540 



Fishery Bulletin 93(3). 1995 



Synonymy Myxine atlanticus Regan, 1913:398 

 (Western North Atlantic, 44°27'N, 58°10'W; 120 fm; 

 counts, proportions). 



Diagnosis A 2-cusp multicusp on both the anterior 

 and posterior sets of cusps; six gill pouches each side; 

 head rather pointed, rostrum triangular, bluntly 

 pointed; color reddish-brown to dark purple; head 

 often pale; occasional ventral blotches; VFF variably 

 low to high; a narrow pale streak on dorsal midline 

 usually present. 



Description Counts and body proportions are given 

 in Tables 1-7. Body slender, nearly cylindrical; tail 

 slender, 12-17% of TL, its depth about 30% of its 

 length; VFF low, 0-4 mm (average 1.6 mm); CFF 

 prominent, thin, thickening dorsally; head pointed, 

 rostrum bluntly triangular; body color varying shades 

 of reddish-brown to blackish-purple; head only 

 slightly pale; occasional pale blotches ventrally; VFF 

 and CFF usually with pale margins; GA and slime 

 pores with prominent pale margins; a narrow pale 

 streak of variable length usually present on dorsal 

 midline; females (368-385 mm TL) contain 12 to 20 

 large eggs, 17x5 to 27x8 mm; a 385 mm female con- 

 tains 14 fully developed eggs, 16x6 to 17x8 mm, all 

 linked by anchor filaments. 



Distribution Between Davis Strait (66°N) and south 

 to Florida, between 75 and 1,006 m; one specimen 

 (383 mm TL) from Campeche Bank, Gulf of Mexico, 

 at 24°25'N, 87°38'W. 



Discussion Since its description, M. limosa has of- 

 ten been identified as M. glutinosa L. (1758) from 

 the eastern North Atlantic (ENA), but we find two 

 characters involving coloration that distinguish the 

 two. All descriptions and our findings on ENA mate- 

 rial indicate a grayish-pink color; in contrast, all our 

 western North Atlantic (WNA) material is reddish- 

 brown to blackish-purple. Girard (1858) indicated 

 reddish to dark brown or black. In addition to the 

 much darker coloration, most WNA specimens have 

 a narrow pale streak along the dorsal midline ex- 

 tending forward from CFF an average of 46% (18- 

 80% of TL). This pale streak is not mentioned by any 

 author offering color descriptions of WNA material, 

 and it is not present in ENA material available to us 

 (180 from Skagerrak, Denmark; SIO59-50). This 

 streak appears to result from white connective tis- 

 sue binding skin to the dorsal midline in conjunc- 

 tion with an overlying unpigmented streak in the 

 skin. Removal of the overlying skin and examina- 

 tion with the aid of strong backlighting shows this 

 band to be present only in WNA material. Also, a 



difference in maximum lengths exists between ma- 

 ture specimens of M . limosa and. M. glutinosa. Of 

 250 specimens of the former, the longest is 510 mm 

 TL, and 133 exceed 400 mm, averaging 445 mm TL. 

 Tambs-Lyche (1969:283) reported "maximum 450 

 mm" for ENA material. Conel (1917:78) recorded a 

 maximum length of 79 cm from off South Harpswell, 

 Maine, and stated that of 20 specimens, only three 

 were between 31 and 36 cm; all others were from 50 

 to 79 cm. We have not seen any that large, and no 

 further description of the 20 specimens was given. 



Comments Apparently all previous authors have 

 assumed that M. glutinosa occurs across the North 

 Atlantic Ocean, but Saemundsson (1949) did not in- 

 clude it in his list of fishes from Iceland. However, 

 Konstantinov and Shchegelov ( 1958: 1745) stated "On 

 June 16, 1956, near the eastern coast of Iceland, at 

 the depth of 940 m, a M. glutinosa L., 28.5 cm long, 

 was caught in a Sigsbee trawl." We consider these 

 two species closely related, and have included 

 M.glutinosa in all the tables for comparison with M. 

 limosa. 



Discussion 



Owing to the absence of a fossil record, we are un- 

 able to state with certainty whether or not the new 

 world species treated herein are monophyletic or 

 polyphyletic. However, monophyly is assumed, based 

 on the synapomorphic character of having all bran- 

 chial ducts on either side combined into one single 

 external opening posterior to the gill pouches. Also, 

 monophyly of Myxine is supported by allozyme stud- 

 ies of hagfish from three continents. 1 



Relationships among these 14 species are in gen- 

 eral somewhat obscure on the basis of body propor- 

 tions and most counts. Although some means differ 

 (Tables 1-7), considerable overlap in ranges of counts 

 tends to mask significance. Only two species (both 

 new) differ notably in body proportions (Table 1); all 

 12 others are very similar. M. fernholmi has a shorter 

 prebranchial length and a correspondingly longer 

 trunk length and shorter tail. Myxine debueni also 

 has somewhat shorter prebranchial and tail lengths, 

 but the trunk length is similar to that of other spe- 

 cies, except for M. fernholmi. The few specimens 

 available (2 to 4) in 7 of the 14 species inhibits specu- 

 lation as to relationships, geographical separation 

 notwithstanding. Most counts are similar for most 



1 Fernhom, B. Swedish Museum of Natural History, Section for 

 Vertebrate Zoology, P.O. Box 50007, 5-110405, Stockholm, Swe- 

 den. Personal commun., May 1994. 



