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This study described the detailed osteological features of the Setouchi salamander Hynobius setouchi. H. setouchi, which is endemic to central Japan, was recently delineated from the wide range of H. nebulosus species based on molecular and external morphological characteristics. However, the osteological features of the species belonging to the genus Hynobius have not been examined, which has hindered the detailed understanding of morphological diversity in the genus. To address this problem, this study elucidated the osteological features of the salamander using micro-computed tomography scanning and whole-mount double staining methods. The articular, a part of the hypobranchial I, a part of coracoid, pubis, carpus, and tarsus were cartilaginous in small-sized individuals and were partially or completely ossified in large-sized individuals. The degree of ossification varied in the operculum, basibranchial II, and ascending process of the palatoquadrate. However, ossification was not associated with body size. The lacrimal, ossified manus, and ossified pes exhibited varying degrees of articulation or fusion irrespective of body size. Moreover, the cranium and tarsus of H. setouchi exhibited several unique characteristics. These osteological characteristics will aid in revising the taxonomy and phylogeny of the Hynobius species.

Recently, the culture of American eels (Anguilla rostrate) in China has been impacted by emergence of a disease with signs of haemorrhagic gill necrosis. The gills of diseased eels are covered with petecchia and they bleed when the operculum is pressed. In this study, a novel American eel adomavirus (AEAdoV) was isolated from the diseased eels using the eel ovary cell line (EO). The virus proliferated in the EO cells with a maximum TCID50 /ml of 106.29 ± 0.23 at 6 days post-infection. The virions were non-enveloped with a diameter of 75-85 nm and shown to be a DNA virus upon 5-iodo-2'-deoxyuridine (IDU) treatment. PCR assays showed that AEAdoV encodes a superfamily 3 helicases (S3H) replicase and shared high similarities with Anguilla marmorata adomavirus (MEAdoV). Although no clinical signs or mortality was observed among the eels injected with AEAdoV, the virus was reisolated from livers, kidneys and gills of injected eels at 35 days post-injection. Our results suggested that AEAdoV exhibited a latent infection in A. rostrata. The pathogenicity of the AEAdoV needs to be confirmed further.

The biometric characteristics of Trachinus araneus, Trachinus draco and Trachinus radiatus from the Egyptian Mediterranean waters at the West of Alexandria City, were studied. In total, 105, 96 and 55 specimens of these three Fish species were sampled, respectively, by the use of bottom trawls operated in the sectors of El-Dabaa and Sidi Abd El Rahman. The morphological characteristic and related index ratio were determined. The results showed that T. araneus total length varied from 10.9 to 30.0 cm TL with mean length of 19.87 ± 5.43 cm TL and a number of horizontal dots appear to be distributed along the lateral line, T. draco total length was 11.8 to 27.6 cm TL with a mean length of 17.85 ± 4.23 cm TL, and specimens of this Fish species showed yellow vertical oblique lines on the body. On the other hand, T. radiatus is characterized by a total length of 10.6 to 35.0 cm TL with a mean length 18.04 ± 4.87 cm TL, and by circular brown dots spread on the whole body and head. Furthermore, these three Fish species have poisonous spines, one on each operculum, and both spines on the internal border of the dorsal part of each eye orbit. The morphometric regression of each morphometric character showed close agreement between the observed and calculated values.

The foraging and feeding behaviours of the Asian Openbill Stork (Anastomus oscitans) were observed in several paddy fields in Thailand, on food items not previously reported. Foraging and feeding techniques of the storks were similar to those described in the literature, except at one site where a peculiar new foraging behaviour was observed. Here, the storks fed on exotic Golden Apple Snails (Pomacea canaliculata) by using their bills to puncture the shells for extracting the soft snail bodies. The shells of large snails discarded by storks tended to be more damaged than those of small snails, due to the difficulty of extraction. Analyses of stork’s droppings and their regurgitated food showed that the bulk was of plant materials and shelled snails (mainly P. canaliculata and Filopaludina spp.). Adult storks tended to consume the whole soft bodies of the snails, including viscera, and sometimes the entire snails, including with their hard shells and opercula still attached. Although the storks could feed potentially on the entire snail body, the birds were seen to discard the male’s testes and female’s albumen glands of P. canaliculata at these feeding grounds, also evident in their regurgitates. Crushing of snail shells was not evident, but sometimes, pounding the shell and/or swallowing the entire shell and its operculum were supported by observations.

The craniological analysis of Cobitis derzhavini from the Mingechaur Reservoir system and C. saniae from the Malyi Kyzylagach Bay drainage and the Alvady River in Azerbaijan did not reveal any fundamental differences in the general morphology of the neurocranium and cranial bones between these species, as well as from the previously studied C. taenia, C. melanoleuca and C. taurica. However, C. derzhavini showed high level of diversity from other Cobitis species in the proportions of some bones, at first, operculum. The results confirm that C. derzhavini is a separate species characterized by a predominance of opercular bone with weakly excised posterior margin, in contrast to opercular bone with deeply excised posterior margin observed in other craniologically studied species of Cobitis and Sabanejewia.

The jaws of vertebrates display a striking diversity in form and function, but they typically open and close like a trapdoor rather than sliding like a saw. Here, we report unique feeding behaviour in the blunt-headed snail-eating snake, Aplopeltura boa (family Pareidae), where the snake cuts off and circumvents the indigestible part (the operculum) of its prey in the mouth using long sliding excursions of one side of the mandible, while the upper jaws and the mandible on the other side maintain a stable grasp on the prey. This behaviour, which we call ‘mandibular sawing’, is made possible by extraordinarily independent movements of the jaw elements and is a surprising departure from usual feeding behaviour in vertebrates., ヘビが顎をノコギリのように使うことを発見 --ボルネオ島での爬虫両生類の生態調査で--. 京都大学プレスリリース. 2020-07-31.

Several marine gastropods are known to have high economic value, one of which is the Spiral babylonia snail. They commonly exploited for meat, shell, or operculum. Tiger snail meat is commonly exported and consumed by fishermen. Its shell is used as a material for industrial lime and for omamen. Operculum is commonly used as a medicinal and perfume ingredient). However, the recent production has decreased due to the limited information of seasonal catch. One way to overcome these obstacles is through culture activities. The provision of seeds is an important link in the culture system, therefore the study of the spawning process and larval development is an important requirement for the development of larval rearing techniques. This study aims to determine the development process of juvenil eggs and the survival rate of tiger snails reared in the laboratory.. The study was conducted at the Laboratory of Marine Farm Subdivision in Kudus, Pt Pura Bahari, Jepara Regency. This sudy used experimental method with descriptive data analysis. Adult tiger snails were caught from Bunga waters, Demak. The snails were reared in a rectangular tube filled with 15 cm filtered sea water and 5 cm of sand. Egg capsules were reared in a 4 liters circular tube with continuous aeration. The hatched larvae were reared in a 300 liters circular tube filled with filtered seawater, continuously aerated and fed with Chlorella plankton . Our result showed that tiger snails spawn naturally and produce egg capsules. The incubation period for the capsule is 6 days, then develop into veliger larva for 12 days. The veliger larvae metamorphosed,and become juvenil. The lowest survival rate observed in the veliger stage. The survival rate of the egg and the intracapsular trochopore stages were quite high (tube I = 98.413%; tube II = 98.238%; tube III = 90.476%), then the lowest was in the veliger stage (tube I = 3,468%; tube II = 2.603%; tube III = 2,598%) and the juvenil stage is quite high compared to the previous phase (tube I = 3,413%; tube II = 2,479%; tube III = 2,351%).

The behavior of Betta sp. was very much influenced by nutritious food. The method used is descriptive that is measuring weight gain and body length and survival in the control treatment (0%), 25%, 50%, 75% and 100%, then also observed pre fighting behavior which includes opening operculum, tail flix, tail fin and stering and also fighting behavior was observed. The results showed that starting from weight gain, the length of all BSF treatments was higher than the control, then all treatments were also crossed, for Pre fighting operculum opening, tail flixes, tail fin and stering for various treatments BSF was also better than the control so it was also in fights shows all BSF treatment wins against control.

The number of freshwater species belonging to the genus Parastenocaris reported from ten countries of Southeast Asia is quite limited. Only two species have been reported so far from freshwater habitats there, compared to over 290 described species of the family Parastenocarididae worldwide. During the first study of the hyporheic zone of two small rivers in central Vietnam, two new species of the family Parastenocarididae were collected, Parastenocaris sontraensis sp. nov. and Parastencaris vugiaensis sp. nov. Both were collected from the gravel bar along the rivers (Suoi Da and Vu Gia river) using the Karaman–Chappuis method. Both the new species belong to the brevipes group of the genus Parastenocaris Kessler, 1913 sensu Lang (1948), and Reid (1995). Parastenocaris sontraensis sp. nov. is similar to P. hinumaensis Kikuchi, 1970 and Parastenocaris jane Karanovic, 2006 in the brevipes-group. Parastenocaris sontraensis sp. nov. differs from both Parastenocaris species by (i) Exp P3 with three segments in the male, (ii) caudal rami with seven setae, and (iii) caudal rami about 2.4 times as long as wide. Parastencaris vugiaensis sp. nov. can be distinguished from its congeners by the unique combination of the following characters: (i) the elliptical shape of caudal rami, (ii) apical seta (V) with bulbous base, and (iii) anal operculum extends beyond the end of anal somite. Until now, 14 stygobiotic species of Copepoda have been recorded in Vietnam (including two new species in this paper), which is relatively few compared with nearby Thailand with 25 species. Short comments on other stygobiotic Copepoda from Vietnam are added.

Profundulus adani, new species, is described from the upper reaches of the Papaloapan River in the Mexican state of Oaxaca. The uniqueness of this new species is supported by morphological and molecular evidence. A combination of color patterns and counts separate P. adani, new species, from its congeners. Profundulus adani, new species, is distinguished from all congeners by the absence of a humeral spot in individuals larger than 45 mm SL. It can further be distinguished from P. balsanus, P. chimalapensis, P. kreiseri, P. oaxacae, P. parentiae, and P. punctatus based on the absence of series of dark dots on the sides of the body. Profundulus adani, new species, shows a faded dark band that extends from the tip of the operculum to the end of the caudal peduncle; this band is absent in P. balsanus and P. parentiae. The new species is described using specimens collected in the upper reaches of the Papaloapan River in the Mexican state of Oaxaca; geographically this represents a significant range expansion and extends the Atlantic slope northernmost limit of the Profundulidae.

Both sexes of a new species, Stylicletodes wellsi sp. nov. (Harpacticoida: Cletodidae), are described from material collected from sediments in the East China Sea. The new species belongs to a species group whose members are characterized by an anal operculum that has a backwardly directed, median linguiform process and fifth legs that display naked or sparsely pinnate armature elements in both sexes. Within this group, S. wellsi sp. nov. is morphologically closest to S. reductus Wells, 1965 but differs primarily from its European congener in the armature pattern of P4 (both rami) and the female P5. Distribution records of all species are summarized and an updated identification key to the seven valid species in the genus is presented. Taxonomic issues related to the type species S. longicaudatus (Brady, 1880) are briefly discussed.

The discrimination of developmental stages of anurans is of critical importance in understanding the morphological characteristics of each specific stage of tadpoles. Unlike most rhacophorids which construct foam nest during egg deposition, Kurixalus naso shows no foam formation during oviposition. This rhacophorid displays a unique oviposition whereby the eggs are laid in the moist soil under burrows and mixed with the loose top layer of the soil giving those eggs a seed-like appearance. The present study highlighted and documented the developmental stages of Kurixalus naso until complete metamorphosis. A normal developmental table consisting of 46 developmental stages was proposed for Kurixalus naso. Stages of development and metamorphosis of Kurixalus naso were divided into 11 major developmental terms, each consisting of a number of successive stages: fertilization (stages 1–2), cleavage-blastula (stages 3–9), gastrula (stages 10–12), neurula (stages 13–16), tail bud stages (stages 17–20), external gill stages (stages 21–22), operculum and oral disc stages (stages 23–25), hind limb bud formation (stages 26–30), toe differentiation and development (stages 31–39), well-developed hind limb (stages 40–41) and metamorphosis (stages 42–46). The embryos of this species hatched into a free-swimming tadpole at stage 25. Kurixalus naso completed the entire process of development and metamorphosis over 62 days. This investigation may contribute to future studies on evaluation of adaptive characters, comparative embryology, and other developmental studies, associated with phylogenetic inferences.

A single specimen of Oriostoma globosum (von Schlotheim, 1820) from the Silurian-age (Wenlockian) Laurel Limestone in southeastern Indiana preserves a partial, multispiral operculum in situ within the aperture. Only eight specimens of in situ Oriostoma opercula have previously been illustrated from Canada and Europe, and this is the first from the United States. Oriostoma huntingtonensis Kindle, 1904, from younger Silurian (Ludlovian–Pridolian) strata in northern Indiana is considered a synonym of the more widespread O. globosum, and it was described as having associated loose multispiral calcareous opercula in the same strata.

The work under investigation is carried out to describe the gross morphology and ultrastructure of the gills of the species Bagrus bayad grossly and with the help of scanning electron microscopy. The current work carried on ten fresh adult Bagrus bayad. Bagrus bayad is a genus of the Bagridae family. Our results revealed that the operculum opened caudoventrally. The wide interbranchial septum consisted of four transverse raised areas on each side that connected by transverse lines caudal to the base of the tongue. The gill arch is divided into long ceratobranchial and the short epibranchial clearly and formed an angle between them in the first three gill arches but in the fourth-gill arch is not clear. The first two gill arches have only lateral rackers. The first arch carried well-developed long rackers while rackers on the following rows were short. The majority of gill rackers were short as an adaptation of the carnivorous feeding habit of the Bagrus bayad. The gill arch and rackers were covered by pavement cells with chloride and mucus cells. The pavement cell surface has numerous microridges giving them the fingerprint's appearance. The gill filament's length is nearly fixed along the entire gill arch. Along the gill arch, and the gill filament carried leaf-like gill lamellae. At higher magnification, the gill filament appeared covered by irregular polygonal cells that have concentric microridges.

Pomatostegus Schmarda, 1861 is a serpulid genus with three recognized species, mostly from tropical waters. Pomatostegus stellatus (Abildgaard, 1789), was described from the Caribbean Sea, and has been widely recorded in the Pacific and Indian oceans; P. kroyeri Mörch, 1863 was described from Puntarenas, Costa Rica; however, most records from the Tropical Eastern Pacific were referred to P. stellatus. In this work, the two species are redescribed using morphological characters. The main differences are in the shape of the Spirobranchus-type collar chaetae, opercular plate shape and the number of “free” circlets of spines without accompanying of opercular plates. Comments about characters of P. actinoceras Mörch, 1863, described from Philippines, and an identification key for the three species, are included.

Sexual dimorfism refers to morphological differences between males and females of a species. It may be a result of different selection pressures acting on either or both sexes and may occur in any sexually-reproducing dioecious species, including fishes. We analyzed 63 females and 63 adult males of Gymnorhamphichthys rondoni (Gymnotiformes) collected by us or deposited in museum collections. Sex was identified through abdominal dissection. We measured length from snout to posterior end of anal-fin, anal-fin length, distance from anus to anal-fin origin, distance from genital papilla to anal-fin origin, body width at beginning of anal-fin, and head length. Morphometric data submitted to a Principal Component Analysis (PCA) grouped males and females according to variables related to body size (along the first component) and to head length and body height along the second and third components. Females were larger than males, whereas males had proportionally larger heads and higher bodies than females. The urogenital papilla of males and females showed differences in shape, size and relative position on the body. The female papilla was elongated horizontally, larger than that of males, and was located on a vertical line below the eye, while the papilla of the males was vertically elongated and located on a vertical line below the operculum. To our knowledge, this is the first recorded case of sexual dimorphism in a species of Rhamphichthyidae, a condition that is now known in all the currently recognized families of Gymnotiformes. © 2019, Instituto Nacional de Pesquisas da Amazonia. All rights reserved.

This study attested the anatomical and morphometrical descriptions of the nasal cavity in duck, goose as the aquatic birds and quail, dove as the non-aquatic birds. This study elucidated in the aquatic birds that the nasal cavity remarkable increased in width caudally and had relatively larger nasal conchae and greater of the middle nasal concha than the non-aquatic birds. The nostrils without operculum in the aquatic birds and with horny operculum in the non-aquatic birds, it located at the base of the upper beak by variable distances but in quail, it located punctually at the base of the beak. In all examined birds, the nasal cavity consisted of three nasal conchae except dove consisted of two conchae. The middle nasal concha length constituted the highest percentage to that of the nasal cavity which was recorded 63.91%, 55.18%, and 58.88% in duck, goose and quail respectively except in dove the caudal one recorded the highest percentage 42.16%. In transverse sections, the rostral nasal concha projected from the lateral wall of the nasal cavity as a shelf-like in duck, T-shape in goose and appeared as very small bulla in dove as well as it was C shape enclosed vertical lamella of the nostril in quail. The middle one scroll one and one-half turns in duck, two turns in goose, one-half turn in quail and absent in dove. The caudal nasal concha in duck, goose, and quail was bulla-like and hollow pear-shaped in dove. The infra-orbit sinus was well developed in the aquatic birds than that of the non-aquatic birds.

The aim of this study was to determine the median lethal concentration LC50 24 h of formalin in Xiphophorus maculatus, Xiphophorus heleri, Oreochromis niloticus, Danio rerio, and Carassius auratus. The concentrations of 100, 150, and 200 mg L−1 were tested in each fish species separately. Fish behavior was observed in the first 6 h after exposure to formalin. The 200 mg L−1 concentration was the most lethal for all species in less than 24 h. Tilapia was the most resistant species with a LC50 24 h achieving 191.34 mg L−1. In the first 2 h, the behaviors of fish on the higher concentration were agglomeration near the aeration input in the tanks and agitated swimming with fast movement of opening and closing of both mouth and operculum. With more than 4 h exposure, an increase in mucus production was observed, promoting a change in water color, reduction of operculum beating, and slow swimming until the beginning of the first deaths. We recommend using 100 mg L−1 of formalin for prophylactic baths during 1 h or two baths with 50 mg L−1 for 30 min for juvenile fish, in two consecutive days to ensure the fish welfare post-bath, as well as the health of those who will manipulate the formalin.

Gastropods are generally rare in amber. In this paper we describe an example of exceptional soft-bodied preservation in a fossil terrestrial mollusk-a snail shell with some tissue, including part of the cephalic region (head) with a tentacle and inferred eye stalk, and potentially part of the foot and operculum. The snail, a probable juvenile, is preserved in Burmese amber (Burmite) from Myanmar, of earliest Cenomanian age. Morphological evidence suggests a cyclophoroidean ancestry and a possible attribution to the family Cyclophoridae; members of this superfamily are widespread today in Asia, thus indicating a long geological history in the region. This specimen constitutes the first confirmed and oldest record of soft-bodied preservation of a snail in Cretaceous amber.

The unique Silurian gastropod with the operculum in place which Edgar E. Teller in 1910 assigned to Murchisonia conradi Hall is redescribed. The date of authorship of Murchisonia conradi Hall, now ...

Purpose Using direct intracerebral electrical stimulation (ES) in epileptic patients to evoke symptoms to help identify the functional neuroanatomy of the insular lobe and opercula. Methods We selected 43 patients who had at least 1 electrode inserted into the insula or opercula via an oblique approach among 135 patients with intractable epilepsy. Bipolar stimulation was chosen, and the stimulation parameters of the biphasic waves included a pulse width of 0.2 ms, a frequency of 50 Hz, a duration of 3 s, and an intensity gradually increasing from 0.5 to 4 mA. Results In total, 93 electrodes were implanted into the insula or insular opercula, and 169 of 281 contacts (60.1%) evoked 212 responses by ES of the insula. 142 responses were induced by stimulating the insular opercula in 126 of 343 sites (36.7%). Usual responses, such as somatosensory, visceral sensory, speech, auditory, and motor responses, were evoked. In addition, rarely reported responses, including cardiovascular symptoms (tachycardia), visual symptoms evoked by ES of the parietal and temporal opercula, and vestibular symptoms (like the loss of ownership of the body) evoked following stimulation of the posterior insula and parietal operculum, were also induced in our study. Conclusions The insula and opercula perform various and complicated functions. The posterior insula and parietal operculum could play important roles in body-ownership symptoms. The complicated visual phenomena were partially related to the temporal operculum.

All available Danish Ephippiochthonius Beier, 1930 material was examined in this study to investigate if some specimens conform to E. kewiGabbutt, 1966, a species previously not reported from Denmark. Specimens were sorted into four groups by number of microsetae (0–3) present along the posterior border of the cephalothorax. The distribution of each group was mapped and related to recorded habitat, chaetotaxy of genital opercula, number of preocular microsetae and colouration of the cephalothorax. It was possible to assign most specimens of the four groups to two taxa conforming to E. kewi and E. tetrachelatus (Preyssler, 1790), thus both species are members of the Danish fauna. The grey-brown and strictly coastal E. kewi inhabits sheltered coasts throughout Denmark, while the yellow-brown E. tetrachelatus shows a distinct south-eastern distribution and is found at both inland and coastal sites. Chaetotaxy of the genital opercula did not differ between females of the two species, but for males it was found that E. tetrachelatus has a statistically significant higher proportion of specimens with 11 rather than 10 setae on the anterior genital operculum compared to E. kewi. The most frequent configuration of preocular microsetae in both species is two on each side, but E. kewi has significantly fewer (average a lower mean of microsetae) compared to E. tetrachelatus. The variation in chaetotaxy of the cephalothorax is limited in each species in those regions where species distributions do not overlap. But in regions with overlapping distributions, like south-eastern Denmark, some populations exhibited a higher variability in chaetotaxy which could be due to local hybridisation events. These assumed hybrids are grey-brown as E. kewi, but possess the habitat preferences of E. tetrachelatus which may explain why they are not strictly coastal, but usually found near the coast. Ephippiochthonius tetrachelatus is frequently introduced from abroad, resulting in establishment of at least temporary populations in garden centres and botanical gardens. A limited number of Ephippiochthonius specimens from Sweden were also examined and it appears that both species are present in this material as well.

Brama japonica Hilgendorf, 1878 “Reineta” es una especie íctica migratoria que vive en la zona oceánica-pelágica del océano Pacífico. Entre el mes de agosto y septiembre del 2011, 51 especímenes de B. japonica fueron obtenidos en el Terminal Pesquero de Chorrillos, Lima-Perú para la evaluación de: (1) índices ecológicos de la fauna componente metazoa parasitaria de B. japonica, y 2) agregación y selectividad de los ectoparásitos y endoparásitos más prevalente de B. japonica. Los parásitos fueron recolectados y censados usando protocolos estandarizados. El copépodo ectoparásito Hatschekia conifera Yamaguti, 1939 presentó la mayor P (prevalencia), IM (Intensidad Media), AMN (Abundancia media numérica) y IEN (Importancia Específica Numérica). En cambio, el endoparásito Hepatoxylon trichiuri (Holten,1802) Dollfus, 1942 presentó los más altos valores de AMV (abundancia media volumétrica) y IEV (Importancia específica volumétrica). En H. conifera, H. trichiuri y Koellikeria filicollis (Rudolphi, 1819) Cobbold, 1860, los índices de agregación mostraron una distribución agregada. En relación a las secciones branquiales, se observó que H. conifera el Índice de Dispersión (ID) y el Índice de Morisita (I ) presentaron una mayor agregación en la sección medial. Con relación a la AMN de M H. conifera, prefirió el II, I y III arco branquial y la sección medial. En H. trichiuri, se notó para ID e I que la distribución de agregación según localización en el 70% fue agregada y en un 30% M fue uniforme. Se observó mayormente una selectividad de H. trichiuri al mesenterio, intestino, cavidad bucofaríngea y opérculo. La longitud total y el Peso de B. japonica no se observó correlacionada con los índices parasitológicos de H. conifera, H. trichiuri y K. filicollis. Solo se vio una asociación entre la AMN de H. conifera y el sexo de B. japonica. El K (factor de n condición relativo) no se encontró relacionado con la abundancia de ninguno de los parásitos más prevalentes. Solo se vio una relación positiva entre el Índice Gonadosomático (IGS) y H. conifera. En el caso del componente comunitario, se notó valores altos de dominancia parasitaria según Simpson y Berger-Parker, e índices bajos de homogeneidad según Shannon, Brillouin y Equitabilidad. Los valores de Chao-1 nos muestran que en el componente comunitario se requiere incrementar el tamaño de la muestra. Se observó una asociación entre H. conifera versus H. trichiuri, y entre K. filicollis y Contracaecum sp.

Coralliozetus clausus, a new species of chaenopsid blenny, endemic to Isla del Coco, Costa Rica, is described. This small species, not exceeding 15 mm SL, is a short-bodied member of the genus along with Coralliozetus cardonae (Caribbean), Coralliozetus angelicus, and Coralliozetus springeri (both eastern Pacific). It differs from its closest relative, C. springeri, known from mainland waters from Costa Rica to Ecuador, in having a single tiny supraorbital cirrus and dark dots on the operculum and branchiostegal membrane of males while C. springeri has paired supraorbital cirri (one of which is substantial in size) and no dots on the operculum. Although two other species of Coralliozetus have been reported from Isla del Coco, this appears to be only member of the genus present on the island. It is the second chaenopsid endemic to Isla del Coco and brings the number of cryptobenthic fishes endemic to Isla del Coco to twelve.

The caligid parasite Caligus coryphaenae has been reported in several marine fishes from Japan. In this study, a total of 223 wild yellowtail (Seriola quinqueradiata) were collected from Kagoshima fish market, separated into three groups according to total length (TL 50 cm, TL: 50-70 cm, and TL 70 cm), and examined for C. coryphaenae infection. A total of 518 specimens of C. coryphaenae were isolated giving an overall prevalence of infection and mean intensity of 24.2% and 4.7 ± 3.5, respectively. Body surface, fins and operculum of hosts TL 50 cm were recorded as preferred sites for the attachment of C. coryphaenae. Of female specimens, 56.7% bore egg strings with various egg string lengths (7.1 ± 1.2 mm), carrying from 98 to 140 eggs (0.06 ± 0.005 mm in length) per each string. To our knowledge, this is the first report of C. coryphaenae infection from wild yellowtail in Japanese waters and globally. This parasite has not been reported in yellowtail culture to date, but the finding on wild specimens of yellowtail means that it poses a risk to their culture.

With the advancement of technology and the development of agriculture, the use of pesticides in this industry has also increased. The aim of this study was to investigate the effects of Abamectin toxin on survival and intestinal tissue of Caspian Roach as one of the valuable species in the Caspian Sea. For this purpose, 126 fingerlings fish were exposed to a different level of Abamectin for 96 h. Data analyzed showed that there was a significant correlation between fish mortality rate and Abamectin concentrations. Histological assays showed some typical tissue damages such as vaculation, necrosis, bleeding, epithelial degeneration, the intestinal villi destruction, deformation, and destruction of epithelial cells. Moreover, some clinical signs occurred like increasing operculum movement, swimming near the water surface, anxiety, and death with open mouth. The results of the present study showed that Abamectin can have toxicity effects on Caspian roach, also to sub-lethal concentrations, leading to several tissue damages and reduced survival rate of fish.

The adults and larvae of some groups in the coleopteran family Carabidae are known to prey on snails (Mollusca: Gastropoda). Most species of the carabid tribe Licinini are believed to feed on live snails. However, the snail-eating behavior of only a few species has been studied. Whether adults of the licinine genus Badister can prey on live snails was tested by providing 155 live snails of 20 species (eleven terrestrial and nine aquatic species) to adults of Badister pictus Bates, 1873, and observing their behavior under laboratory conditions. Six of the 20 snail species have an operculum that can close the aperture of the shell. Each B. pictus adult attacked all of the snails provided. Badister pictus successfully preyed on ten terrestrial and six aquatic snail species. These beetles used their strikingly asymmetrical mandibles to break the dextral shells along the dorsal part of the whorls from the outer lip of the aperture towards the apex, allowing subsequent consumption of the soft bodies. However, 41.9% of snails could not be eaten by B. pictus adults. The rate of predation success by B. pictus decreased with increasing shell size and thickness of snails. In addition, the presence of an operculum decreased the rate of predation success by B. pictus. The results show that the shell size, thickness, and operculum of some snail species could play important roles in preventing B. pictus mandibles from breaking the shells. Therefore, Badister beetles may exert selective pressure on the evolution of defensive shell structures in small-sized snails.

We identified Myxobolus anatolicus Pekmezci, Yardimci, Yilmaz & Polat, 2014 and 4 novel Myxobolus species from the Anatolian khramulya Capoeta tinca (Cyprinidae) in northern Turkey based on morphology, histology, and phylogenetic analysis. M. karaeri sp. nov. plasmodia were observed in the skin doublets between fin rays, the surfaces of the operculum, the gill arch membrane, and in the skin of the fin base. M. samsunensis sp. nov. plasmodia were observed in epithelial tissue inside and on the surface and midline of the gill filaments. M. cakmaki sp. nov. presented as a typical vascular species, which develops in large plasmodia at the end of the gill filaments. The chondrophilic M. ekingeni sp. nov. was detected by histology inside the cartilaginous gill arch and the cartilaginous gill rays of the filaments. Phylogenetic analysis of small subunit ribosomal DNA sequences revealed that M. karaeri sp. nov. and M. samsunensis sp. nov. were clustered with Myxobolus species that infect gills, scales, and fins of cyprinids. M. cakmaki sp. nov. grouped with Myxobolus species that exclusively infect the gills of cyprinids. No molecular data were available for M. ekingeni sp. nov.

Describe a new species of didymozoid digenean Neonematobothrium Yamaguti, 1965 from the operculum of the scombrid fish, Euthynnus alletteratus (Rafinesque, 1810), in the Southwest Atlantic Ocean off Brazil. Thirty-four specimens of E. alletteratus were collected in the coastal zone of the state of Rio de Janeiro and obtained from local fishermen between 2006 and 2018 in the municipal market of Sao Pedro in Niteroi, Brazil. The parasites were fixed in AFA (93% ethanol 70%, 5% formaldehyde, 2% glacial acetic acid) without pressure, stained with Langeron alcoholic acid carmine, dehydrated in an alcohol series, cleared in beachwood creosote or clove oil and mounted in Canada balsam as permanent slides. Neonematobothrium annakohnae n. sp. is a member of the genus based on a combination of the following characteristics: body free, uncapsulated; body long and dorsoventrally flattened; esophagus surrounded by gland cells; ovary and vitellarium single, long, narrow and unbranched in the anterior and posterior halves of the body, respectively; uterus with three loops; and site of infection in subcutaneous tissue of scombrid fish. The new species differs from the two recognized species of the genus mainly by the size of the body, which is much larger, the shape of the genital pore, which is differentiated in a structure similar to a small sucker and by esophagus without diverticula. Neonematobothrium annakohnae n. sp. parasite of E. alletteratus from the Southwest Atlantic Ocean, described herein, represents the third species of Didymozoidae belonging to the genus Neonematobothrium. The two known species Neonematobothrium kawakawa Yamaguti, 1965 and Neonematobothrium dorsale Yamaguti, 1970 were described from fish belonging to the same genus of the host from Pacific Ocean. The diagnosis of the genus is enlarged to “esophagus with or without diverticula”, to fill the characteristics presented by the new species. The description of N. annakohnae n. sp. demonstrates the need to expand the studies of these interesting and intriguing group of parasites, due to the fact that number of known didymozoids taxa in the Atlantic Ocean is far from representing the real situation.

The molluscan class Gastropoda includes over 5,000 parasitic species whose evolutionary origins remain poorly understood. Marine snails of the genus Caledoniella (Caledoniellidae) are obligate parasites that live on the abdominal surface of the gonodactylid mantis shrimps. They have highly modified morphological characteristics specialized to the ectoparasitic lifestyle that make it difficult to infer their close relatives, thereby posing a question about their current systematic position in the superfamily Vanikoroidea. In the present study, we performed molecular phylogenetic analyses using three nuclear and three mitochondrial gene sequences to unveil the phylogenetic position of these enigmatic snails. The resulting trees recovered Caledoniella in the superfamily Truncatelloidea and within a subclade of commensal species that live on the burrow wall of marine benthic invertebrates. More specifically, Caledoniella formed the sister clade to a commensal snail species living in mantis-shrimp burrows and they collectively were sister to Sigaretornus planus (formerly in the family Tornidae or Vitrinellidae), a commensal living in echiuran burrows. This topology suggests that the species of Caledoniella achieved their ectoparasitic mode of life through the following evolutionary pathway: (1) invasion into the burrows of benthic invertebrates, (2) specialization to mantis shrimps, and (3) colonization of the host body surface from the host burrow wall with the evolution of the parasitic nature. The final step is likely to have been accompanied by the acquisition of a sucker on the metapodium, the loss of the radula and operculum, and the formation of monogamous pair bonds. The present molecular phylogeny also suggested parallel evolution of planispiral shells in a subclade of Truncatelloidea and enabled us to newly redefine the families Caledoniellidae, Elachisinidae, Teinostomatidae, Tornidae and Vitrinellidae.

Paratanaisia bragai is a trematode that reaches sexual maturity in the kidney collecting ducts of domestic and wild birds, while the gastropods Subulina octona and Leptinaria unilamellata serve as its intermediate hosts. The morphology of P. bragai eggs is described here for the first time, using light, scanning and transmission electron microscopy. Embryonic eggs, obtained from adult worms collected from naturally infected definitive hosts, appeared elliptical, with an evident operculum, by all three microscopic techniques employed. Scanning electron microscopy revealed that the abopercular region presents a prominent U-shaped knob, which stands out from the egg surface. The thickness of the eggs, measured from ultrathin sections, were 0.34 ± 0.06 µm (0.29–0.50) at the ends and 0.31 ± 0.05 µm (0.24–0.36) in the middle region. The internal shell layer was more electron-dense and thinner than the middle layer, which comprised nearly the entire shell, while the external layer was less electron-dense and thinner than the internal layer. Rupture of the eggs, by the coverslip pressure, revealed the miracidia of P. bragai that was characterized by light and transmission electron microscopy.

One of the most thoroughly studied marine snails in the world is the North Atlantic periwinkle Littorina littorea. In 2013, Buckland-Nicks et al. reported upon an “extensive community of organisms” living “inside” L. littorea in Nova Scotia, Canada. Conflicting with this report is a vast body of research on this snail since the mid-nineteenth century that has never identified the presence of such a taxonomically diverse endosymbiotic community, with the exception of a well-known assemblage of parasitic digenean trematodes that utilize the snail as a first-intermediate host. The absence of prior reports of a non-parasitic endosymbiotic community, and our own long-term observations, inspired us to study the biological community associated with L. littorea in two locations (Nova Scotia and Connecticut). We were unable to verify the endosymbiotic nature of any of the species (other than trematodes) noted by Buckland-Nicks et al. (Can J Zool 91:293–301, 2013) associated with L. littorea. Instead, we identified three likely sources of associated taxa reported by Buckland-Nicks et al. (Can J Zool 91:293–301, 2013) and by us: species were (1) ingested and defecated alive; (2) attached to the mucous-covered foot and drawn into the mantle cavity when the snail closed its operculum; and/or (3) associated with shell surface cracks and crevices, including within encrusting algae. We could not find any evidence that L. littorea hosts a diverse community of endosymbionts. Instead, we argue that the organisms interpreted as members of an endosymbiotic community by Buckland-Nicks et al. are instead free-living taxa that are transiently associated with the snails.

A new fish species, Stolephorus tamilensis sp. nov., is described from the East coast of India. The major distinguishing characters are 5–6 small needle-like pre-pelvic scutes on belly; maxilla tip pointed, reaching to border of operculum, concave and indented in the preoperculum; 25–28 gill rakers on lower lobe of the first branchial arch; dorsal fin without spine; 17–19 anal-fin rays. Moreover, S. tamilensis sp. nov. present higher average genetic divergence values at mitochondrial cytochrome c oxidase subunit I and 16S rDNA loci in comparison with congeners. Also, nucleotide diagnostic characters exclusive to S. tamilensis are identified. Neighbor-joining analysis revealed close relation between S. tamilensis and S. andhraensis.

Parapachymorpha is one of eight genera within the tribe Medaurini of subfamily Clitumninae (Phasmatidae). It was established by Brunner von Wattenwyl (1893), with the type species Parapachymorpha nigra by subsequent designation of Kirby (1904), from Myanmar. Species of this genus are widely distributed in oriental tropics (Laos, China, Thailand, Myanmar, Vietnam and Cambodia), with only 11 known species in the world (Brock et al. 2018, Ho 2017). Species of the genus Parapachymorpha can be recognized by following characters (Brunner von Wattenwyl 1893;1907, Henmemann & Conle 2008, Ho 2017): 1) body robust in female and slender in male with long leg in relation to the length; 2) body surface of female granulose or spinose; 3) mesonotum of female more and less expanded posteriorly; 4) abdominal tergites lacking expanded prostero–lateral angles in both sexes; 5) laminal supraanalis undeveloped in female; 6) semi–tergite of male irregularly rectangular, with an additional finger­–like ventro–apical appendix on the lower margin and reduced or absent; 7) egg capsule oval to oblong and covered with a raised net–like structure in lateral view; 8) micropylar plate oval; 9) operculum concave or convex. In the present study, we describe additional species, Parapachymorpha minuta sp. nov. from Laos, with photographs of both sexes of adults and egg.

A new species of the cosmetid harvestman genus Taito Kury & Barros 2014 is described from the Área de Conservación Privada (ACP) Panguana, Peruvian Amazonia, which extends the distribution range of the genus to the south-west. The herein described species Taito adrik sp. nov. differs from all other known species of the genus by the distinct shape of the equuleus, the armature of leg IV in males, and the structure of male genitalia, in combination with features of the chelicerae and the anal operculum. In addition, COI barcodes of the new species are provided.

Many members of the Copepod family Lernaeopodidae are well-known parasites of gadids. This study reports on the occurrence of a lernaeopodid infestation of wild-sourced Gadus morhua sampled from separate inshore (Gilbert Bay, NL) and offshore (Virgin Rocks, NL) populations from Newfoundland, Canada. The majority of the parasites were observed to be associated with the buccal cavity, gill filaments, gill arch, and occasionally near the outer edge of the operculum. Anatomical analysis and detailed redescriptions of the parasite’s functional anatomy (mouth parts, antennae, and bulla complex) using high-resolution SEM indicated that the parasite was most likely of the genus Clavella. New morphological details of the second antennae ornamentation, first maxillae, bulla complex, and the oral cone are provided and discussed with regard to their potential in taxonomic applications.

The AEFishBIT tri-axial accelerometer was externally attached to the operculum to assess the divergent activity and respiratory patterns of two marine farmed fish, the gilthead sea bream (Sparus aurata) and European sea bass (Dicentrarchus labrax). Analysis of raw data from exercised fish highlighted the large amplitude of operculum aperture and body tail movements in European sea bass, which were overall more stable at low-medium exercise intensity levels. Cosinor analysis in free-swimming fish (on-board data processing) highlighted a pronounced daily rhythmicity of locomotor activity and respiratory frequency in both gilthead sea bream and European sea bass. Acrophases of activity and respiration were coupled in gilthead sea bream, acting feeding time (once daily at 11:00 h) as a main synchronizing factor. By contrast, locomotor activity and respiratory frequency were out of phase in European sea bass with activity acrophase on early morning and respiration acrophase on the afternoon. The daily range of activity and respiration variation was also higher in European sea bass, probably as part of the adaptation of this fish species to act as a fast swimming predator. In any case, lower locomotor activity and enhanced respiration were associated with larger body weight in both fish species. This agrees with the notion that selection for fast growth in farming conditions is accompanied by a lower activity profile, which may favor an efficient feed conversion for growth purposes. Therefore, the use of behavioral monitoring is becoming a reliable and large-scale promising tool for selecting more efficient farmed fish, allowing researchers and farmers to establish stricter criteria of welfare for more sustainable and ethical fish production., European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No. 652831 (AQUAEXCEL2020, Aquaculture infrastructures for excellence in European fish research towards 2020)., ProID2017010062, from Canarian Agency for Research, Innovation and Information Society (Gobierno de Canarias), co-funded with European Structural and Investment Funds (2014-2020), FICASES, Fish Cage Sensor System (TEC2017-89403-C2-2-R) from Spanish Ministry of Economy, Industry and Competitiveness, co-funded with European Regional Development Funds (2014-2020).

The reef-building sedentary polychaete, Sabellaria alveolata, is well known for its specialized anterior end, the operculum, which is exposed to the environment during vital activities, such as feeding or as it seals its tube when the animal withdraws. This region represents the most important sensory structure in Sabellariidae. It comprises two lobes, tentacular filaments, protective chaetae (paleae), a median organ, and a median ridge, and bears various pigmented spots. Worms swiftly withdraw into tubes triggered by abrupt light change (shadow reflex). We suspected that the pigmented spots were photoreceptive and responsible for the shadow response. To test this hypothesis, the median organ and median ridge of S. alveolata were investigated by applying light microscopy, confocal laser scanning microscopy, scanning, and transmission electron microscopy. Besides unciliated supportive cells, these organs consist of numerous multiciliated and glandular cells on their ventral surfaces. The multiciliated cells are of two types: epidermal supportive and receptor cells. The median organ is innervated directly from the brain by two longitudinal basiepithelial nerves. The presence of multiciliated cells and mucocytes suggests that the organ is sensory, involved in both feeding and tube-building behavior. Furthermore, we found two pairs of eyespots on the lateral posterior part of the median ridge, situated close to the neurite bundles anterior to the brain. These eyes are simple in structure and resemble larval-type eyes. They are composed of only two cells each, one rhabdomeric photoreceptor cell and one pigmented supportive cell. The pigmented eyes on the median ridge are clearly involved in photoreception and very likely involved in shadow reflex.

Gastropoda is a large and diverse group of the Mollusca found almost ubiquitously throughout freshwater, terrestrial, and marine habitats. Marine gastropods often support large commercially important fisheries, many of which are facing concerns over sustainability as landings have increased and populations have dwindled over recent decades. For effective fishery management, the inclusion of an age estimation technique is vital to understand growth rates and population structures to feed into analytical stock assessments. Unlike many bivalve species, gastropods are often difficult to age, especially those which exhibit planispiral coiling of their shells, as no single growth axis can be easily uncovered via sectioning. This review covers a range of techniques that can be used to estimate age and growth rates for many marine gastropod species. Although there is no universal aging technique to cover all species, individual techniques have varying success levels for different species groups.

Background Eggs have epidemiological and taxonomic importance in the subfamily Triatominae, which contains Chagas disease vectors. The metric properties (size and shape) of eggs are useful for distinguishing between close species, or different geographical populations of the same species. Methods We examined the effects of egg viability on its metric properties, and the possible consequences on species recognition. Four species were considered: Panstrongylus chinai, P. howardi and Triatoma carrioni (tribe Triatomini), and Rhodnius ecuadoriensis (tribe Rhodniini). Digitization was performed on pictures taken when the viability of the egg could not clearly be predicted by visual inspection. We then followed development to separate viable from non-viable eggs, and the metric changes associated with viability status of the eggs were tested for species discrimination (interspecific difference). Results The shape of the complete contour of the egg provided satisfactory species classification (95% of correct assignments, on average), with improved scores (98%) when discarding non-viable eggs from the comparisons. Using only non-viable eggs, the scores dropped to 90%. The morphometric differences between viable and non-viable eggs were also explored (intraspecific comparison). A constant metric change observed was a larger variance of size and shape in non-viable eggs. For all species, larger eggs, or eggs with larger operculum, were more frequently non-viable. However, these differences did not allow for an accurate prediction regarding egg viability. Conclusions The strong taxonomic signal present in egg morphology was affected by the level of viability of the eggs. The metric properties as modified in non-viable eggs presented some general trends which could suggest the existence of an optimum phenotype for size and for shape. Globally, viable eggs tended to have intermediate or small sizes, and presented a less globular shape in the Triatomini, or a relatively wider neck in Rhodnius ecuadoriensis. Electronic supplementary material The online version of this article (10.1186/s13071-018-3104-1) contains supplementary material, which is available to authorized users.

Made available in DSpace on 2019-10-06T15:21:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01. Added 1 bitstream(s) on 2019-10-09T18:34:46Z : No. of bitstreams: 1 S0102-09352018000501565.pdf: 778835 bytes, checksum: 6c5b5c029b202cb10282793b76ca53d9 (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) As deformidades esqueléticas são problemas frequentes em populações de peixes cultivados devido, principalmente, a condições abióticas desfavoráveis, nutrição inapropriada e fatores genéticos. Estas podem causar natação errática, diminuição do índice de conversão, do crescimento e do valor no mercado. O objetivo deste relato de caso foi apresentar a ocorrência de deformidades em cobias e garoupas juvenis provenientes de uma fazenda marinha em sistema offshore, em Ilhabela, São Paulo, Brasil. Nove cobias e sete garoupas juvenis, que apresentavam deformidades, foram sujeitos à eutanásia e fixados em formol a 10%. Os espécimes foram registrados, processados e corados com Alcian Blue (AB) e Alizarin Red-S (ARS) para visualização de tecido cartilaginoso e ósseo, respectivamente. Os peixes foram eviscerados para o exame radiográfico. As deformidades observadas em cobia foram: atrofia do opérculo, desorganização das lamelas branquiais, deformidade do maxilar inferior, cifose e escoliose. As garoupas apresentaram deformidade do maxilar inferior e síndrome de Saddleback. Os peixes deste relato de caso estiveram sob manejo deficiente, alimentados com ração comercial para peixes herbívoros de água doce e sardinhas cozinhadas, alta consanguinidade e ausência de profissionais adequadamente treinados para o manejo dessas espécies. A soma desses fatores influenciou diretamente na aparição dessas deformidades, precisando ser controlados para minimizar a incidência de malformações que tenham impacto econômico para os produtores. Skeletal deformities are frequent problems in cultured fish populations due mainly to unfavorable abiotic conditions, inappropriate nutrition, and genetic factors. These may cause erratic swimming, decrease of conversion rate, growth, and market value. The aim of this case report was to present the occurrence of deformities in juvenile cobia and groupers from an offshore marine farm in Ilhabela, São Paulo, Brazil. Nine cobias and seven juvenile groupers, that presented deformities, were euthanized and fixed in 10% formaldehyde. They were tagged, processed, and stained with Alcian Blue (AB) and Alizarin Red-S (ARS) for visualization of cartilage and bone tissue, respectively. After evisceration, radiographic examination was performed. The deformities observed in cobia were atrophy of the operculum, disorganization of the gill lamellae, deformity of the lower jaw, kyphosis, and scoliosis. Groupers presented lower jaw deformity and saddleback syndrome. The farm studied in this case report had poor management standards, fed commercial feed for freshwater herbivorous fish and cooked sardines, high inbreeding and absence of adequately trained professionals to manage these species. The sum of these factors must have directly influenced the appearance of these deformities. It is necessary to control this situation to minimize the incidence of malformations that have economic impacts to farmers. Universidade Estadual Paulista (UNESP) - Caunesp Pontifícia Universidade Católica do Paraná Universidade Estadual Paulista (UNESP) - Caunesp

A total of 30 specimens of fish cobia Rachycentron canadum (Total Length = 45–120 cm, Weight = 3.0–25 kg) were stocked at the density of 1 kg/m3 in the polythene lined earthen pond. After 3 months of stocking, fish cobia was found with infection of ectoparasites. Then fishes were sampled at fortnight interval to find the percentage distribution of ectoparasites in different parts of the body for a year and also any pathological symptoms. Identification of the parasite was made through light and electron microscopies. The parasite was identified as Argulus quadristriatus Devaraj and Ameer Hamsa, 1977 (Crustacea: Branchiura: Argulidae) commonly called as fish lice. The maximum distribution of pathogenic argulid was observed on the head and operculum of cobia and was found high in summer months from April to June. Pathological symptoms were observed on cobia as erratic swimming, rubbing against substrate in the pond and lesions of epithelial tissues on the infected regions. It must be due to continuous rupturing and feeding of argulids on the skin of cobia using its powerful antennae. Scanning electron micrographs revealed some important morphological features of A. quadristriatus. This is a first report of A. quadristriatus infection on cobia reared in a land-based pond ecosystem.

Calculating age and growth rate for the commercially important whelk, Buccinum undatum in the aid of fishery management has historically been undertaken using growth rings on the organic operculum. This is difficult due to their poor readability and confusion between two different sets of growth lines present. Recent work presented the calcium carbonate statolith as an alternative for age determination of B. undatum. Here we compare the use of statoliths and opercula, comparing their readability and creating growth curves for three distinct populations across the United Kingdom. Using these data, we also test the most appropriate growth equation to model this species. Lastly, we use oxygen isotope analysis of the shells to assign accurate ages to several individuals from each site. These data were used to test the accuracy of statolith and operculum ages. Statoliths, whilst more time consuming to process have improved clarity and accuracy compared with the opercula. This improved readability has highlighted that a Gompertz growth function should be used for populations of this species, when in past studies, von Bertalanffy is often used. Statoliths are a viable improvement to opercula when assessing B. undatum in the context of fishery monitoring and management.

Specimens belonging to the family Blenniidae were collected in a fishery resource investigation from the coastal waters of Xisha Islands and Hainan Island, South China Sea in 2016. Combining morphological results with sequence analysis, we identified one specimen as Xiphasia matsubarai Okada & Suzuki, 1952. This represents a new record in the South China Sea. In morphology, the specimen has the following traits: body elongated, eel-like or ribbon-like in shape; flanks medium flat; the head small bluntly rounded anteriorly and without a moustache; eyes is slightly smaller, on upper lateral position of head, which is about equal to 1/5 of the length of the head; body without scales, lateral line has been degraded; both sides of the upper and lower jaws with a canine; gill is opening at the top of the pectoral fin base, approximately equal to the length of eye diameter. Dorsal fin XI, 96; pectoral fin 10; anal fin II, 95. Head and body grey-brown, including 26 dark grey-brown bands; abdomen and lower operculum yellowish grey and colour lighter; and dorsal base long with dark grey. Origin of dorsal is located over the anterior margin of pupil; black blotch on dorsal fin between 8th and 10th dorsal spine; anal and caudal fins dark grey, pectoral and ventral fins pale yellow. Sequence analysis of cytochrome oxidase subunit I gene (COI) strongly supports the identity of the specimen as X. matsubarai.

Tetracotyle wayanadensis n. sp. (Digenea, Strigeidae) infecting different organs of six species of freshwater fishes, Haludaria fasciata (eye, buccal cavity), Amblypharyngodon melettinus (eye, buccal cavity), Aplochelus lineatus (operculum, heart, mesenteries), Pethia conchonius (brain), Parambassis thomassi (muscles, mesenteries) and Lepidocephalus thermali (mesenteries) collected from water bodies in the Wayanad region of the Western Ghats is described and illustrated. Tetracotyle wayanadensis n. sp. is new to the genus and is separated from its congeners on the basis of differences in morphology and morphometry. The present paper also describes the prevalence, intensity, mean abundance and sites of infection of the parasite in each host. The prevalence of infection of T. wayanadensis n. sp. in Haludaria fasciata is 7.5%, intensity of infection is 2.66 and mean abundance is 0.2; in Amblypharyngodon melettinus 10%, 6 and 0.6; in Aplochelus lineatus 12.2%, 6.2 and 0.76; in Pethia conchonius 7.14%, 5 and 0.36; in Parambassis thomassi 100%, 2 and 2; in Lepidocephalus thermali 10%, 2 and 0.2 respectively.

The common carp Cyprinus carpio is one of the most widely-distributed freshwater fishes in the world. Due to its value for conservation and fisheries in several native/translocated areas of distribution and its detrimental effects on the aquatic ecosystem in most invasive areas, robust age-based population dynamics models are required for successful management of this species. The present study provides a global review of age determination in carp, including a historical account of ageing methods, an assessment of the relative utility of ageing structures, and an evaluation of precision and accuracy (i.e. validation) of age estimates. Historically, scales were by far the most widely-employed structure, followed by the operculum, otolith, dorsal spine, vertebra and fin ray. However, in countries where carp is categorised as ‘high risk’ of impact, use of alternative structures to the scale was predominant. Causal criteria analysis showed scales and opercula to provide inconsistent evidence for successful annulus identification/counting, whereas consistent evidence was found for otoliths, dorsal spines, vertebrae and (pectoral) fin rays. Precision was always above reference thresholds for scales, whereas for otoliths, dorsal spines and fin rays was in several cases below. Accuracy was addressed sporadically and mostly in high-risk countries. It is suggested that dorsal spines or pectoral fin rays should be used in lieu of scales as non-lethal ageing structures, and otoliths (or vertebrae, pending more research) otherwise, and that validation should always be attempted as part of the set-up of more appropriate ageing protocols and use of correct terminology.

This paper reports a case of natural co-infection of Tilapia Lake Virus (TiLV) and Aeromonas veronii in a Malaysian red hybrid tilapia (Oreochromis niloticus × O. mossambicus) farm. In May 2017, a tilapia farm operator reported a mass mortality among cultured red hybrid tilapia juveniles, approximately 45 days after introduction into earthen ponds. Affected fish showed lethargy, loss of appetite, swim near the pond edge, pale and isolated from schooling group. There were skin redness and haemorrhages, particularly at the operculum area and at the base of dorsal, caudal and anal fins. Histopathological examinations revealed swollen hepatocytes, haemorrhagic spleens and perivascular cuffing consisted of mononuclear cells in the brains. PCR and sequence analyses confirmed the presence of TiLV and A. veronii in the diseased fish. Phylogenetic tree revealed that Malaysian's TiLV strain was more closely related with the virus isolated in Israel than in Egypt or Thailand, while Malaysian's A. veronii strain 5L was closely related with strains from China. TiLV infection is a significant threat to global tilapia industry. However, synergistic co-infection of TiLV and other bacterial might aggravate the problem.

A new freshwater goby, Rhinogobius immaculatus sp. nov. , is described here from the Qiantang River in China. It is distinguished from all congeners by the following combination of characters: second dorsal-fin rays I, 7–9; anal-fin rays I, 6–8; pectoral-fin rays 14–15; longitudinal scales 29–31; transverse scales 7–9; predorsal scales 2–5; vertebrae 27 (rarely 28); preopercular canal absent or with two pores; a red oblique stripe below eye in males; branchiostegal membrane mostly reddish-orange, with 3–6 irregular discrete or connected red blotches on posterior branchiostegal membrane and lower operculum in males; caudal-fin base with a median black spot; and no black blotch on anterior part of first dorsal fin in males.

The present study shows that permanent melanophore spot patterns in Atlantic salmon Salmo salar make it possible to use images of the operculum to keep track of individual fish over extended periods of their life history. Post-smolt S. salar (n = 246) were initially photographed at an average mass of 98 g and again 10 months later after rearing in a sea cage, at an average mass of 3088 g. Spots that were present initially remained and were the most overt (largest) 10 months later, while new and less overt spots had developed. Visual recognition of spot size and position showed that fish with at least four initial spots were relatively easy to identify, while identifying fish with less than four spots could be challenging. An automatic image analysis method was developed and shows potential for fast match processing of large numbers of fish. The current findings promote visual recognition of opercular spots as a welfare-friendly alternative to tagging in experiments involving salmonid fishes.

The veliconcha larva of the predatory gastropod Conus spurius Gmelin, 1791 is described and for the first time illustrated based on material from Sanibel Island, Florida. Hatchling veliconchas were 1470–1570 μm (mean = 1530) long, with first protoconch whorl maximum diameter 670–740 μm (mean = 710), and estimated egg diameter 570 μm. Veliconchas can swim for a few minutes to a few hours before settling. They have well-developed paired velar lobes each 600–700 μm in length, an extensible foot with a distinct metapodium separated from the remainder of the foot by a transverse fold, and operculum. Several early life history traits of C. spurius, particularly hatching as large veliconcha larvae with predominantly lecithotrophic, nearly non-planktonic development, closely resemble those of a well-defined clade of Conus Linnaeus, 1758 species that prey on other gastropods. They contrast with the majority of species in this hyperdiverse genus, which hatch as much smaller planktonic, obligatory planktotrophic veliger larvae. As adults they comprise a vermivorous feeding guild, preying exclusively or nearly so on polychaete annelids. Limited data suggest that C. spurius may share this trait with them but it may also prey on molluscs. Recent molecular phylogenetic trees suggest that the characters “pelagic development” and “non-pelagic development” (or nearly so