516 
A population profile for hagfish, 
Myxine glutinosa, in the Gulf of Maine. 
Part 2: Morphological variation 
in populations of Myxine 
in the North Atlantic Ocean 
Frederic H. Martini 
Michael R Lesser 
John B. Heiser 
Shoals Marine Laboratory, G-14 Stimson Hall 
Cornell University, Ithaca, New York 1 4853 
Current address (for F H. Martini): 507 1 Hana Hwy. 
Haiku, Hawaii 96708 
E-mail address (for F H Martini) martini@maui.net 
Abstract .—The species Myxine 
glutinosa has long been recognized as 
encompassing both eastern and west- 
ern North Atlantic populations. Wisner 
and McMillan (1995) have proposed 
splitting the species into M. limosa 
(Girard, 1858; western North Atlantic) 
and M. glutinosa (Linnaeus, 1758; east- 
ern North Atlantic). We examined a 
variety of morphological characteris- 
tics, including cusp counts, slime pore 
counts (total, prebranchial, trunk, and 
tail), total length, and body proportions 
(prebranchial, trunk, and tail length, 
maximum width and depth, and depth 
at cloaca). Several western Atlantic 
populations of varying size were com- 
pared with one large sample from the 
waters between Sweden and Denmark. 
The results indicate that although 
specimens from the Gulf of Maine dif- 
fer significantly from those collected in 
the eastern North Atlantic, specimens 
collected from the mid-Atlantic coastal 
region of the United States and from 
northern Canadian waters are less dis- 
tinctive. In addition, there are signifi- 
cant morphological differences among 
the populations sampled in the west- 
ern North Atlantic. It is therefore sug- 
gested that until and unless molecular 
data indicate otherwise, the species 
name M. glutinosa be retained as en- 
compassing both eastern and western 
North Atlantic populations. 
Manuscript accepted 13 January 1998. 
Fishery Bulletin 96:516-524 (1998). 
Only one hagfish, Myxine glutinosa 
(Linnaeus, 1758), has been found on 
both sides of the North Atlantic 
Ocean; this is the only hagfish re- 
ported from within the Gulf of 
Maine. Myxine glutinosa are an 
important species in the Gulf of 
Maine because 1) they are present 
in substantial numbers (densities 
may reach 500,000/km 2 ), and they 
may have a considerable impact on 
the benthic community (Lesser et 
al., 1996; Martini et al., 1997b), 2) 
they have direct and indirect effects 
on commercial fisheries in the Gulf 
of Maine, through predation on 
groundfish in fixed gear fisheries 
and through competition for shrimp, 
and 3) they have commercial value 
as the basis for a leather fishery 
that provided Gulf of Maine fisher- 
men with $1.2 million in 1996. 
The first part of this study (Mar- 
tini et ah, 1997a) presents morpho- 
logical data and a population pro- 
file for hagfish in the inner Gulf of 
Maine. In this report we compare 
the morphological characteristics of 
this population with those of M. 
glutinosa populations in other geo- 
graphical regions. Wisner and 
McMillan ( 1995) proposed splitting 
M. glutinosa into M. glutinosa 
(Linnaeus, 1758) for the eastern 
North Atlantic (ENA) and Myxine 
limosa (Girard, 1858) for the west- 
ern North Atlantic ( WNA). The pro- 
posed separation was based on dif- 
ferences in size at sexual maturity, 
maximum size, and the color of pre- 
served specimens. We undertook 
this analysis initially to see if there 
were significant morphometric dif- 
ferences that would support the 
separation of species. This ulti- 
mately led us to perform statistical 
comparisons among our morpho- 
logical data, collected in the inner 
portion of the Gulf of Maine, and the 
data of other researchers working 
with eastern and western North At- 
lantic populations of M. glutinosa. 
Materials and methods 
Wisner and McMillan included mor- 
phometric data for Myxine collected 
over a very broad area. The latitu- 
dinal limits were 33°46'N to 66°39'N, 
and the longitudes ranged from 
79°42'W to 52°13'W. Of the 138 
specimens cited in their report, only 
28 (20%) were collected within the 
boundaries of the Gulf of Maine. 
Their study provided detailed data 
