/7047777, {"references": ["Bonaparte, C. L. (1831) Saggio di una distribuzione metodica degli animali vertebrati, (1831), Roma, 78 pp. Saggio d'una distribuzione .. vertebrati a sangue freddo, (1832), Roma, 86 pp. also in Giornale Arcadico di Scienze Lettere ed Arti, 52 (1831), 155 - 189. Saggio di una distribuzione metodica deglianimali vertebrati (1832), 89 - 123. [pagination in all 4 works differs. We give those in`Giornale Arcadico' 52, often cited but perhaps not earliest] [ref. 4978]", "Dumeril, A. M. C. (1805) Zoologie analytique, ou methode naturelle de classification des animaux. Allais, Paris, xxxiii + 344 pp. [ref. 1151] http: // dx. doi. org / 10.5962 / bhl. title. 11646", "Rafinesque, C. S. (1815) Analyse de la nature, ou tableau de l'univers et des corps organises, Palerme, 224 pp. [Fishes on pp. 79 - 94] [before 21 July, ref. 3584]", "Goldfuss, G. A. (1820) Handbuch der Zoologie. Nurnberg, Band 1, xxiv + 510 pp., Pls. 1 - 2; Band 2, xlvi + 696 pp., Pls. 3 - 4. [Fishes in Volume 1] [ref. 1829]", "Schinz, H. R. (1822) Das Thierreich eingetheilt nach dem Bau der Thiere als Grundlage ihrer Naturgeschichte und der vergleichenden Anatomie. Mit vielen Zusatzenversehen von H. R. Schinz Band 2. Cotta, Stuttgart & Tubingen, xvi + 835 pp. [a translation, with emendations, of Cuvier's \" Regne animal 1816 \" [ref. 993], includes new names given by Schinz; see also Daget, J. (1968) Les poissons dans l'edition allemande du Regne Animal de Cuvier. Bulletin du Museum National d'Histoire Naturelle, Serie 2, 39 (6) (1967), 1057 - 1059] [ref. 3926]", "Richardson, J. (1836) Fauna Boreali-Americana; or the zoology of the northern parts of British America: containing descriptions of the objects of natural history collected on the late northern land expeditions, under the command of Sir John Franklin, Part 3 The Fish. Bentley, London, xv + 327 pp., Pls. 74 - 97. [ref. 3731] http: // dx. doi. org / 10.1017 / cbo 9781139151917.005", "Jarocki, F. P. (1822) Zoologiia czyli zwierzetopismo ogolne podlug naynowszego systematu, volume 4. Drusarni Laukiewicza, Warszawie (Warsaw), 464 + xxvii pp.", "Eichwald, C. E. von (1831) Zoologia specialis quam expositis animalibus tum vivis, tum fossilibus potissimum Rossiae, in universam, et Poloniae in specie, ... Wilna. Pars posterior [3], 404 pp. [3 parts in 2 vols., 1829 - 31, Pisces are pp. 57 - 116] [ref. 5562] http: // dx. doi. org / 10.5962 / bhl. title. 51803", "Rafinesque, C. S. (1810 b) Indice d'ittiologia siciliana; ossia, catalogo metodico dei nomi latini, italiani, e siciliani dei pesci, che si rinvengono in Sicilia disposti secondo un metodo naturale e seguito da un appendice che contiene la descrizione de alcuni nuovi pesci siciliani. Presso Giovanni del Nobolo, Messina, 70 pp., Pls. 1 - 2. [author given as Rafinesque Schmaltz, C. S. (this name was used by Rafinesque between 1810 and 1814), we use Rafinesque for simplicity] [ref. 3595] http: // dx. doi. org / 10.5962 / bhl. title. 6893", "Cuvier, G. (1816) Le Regne Animal distribue d'apres son organisation pour servir de base a l'histoire naturelle des animaux et d'introduction a l'anatomie comparee. Les reptiles, les poissons, les mollusques et les annelides, Tome II, Deterville, Paris, xviii + 532 pp., [Pls. 9 - 10] [November, ref. 993] http: // dx. doi. org / 10.5962 / bhl. title. 41460", "Latreille, P. A. (1825) Familles naturelles du regne animal, exposees succinctement et dans un ordre analitique, avec l'indication de leurs genres. J. - B. Bailliere, Paris, 570 pp. [ref. 31889] http: // dx. doi. org / 10.5962 / bhl. title. 16094", "Risso, A. (1827) Histoire naturelle des principales productions de l'Europe meridionale, et particulierement de celles des environs de Nice et des Alpes maritimes Tome 3. F. G. Levrault, Paris & Strasbourg, xvi + 480 pp., 16 Pls. [22 September, ref. 3757] http: // dx. doi. org / 10.5962 / bhl. title. 58984", "Owen, R. (1846) Lectures on the comparative anatomy and physiology of the vertebrate animals delivered at the Royal College of Surgeons of England 1844 and 1846. Part I. Fishes. Longman, Brown, Green and Longmans, London, xi + 308 pp. [ref. 32214] http: // dx. doi. org / 10.5962 / bhl. title. 13539", "Girard, C. F. (1858) Fishes in: General report upon zoology of the several Pacific railroad routes, 1857. In: Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean, 10. Beverley Tucker, Washington, D. C., pp. i - xiv, 1 - 400, Pls. 7 - 8, 13 - 14, 17 - 18, 22 c, 26, 29 - 30, 34, 37, 40 - 41, 48, 53, 59, 61, 64 - 65, 71. [ref. 4911]", "Gunther, A. (1870) Catalogue of the fishes in the British Museum. Catalogue of the Physostomi, containing the families Gymnotidae, Symbranchidae, Muraenidae, Pegasidae, and of the Lophobranchii, Plectognathi, Dipnoi, .. [thru] .. Leptocardii, in the British Museum, Volume 8. British Museum, London, xxv + 549 pp. [25 June, ref. 1995] http: // dx. doi. org / 10.5962 / bhl. title. 8329", "Steyskal, G. C. (1980) The grammar of family-group names as exemplified by those of fishes. Proceedings of the Biological Society of Washington, 93 (1), 168 - 177. [ref. 14191] http: // www. biodiversitylibrary. org / page / 34557938", "Bonaparte, C. L. (1846) Catalogo metodico dei pesci europei. Atti della Settima Adunanza degli Scienziati Italiani 7 a Adunanza, (1845), Napoli, Part 2, 1 - 95. [also issued as separate, Napoli, 1846, 97 pp.] [ref. 519]", "Gray, J. E. (1853) Description of a new form of lamprey from Australia, with a synopsis of the family. Proceedings of the Zoological Society of London, 1851 (19), 235 - 241, Pls. 4 - 5. [also in Annals and Magazine of Natural History, Series 2, 13 (1854), 58 - 65] [26 July, ref. 1886]", "Bleeker, P. (1859 d) Enumeratio specierum piscium hucusque in Archipelago indico observatarum, adjectis habitationibus citationibusque, ubi descriptiones earum recentiores reperiuntur, nec non speciebus Musei Bleekeriani Bengalensibus, Japonicis, Capensibus Tasmanicisque. Acta Societatis Regiae Scientiarum Indo-Neerlandicae [Verhandelingen der Natuurkundige Vereeniging in Nederlandsch Indie], 6, I-XXXVI + 1 - 276. [

Family Geotriidae Gill 1893 Geotrinae Gill 1893b:129 [ref. 26255] (subfamily) Geotria [genus inferred from the stem, Article 11.7.1.1; stem corrected to Geotri- by Whitley 1932c:261 [ref. 17971], confirmed by Myers & Storey 1956:16 [ref. 32831], by Nelson 1976:22 [ref. 32838], by Nelson 2006:26 [ref. 32486] and by Renaud 2011:16 [ref. 31770]], Published as part of Laan, Richard Van Der, Eschmeyer, William N. & Fricke, Ronald, 2014, Family-group names of Recent fishes, pp. 1-230 in Zootaxa 3882 (2) on page 15, DOI: 10.11646/zootaxa.3882.1.1, http://zenodo.org/record/7047777, {"references":["Gill, T. N. (1893 b) Families and subfamilies of fishes. Memoirs of the National Academy of Science, 6 (6), 127 - 138. [ref. 26255]","Whitley, G. P. (1932 c) The lancelets and lampreys of Australia. Australian Zoologist, 7 (3), 256 - 264, Pl. 13. [15 September, ref. 17971]","Myers, G. S. & Storey, M. H. (1956) Curatorial practices in zoological research collections 2. System followed in filing specimens of Recent fishes in the natural history museum of Stanford University. Circular Number 6 of the Natural History Museum of Stanford University, i-viii + 1 - 44 [originally compiled in December 1939, emended 1939 - 1956; on the cover of the Circular: \" They are not generally available or for sale \"; work not published according to ICZN Article 8.1] [October, ref. 32831]","Nelson, J. S. (1976) Fishes of the World. John Wiley & Sons, New York, xiii + 416 pp. [ref. 32838]","Nelson, J. S. (2006) Fishes of the World, 4 th edition. John Wiley & Sons, New York, xix + 601 pp. [ref. 32486]","Renaud, C. B. (2011) Lampreys of the World. An annotated and illustrated catalogue of lamprey species known to date. FAO Species Catalogue for Fishery Purposes No. 5, Food and Agriculture Organization of the United Nations, Rome, vi + 109 pp. [ref. 31770]"]}

Laan, Richard Van Der, Eschmeyer, William N., Fricke, Ronald (2014): Family-group names of Recent fishes. Zootaxa 3882 (2): 1-230, DOI: http://dx.doi.org/10.11646/zootaxa.3882.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3882.1.1

Family Mordaciidae Gill 1893 Name in prevailing recent practice, Article 35.5 Caragolinae Gill 1883b:524 [ref. 4941] (subfamily) Caragola [family-group name used as valid after 1899, e. g. by Fowler 1964:33 [ref. 7160]] Mordaciidae Gill 1893b:129 [ref. 26255] (family) Mordacia [genus inferred from the stem, Article 11.7.1.1; family-group name used as valid by: Fontaine 1958, Hubbs & Potter 1971 [ref. 13397], Lindberg 1971 [ref. 27211], Nelson 1976 [ref. 32838], Shiino 1976, Bailey 1980 [ref. 5253], Nelson 1984 [ref. 13596], Nelson 1994 [ref. 26204], Allen, Midgley & Allen 2002 [ref. 25930], Nelson 2006 [ref. 32486], Renaud 2011 [ref. 31770]], Published as part of Laan, Richard Van Der, Eschmeyer, William N. & Fricke, Ronald, 2014, Family-group names of Recent fishes, pp. 1-230 in Zootaxa 3882 (2) on page 15, DOI: 10.11646/zootaxa.3882.1.1, http://zenodo.org/record/7047777, {"references":["Gill, T. N. (1883 b) Note on the petromyzontids. Proceedings of the United States National Museum, 5 (310), 521 - 525. [3 April, ref. 4941] http: // dx. doi. org / 10.5479 / si. 00963801.5 - 310.521","Fowler, H. W. (1964) A catalog of World fishes [Part I]. Quarterly Journal of the Taiwan Museum (Taipei), 17 (3 / 4), 1 - 62. [ref. 7160]","Gill, T. N. (1893 b) Families and subfamilies of fishes. Memoirs of the National Academy of Science, 6 (6), 127 - 138. [ref. 26255]","Fontaine, M. (1958) Classe des cyclostomes, biologie. In: Grasse, P. P. (Editor), Traite de Zoologie Tome 13 Fascicule 1, Masson & Cie, Paris, pp. 111 - 172.","Hubbs, C. L. & Potter, I. C. (1971) Distribution, phylogeny and taxonomy. In: Hardisty, M. W. & Potter, I. C. (Editors), The Biology of Lampreys. Academic Press, New York, pp. 1 - 65. [ref. 13397]","Lindberg, G. U. (1971) Opredelitel' i kharakteristika semeystv ryb mirovoy fauny [Families of the fishes of the world: a check list and a key]. Nauka, Leningrad, 472 pp. [in Russian. English translation by Hardin, H. (1973), Fishes of the world: a key to families and a checklist, Israel Program for Scientific Translations, distributed by John Wiley & Sons, New York, 545 pp.] [2 August, ref. 27211]","Nelson, J. S. (1976) Fishes of the World. John Wiley & Sons, New York, xiii + 416 pp. [ref. 32838]","Shiino, S. M. (1976) List of common names of fishes of the world, those prevailing among English-speaking nations. Science Report of Shima Marineland, 4, 1 - 262.","Bailey, R. M. (1980) Comments on the classification and nomenclature of lampreys - an alternative view. Canadian Journal of Fisheries and Aquatic Sciences, 37 (11), 1626 - 1629. [ref. 5253] http: // dx. doi. org / 10.1139 / f 80 - 209","Nelson, J. S. (1984) Fishes of the World, 2 nd edition. John Wiley & Sons, New York, xv + 523 pp. [ref. 13596]","Nelson, J. S. (1994) Fishes of the World, 3 rd edition. John Wiley & Sons, New York, xvii + 600 pp. [ref. 26204]","Allen, G. R., Midgley, H. & Allen, M. (2002) Field guide to the freshwater fishes of Australia. Western Australian Museum, Perth, xiv + 394 pp. [ref. 25930]","Nelson, J. S. (2006) Fishes of the World, 4 th edition. John Wiley & Sons, New York, xix + 601 pp. [ref. 32486]","Renaud, C. B. (2011) Lampreys of the World. An annotated and illustrated catalogue of lamprey species known to date. FAO Species Catalogue for Fishery Purposes No. 5, Food and Agriculture Organization of the United Nations, Rome, vi + 109 pp. [ref. 31770]"]}

Lampetra soljani , new species, is described from the lower Neretva River in the Adriatic Sea basin. Previously it was identified as L. zanandreai . Based on morphological similarity and mitochondrial genetic data, it is related to L. lanceolata and L. ninae from the Black Sea basin. Lampetra soljani is distinguished from all other species of Lampetra by having a marmorate flank pattern in live, fully grown ammocoetes, and in some adults (vs. plain colour pattern). Lampetra soljani is distinguished from other Lampetra species by having three velar tentacles, 54–57 trunk myomeres between the last branchial opening and the anus, no posterial teeth and a bicuspid middle endolateral tooth. Lampetra soljani is also well distinguished by COI barcode data from its congeners. The new species is widespread in the Neretva River drainage and lampreys from Lake Skadar basin are likely to belong to this species also.

* Petromyzon marinus Linnaeus, 1758 – Sea lamprey; Lampreia-do-mar ①③, Published as part of Carneiro, Miguel, Martins, Rogélia, Landi, Monica & Costa, Filipe O., 2014, Updated checklist of marine fishes (Chordata: Craniata) from Portugal and the proposed extension of the Portuguese continental shelf, pp. 1-73 in European Journal of Taxonomy 73 on page 9, DOI: 10.5852/ejt.2014.73, http://zenodo.org/record/3866515

The study of the Portuguese marine ichthyofauna has a long historical tradition, rooted back in the 18th Century. Here we present an annotated checklist of the marine fishes from Portuguese waters, including the area encompassed by the proposed extension of the Portuguese continental shelf and the Economic Exclusive Zone (EEZ). The list is based on historical literature records and taxon occurrence data obtained from natural history collections, together with new revisions and occurrences. It comprises a total of 1191 species, distributed among 3 superclasses, 4 classes, 42 orders, 212 families and 617 genera. If considering only the EEZ and present territorial waters, this list represents an increase of 230 species (27.8%) and of 238 species (29.0%), when compared to the information available in FishBase (2012) and in the last checklist of marine and estuarine fishes of Portugal (1993), respectively. The order Perciformes shows the highest diversity, with 54 families, 162 genera and 299 species. Stomiidae (80 species), Myctophidae (71 species) and Macrouridae (37 species) are the richest families. From the listed species, 734 are present off mainland Portugal, 857 off the Azores and 766 off Madeira. Within the limits of the examined area, three species are reported for the first time in mainland Portugal and twenty-nine records are identified as doubtful. A total of 133 species have been recorded from the extended Portuguese continental shelf (2 off mainland Portugal, 117 off the Azores and 14 off Madeira), two of which are common to the Azores and Madeira extensions. Biogeographically, the Atlantic group is the most important (548 species – 46.01%), followed by the Lusitanian group (256 species – 21.49%), the African group (71 species – 5.96%), the Boreal group (34 species – 2.85%), the Mediterranean group (31 species – 2.60%), the Macaronesian group (21 species – 1.76%), the Atlantic/African group (19 species – 1.60%) and the Mediterranean/African and the Arctic groups, each with only 1 species (0.08%). Regarding the preferences for vertical habitat, the demersal fishes are the most important group (305 species – 25.61%), followed by the mesopelagic group (228 species – 19.14%), the bathypelagic group (164 species – 13.77%), the benthopelagic group (147 species – 12.34%), the bathydemersal group (115 species – 9.66%), the reef-associated group (88 species – 7.39%), the pelagic group (74 species – 6.21%), the epipelagic group (58 species – 4.87%) and 1 species (0.08%) of the benthic group. The oceanic habitat is the best represented group comprising 446 species (37.45%), followed by the shelf group (199 species – 16.71%), the slope group (164 species – 13.77%), the inner shelf group (89 species – 7.47%), the coastal group (70 species – 5.88%), the outer shelf group (29 species – 2.43%) and the oceanic/shelf group (7 species – 0.59%).

Lampetra fluviatilis (Linnaeus, 1758) – River lamprey; Lampreia-do-rio ①, Published as part of Carneiro, Miguel, Martins, Rogélia, Landi, Monica & Costa, Filipe O., 2014, Updated checklist of marine fishes (Chordata: Craniata) from Portugal and the proposed extension of the Portuguese continental shelf, pp. 1-73 in European Journal of Taxonomy 73 on page 9, DOI: 10.5852/ejt.2014.73, http://zenodo.org/record/3866515