534 



Fishery Bulletin 93(3). 1995 



ism in 320 specimens exceeding 350 mm TL, a mini- 

 mum length arbitrarily chosen as offering reliable 

 sex determination. 



Myxine mccoskeri new species 



Holotype SIO70-363, female, 201 mm, taken at 

 09°39'N, 78°60'W, 530-560 m, 1 October 1970. 



Paratypes SIO70-363, 2 ( 117, 170 mm), taken with 

 the holotype; SIO90-117, 1 (235 mm), 11°46'N, 

 67°05'W, 1, 100-1,174 m (formerly UMML 29269); 

 USNM 325212, 2 (170, 235 mm), 11°30'N, 72°26'W, 

 530-567 m (formerly UMML 28722); CAS 79537, 2 

 (170, 235 mm), 12°13'N, 75°50'W, depth unknown 

 (formerly UMML 29884); MCZ 48809, 2 (218, 264 

 mm), 11°35'N, 62°52'W, 512-547 m; MCZ 41634, 1 

 (254 mm), 11°35'N, 62°59'N, 439-476 m. 



Diagnosis A 3-cusp multicusp on anterior sets of 

 cusps; five gill pouches each side; VFF weakly devel- 

 oped, often nearly vestigial, 0-5 mm high; color dark 

 brown, often lighter dorsally than ventrally; a dwarf 

 species, mature at about 300 mm TL. 



Description Counts and proportions are given in 

 Tables 1-7. Body slender, slightly deeper than wide, 

 its width about 75% of its depth; tail narrow, its 

 length about 15% of TL, its depth about 33% of its 

 length. VFF usually low, ranging in height from 0-5 

 mm, average 2 mm; CFF prominent, its margins thin, 

 the internal supporting rays visible; snout rather 

 sharply pointed, rostrum elongate, bluntly pointed; 

 cusps long, slender, sharp, the bases of multicusps 

 slightly bulbous; body variably pale to medium or 

 dark brown, the head and ventral aspects anterior 

 to GA lighter than body; posterior to GA the ventral 

 aspect is notably darker toward end of tail, a pale 

 band extends dorsally to over the cloaca, the general 

 aspect being reverse countershading; VFF and CFF 

 color of body, usually without, or with faintly expressed, 

 pale margins; barbels very slightly or not at all pig- 

 mented; GA with narrow pale margins, slime pores 

 without; total slime pores 77-92; total cusps 36-48. A 

 264-mm-TL paratype (MCZ 48809) contains only four 

 large eggs, each about 18x7 mm; in addition, two other 

 females (218, 222 mm) contain four and five eggs, about 

 15x5 mm. We consider this species dwarfed because of 

 the short length of females with such large eggs. 



Etymology We name this species for John E. 

 McCosker, Director, Steinhart Aquarium, San Fran- 

 cisco, for his work on Caribbean and Panamanian 

 fishes, and for making the first specimens of this 

 species available to us. 



Distribution Known only from the southern Carib- 

 bean Sea (Fig. 3). 



Comments Shimizu (1983) reported as Myxine sp. 

 three specimens (273-320 mm TL) from off Suriname 

 at 310 m, with 3-cusp multicusps on anterior sets of 

 cusps, 38 total cusps, and 87-90 total slime pores; 

 number of gill pouches and sexual maturity not 

 stated. Color was described as "Body color white on 

 snout, gradually becoming blackish, and uniformly 

 black behind posterior half of head." The cusp and 

 slime pore counts agree well with M. mccoskeri; how- 

 ever, the white snout as described and shown in the 

 color photo from Shimizu, is whiter than those on 

 our specimens of M. mccoskeri. This feature and the 

 blackish body are more like those of M. robinsi (de- 

 scribed below); however, the latter has more total 

 cusps (56-58) and total pores (94-104). 



Myxine robinsi new species 



Holotype SIO90-149, ripe female, 475 mm TL, 

 taken at 11°37'N, 60°50'W, in a 40-ft otter trawl be- 

 tween 783 and 1281 m (formerly UMML 29270, date 

 of capture not recorded). 



Paratypes SIO90-149, 1 (510 mm) taken with the 

 holotype; USNM 325213, 1 (540 mm); 11°37'N, 

 60°59'W (formerly UMML 29877); MCZ 101239, 1 

 (460 mm), 10°03'N, 7620'W, (formerly UMML 22807), 

 675-966 fm [1,235-1,768 m]. 



Diagnosis A 3-cusp multicusp on anterior set of 

 cusps; five gill pouches each side; whitish on head 

 and continuing to first few prebranchial pores, and 

 light dorsally to about over GA; body light to me- 

 dium brown. 



Description Counts and proportions are given in 

 Tables 1-7. Body rather robust, slightly deeper than 

 wide; tail length about 13% of TL, its depth about 

 38% of its length; VFF moderately well developed, 

 3-6 mm high; CFF prominent, extending around tail 

 to about over cloacal origin, thickening dorsally; ros- 

 trum variably rounded to bluntly conical; anterior 

 unicusps long, slender, sharp, curved near tips; bases 

 of anterior multicusps slightly bulbous; color light 

 to medium brown; head whitish continuing to first 

 few prebranchial pores; a decreasingly paler area, 

 often blotchy, extends posteriorly along dorsal sur- 

 face and often laterally to near GA; slime pores and 

 GA with no or very pale margins; VFF and CFF color 

 of body, without pale margins. One female 475 mm 

 TL contains six large eggs, 29-31 mm long by 11-12 

 mm wide, arranged in a single row. 



