Search

A new nonparasitic lamprey, Entosphenus folletti from the Klamath River system, California, is described and illustrated. The holotype (No. NMC 75-1549) is deposited in the National Museum of Natural Sciences, Ottawa, Canada. The species, by its non-functional intestinal tract, is easily separable from the two parasitic species: E. tridentatus and E. minimus. It differs from the nonparasitic E. lethophagus, of the same river system, by having (1) a larger disc: 6.6–7.8% of total length (4.1–6.1% in E. lethophagus), (2) a stronger dentition and a higher number of inner lateral cusps: 2-3-3-2 against 2-2-2-2, (3) a median velar tentacle that is well developed and the same size as the lateral, while in E. lethophagus it is greatly reduced in size in comparison with lateral tentacles, and (4) a darker body coloration and heavily pigmented second dorsal fin. In ammocoetes of E. folletti the bulb of the tongue precursor has a dark pigmentation that is absent in E. lethophagus. The description is based on a study of six transformed individuals and 25 ammocoetes.

Published descriptions of Okkelbergia Creaser and Hubbs, 1922 include no characteristics not found in Lampetra. Both taxa share the following generic characters: three pairs of inner lateral teeth, typically two supraoral cusps, and lack of posterial teeth. Okkelbergia is considered to be a junior subjective synonym of Lampetra Gray, 1851.

A new nonparasitic lamprey, Eudontomyzon hellenicus, from the Struma and Loúros river basins in Greece, is described and illustrated. The holotype (No. NMC 77-1773) is deposited in the National Museum of Natural Sciences, Ottawa, Canada. From all species of the same genus, E. hellenicus differs in the following characters: (1) small metamorphosed size (maximum total length (TL) 159 mm), (2) fewer trunk myomeres (52–62, averaging 57.4), (3) poorly developed lingual laminae cusps, (4) short and few (2–5) velar tentacles, and (5) extremely short urogenital papilla, even in spawning males. Furthermore, a nonfunctional intestinal tract in metamorphosed individuals of our species separates it from parasitic E. danfordi. The description is based on a study of 64 metamorphosed specimens, 13 transforming individuals and 237 ammocoetes.

At present five species of Petromyzonidae are found in the Great Lakes region. Of these, three are parasitic: Petromyzon marinus, Ichthyomyzon unicuspis, and I. castaneus; two are nonparasitic: I. fossor and Lethenteron lamottenii. It is quite possible that a nonparasitic sixth species, Lampetra aepyptera, could be found in the Lake Erie basin.Key words: lampreys, Great Lakes, keys, P. marinus, abnormality, L. lamottenii, gigantism

Among students of lamprey taxonomy, there has been agreement on the common names for the least brook lamprey and American brook lamprey, two nonparasitic species of eastern North America. However, there still is a disagreement as to their scientific names. On the basis of a critical study of original descriptions and drawings of American authors of the last century, we reached the conclusion that the length of the urogenital papilla in spawning males is a very important taxonomic character. Therefore, we propose that the name for the least brook lamprey, which has a long urogenital papilla, is Lampetra lamottenii (Lesueur); and for the American brook lamprey, with a short papilla, is Lethenteron wilderi (Gage).

A new parasitic lamprey is described from 29 metamorphosed specimens in feeding stage. The holotype (No. NMC 75-1550) is deposited in the National Museum of Natural Sciences. Ottawa, Canada. It is easily separable by its functional intestinal tract and strong dentition from the three nonparasitic species: Entosphenus folletti, E. hubbsi, and E. lethophagus. From the parasitic E. tridentatus it is distinguishable by (1) fewer myomeres, (2) greater disc length, (3) smaller eye diameter, (4) differences in dentition, and (5) differences in number and morphology of velar tentacles. From another parasitic species, E. minimus, it differs by (1) larger size, (2) greater disc length, (3) smaller eye length, (4) stronger dentition, and (5) differences in velar tentacle number.

The new term 'satellite species' is used to replace the less accurate and by now obsolete term 'paired species.' Among lamprey genera a complex of species is usually found: one parasitic or 'stem' species and one or several nonparasitic or 'satellite' species probably derived from it. Among eight genera of holarctic lampreys the interrelation between the number of parasitic (p) and satellite (s) species is as follows: Caspiomyzon, 1p and no s; Petromyzon, 1p and no s; Ichthyomyzon, 3p and 3s; Tetrapleurodon, 1p and 1s; Entosphenus, 3p and 3s; Lampetra in Europe, 1p and 2s, in North America, 1p and 3s; Eudontomyzon in Europe, 1p and 3s, in Asia, 1p and no s; Lethenteron, 1p and 5s. Thus among the six polyspecific genera of the holarctic lampreys, 12 parasitic and 20 satellite species are presently known.

Breeding tubercles in Gadus are described for the first time. Each of the three known species of Gadus displays specific peculiarities: in G. ogac, tubercles are numerous, long, and club-shaped; in G. morhua, tubercles are numerous, medium in length, and horn-shaped; and in G. macrocephalus, tubercles are few and very small. These breeding tubercles may be used for taxonomic purposes. It is probable that the tubercles may serve to maintain contact during the reproductive period.

Description is given of a female sea lamprey (Petromyzon marinus) 498 mm long, which had a true anal fin, 31 mm in length supported by about 30 cartilaginous rays. The question of the presence of an anal fin in Petromyzonidae is also discussed.

Three American eels (Anguilla rostrata) with unusually large eyes, obtained from the collections of the Museum of Zoology, University of Michigan (UMMZ 80616), are described. Two are males, 495 and 521 mm in total length, and the third, probably of the same sex, had an estimated length of 752 mm. The horizontal diameter of the eye was equal to the inter-orbital width in the smallest specimen, while in the two others it was greater. These fish, captured in 1926, came from a sample of elvers liberated into Sherman Lake, Michigan, about 35–40 years earlier.

For the present study about 300 specimens have been examined. These specimens belong to the six species of chars: C. namaycush, S. fontinalis, S. aureolus, S. oquassa, S. marstoni, and S. alpinus. Among meristic characters, the number of pyloric caeca was found to be very important. Body proportions and meristic characters, such as fin rays and vertebrae, are inadequate to properly describe a species. On the other hand, the skull bones, different teeth, and skeleton of the tail are sufficient in themselves to define a species. The pearl organs were found only in C. namaycush of both sexes. The taxonomic relation between species is as follows: C. namaycush belongs to a distinct genus; S. fontinalis represents a subgenus Baione; while the remaining chars are grouped in a subgenus Salvelinus.

The sea sturgeon, Acipenser oxyrhynchus Mitchill, occurs in the western north Atlantic Ocean from Canadian waters south to the Gulf of Mexico. Specimens taken from eastern Florida to Quebec are assigned to the typical subspecies oxyrhynchus, while 2 specimens from off Mississippi are here described as the new subspecies de sotoi. The latter differs in having a longer head, longer pectoral fins, strongly developed scutes of distinctive shape and an unusually long spleen.

Lampetra ayresii (Günther), a species of parasitic river lamprey endemic to western North America, is redescribed on the basis of material from off the Skeena River, British Columbia, to San Francisco Bay, California. A neotype is designated. Transformed specimens differ from those of the European Lampetra fluviatilis (Linnaeus) in having a larger eye, a longer prebranchial and a shorter branchial region, and possibly a lower second dorsal fin, an acute rather than an obtuse caudal fin, a higher average number of trunk myomeres, and an area of dark pigment on the caudal fin. Ammocoetes differ from those of Lampetra fluviatilis principally in having a higher number of myomeres, a dark caudal spot (which distinguishes them also from ammocoetes of Lampetra planeri (Bloch), the nonparasitic brook lamprey), and an absence of dark pigment on most parts of the head and on the precursor of the tongue. Specimens from Oregon are recorded for the first time. Specimens from Mill Creek, Tehama County, California, show that this species ascends the Sacramento River farther than previous records indicated. An annotated synonymy is included. Lampetra ayresii is indicated as distinct from Ammocoetes cibarius Girard, which is regarded as identical with Entosphenus tridentatus (Richardson). Lampetra ayresii and Lampetra fluviatilis are illustrated by a number of original drawings and photographs.

A new nonparasitic species of Petromyzonidae, Lampetra richardsoni, the western brook lamprey, from streams of British Columbia, Washington, Oregon, and possibly Alaska, is described and illustrated. This species is distinguished from Lampetra planeri (Bloch), the European brook lamprey (with which it has long been regarded as identical), by dentition, body proportions, pigmentation of the head and tail, and geographical distribution. The description is based on an examination of 275 specimens (69 transformed individuals and 206 ammocoetes).

not available

For the present macroscopic study over 1,000 female speckled trout from the Laurentide Park in Quebec have been examined. Of this number, 747 specimens received special attention. In ovaries of adult trout 3 types of eggs were found: recruitment stock (Class a), maturing eggs (Class b) and atretic eggs (Class c). In the process of maturation, the number of eggs of Class b progressively decreases due to atresia, but their diameter becomes greater. Comparisons of fecundity between different trout populations should be made only when eggs are nearly mature. The diameter of ripe eggs just previous to spawning, preserved in formalin, varied from 3.8 to 4.8 mm. There is a direct relation between the number of ripe eggs and the size of the fish: the extreme numbers of eggs were 90 and 4,800 eggs, and the extremes of fork lengths of females were 6 and 22 inches. The fecundity is greater among fish from lakes richer in food. A simplified method of determining the number of eggs in ovaries was devised. The maturity of females was determined by a 7-digit system. The colour of flesh was classified by a 6-digit system.

The present study is based on examination of six collections of fishes (about 4000 specimens) from the Hudson bay region made between 1919 and 1930. The material consisted of 45 different forms, belonging to 42 species, 34 genera and 17 families.No endemic species are known from this area. The following subspecies are described as new: Ammodytes dubius hudsonius, Gymnocanthus tricuspis hudsonius and Lycodes reticulatus hacheyi.Sixteen fresh-water and brackish-water forms collected in the Hudson bay area are the same as those that occur in the Great Lakes and St. Lawrence regions.Twenty-eight marine species are known from the region under consideration; the majority of them (22) are truly arctic forms.Two species (Gymnocanthus galeatus and Liparis cyclostigma) previously known only from the north Pacific and Bering sea are found in Hudson bay.The most important commercial fishes are principally anadromous and rarely marine.

During the 12-year period, from 1945 to 1956, 19,310 fish of 13 species were tagged in Quebec. Three types of tags were used. From 1938 to 1940, monel metal strap tags, adapted from the “cattle ear tag” were tried, but were discarded as unsatisfactory. Since 1940 two different types designed by the author have been used. Ring-shaped strap tags of monel or nickel have been found satisfactory for tagging some species such as sturgeon, channel catfish, and eel. For other fishes, such as shad, smelt, striped bass, tomcod, split ring and plate tags are more advantageous. In the case of two species of sturgeon, several fish with strap tags were recovered 10 and 11 years after liberation. The maximum distances between tagging and recovery points in Quebec tagged fishes were 892 miles for Atlantic sturgeon and 1,650 miles for shad.

The description of young ammocoetes, 19–68 mm in length, belonging to Petromyzon marinus and Entosphenus lamottenii, is given. The principal differences between species consist in the intensity and pattern of the pigmentation. For identification, in decreasing order of importance, the different sections of an ammocoete are as follows: the dorsal surface of the head and trunk, the lateral side of the head, and the tail region. Among the other characters are described the peritoneum, which is pale, unpigmented in E. lamottenii and darkly pigmented in P. marinus; and the precursor of the tongue, the dark pigmentation of which is found in 98% of E. lamottenii and only in 11% of P. marinus.

The urogenital papillae of 30 species of Holarctic lampreys were examined to determine if this structure has any taxonomic use. Total length, branchial length and papilla length were measured. A correlation between mean papilla length and mean total length of the species existed in males for parasitic species but not nonparasitic species, indicating a potential use in nonparasitic species. In nonparasitic species the most obvious differences existed in the papilla length: branchial length ratio. From the limited material available there appeared to be no geographic variation in this ratio, although there is a seasonal variation with the ratio increasing as spawning approaches. It therefore appears that urogenital papilla length has taxonomic value in male nonparasitic lampreys, provided the specimens are collected in spawning condition. The female papilla is too small to be of use.

In Fig. 4, on page 1797, the legend should read as follows: "Fig. 4. Comparison between Lethenteron matsubarai and L. japonicum from Shokotsu River, Hokkaido, Japan, (a) Head region of L. matsubarai, tag W2392, male, TL 171 mm. (b) Head region of L. japonicum, tag W2383, female, TL 172 mm. (c) Tail region of L. matsubarai, tag W2386, male, TL 150 mm. (d) Tail region of L. japonicum, tag W2383, female, TL 172 mm."

HANKS to Dr. Giuseppe Zanandrea, Istituto di Anatomia Comparata della Universita di Bologna, we received two wellpreserved samples of Italian lampreys, one of which consists chiefly of transformed individuals and the other of ammocoetes. Careful study showed these specimens to be so different in comparison with Lampetra planeri (Bloch), obtained from various European countries, that I regard them as a distinct species. This new species is named in honor of Dr. G. Zanandrea, who made several interesting biometrical and biological studies of lampreys from northern Italy (Zanandrea, 1940a, 1940b, 1947, and 1951).