Wisner and McMillan: Review of new world hagfishes of the genus Myxine 



533 



Systematics 



Myxine circifrons Garman, 1 899 



Myxine circifrons Garman, 1899: 344 "Albatross Sta- 

 tion 3395; 7°30'36"N, 78°W; 730 fm (1,336 m) tem- 

 perature 38.5°F; bottom rocky." 



Diagnosis A 3-cusp multicusp on anterior sets of 

 cusps; five gill pouches each side; color blackish to dark 

 reddish-brown, anteriormost portion of head pale. 



Description Counts and proportions are given in 

 Tables 1-7. Body robust, slightly deeper than wide; 

 snout bluntly pointed, rostrum short, variably tri- 

 angular to bluntly rounded; cusps short, stout; ante- 

 rior multicusps bulbous at bases, the free tips about 

 equal in length to bulbous portion; tail length about 

 13% of TL, its depth about 40% of its length; VFF 

 usually well developed, but may be vestigial, rang- 

 ing in height from 1 to 12 mm, averaging about 5 

 mm; CFF high, extending around tail to about over 

 cloaca, thickened dorsally; body color dark, grayish- 

 black to reddish-brown; anterior portion of head 

 paler, often whitish to near vertical from margin of 

 face, occasionally extending into the prebranchial 

 region; barbels color of head; VFF and CFF same color 

 as body, without pale margins; GA and slime pores 

 often with narrow pale margins; total cusps 43-56; 

 total slime pores 80-102; numbers of large eggs (20 

 mm and longer) range from 15 to 18 in females of 

 435 mm TL, largest egg 28 x 7 mm. 



Distribution From near San Francisco, California, 

 to north-central Chile at depths of about 700 to 1,860 



Rostrum 



Head 

 \\\ length 



I 



I 



MoUth 



Figure 2 



(A) sketch of ventral aspect of a myxinid head, identifying 

 the terms used in the text: (B) and (C), sketches of a 3- 

 cusp and a 2-cusp multicusp, with two adjacent unicusps. 



m (Fig. 3). We find no significant differences in counts 

 or proportions throughout this extensive range of 

 about 11,000 kilometers. 



Comments Sex ratios in our material are equal off 

 southern California (n=220) but unequal near the 

 mouth of the Gulf of California fn= 136), 66% female 

 to 34% male, and Costa Rica to northern Chile (n-54), 

 59% female to 41% male. We find no hermaphrodit- 



Figure 3 



Areas of occurrence of new world species of Myxine: 1 = 

 M. circifrons, from near San Francisco, California, to 

 north-central Chile; 2 = M. hubbsi, from near San Fran- 

 cisco, California, to near Valparaiso, Chile; 3 = M. 

 hubbsoides and 4 = M. pequenoi, off south-central Chile; 

 5 = M. fernholmi, from near Valdivia, Chile to Falkland 

 Islands, S.E. Atlantic Ocean; 6 = M. dorsum and 7 = M. 

 debueni, Straits of Magellan; 8 = M. australis, principally 

 in Straits of Magellan; two collections off Chile, and one 

 near Pta. Nuevo, Argentina; 9 = M. afftnis, Straits of 

 Magellan; 10 = M. knappi, near the Falkland Islands; 11 

 = M. mccoskeri, 12 = M. robinsi, and 13 = M. mcmillanae, 

 southern Caribbean Sea; 14 = M. limosa, Davis Strait, 

 Greenland, southerly to eastern portion of the Gulf of 

 Mexico. 



