520 
Fishery Bulletin 96(3), 1998 
Relationships among the sampled populations of M. glutinosa for cusp counts and slime pore counts. A solid 
line connecting two populations indicates no significant difference exists between the absolute values. A 
dashed line indicates no significant difference exists between the values expressed as percentages of the 
total slime pore counts. (A) Total cusp counts; (B) prebranchial slime pore counts; (C) trunk slime pore 
counts; (D) tail slime pore counts; (E) total slime pore counts. NWA = Northwest Atlantic; IGM = inner Gulf 
of Maine; OGM = outer Gulf of Maine; ENA = eastern North Atlantic; and MAC = mid-Atlantic coast. 
that has been widely attributed to M. glutinosa 
in the western North Atlantic thus appears to be 
valid only for the inner Gulf of Maine. 
In summary, the IGM group is significantly larger 
in total length than any other population sampled. 
Proportional measurements could be compared only 
between the IGM and ENA samples. In addition to 
having much greater total length, hagfish from the 
IGM sample are more slender (both in width and 
depth) and have shorter prebranchial segments and 
shorter, narrower tails than ENA specimens. Allo- 
metric effects are probably not responsible for these 
differences, which remain significant even when the 
IGM data set is restricted to animals of the same 
size range as that in the ENA sample (<400 mm). 
Total length, slime pore counts, and total cusp counts 
could be compared among all groups. The highest 
variability observed was in the total slime pore count. 
Specimens from the Gulf of Maine (IGM and OGM) 
differed from one another and from all other sample 
groups. In terms of the regional distribution of slime 
pores, there were significant differences between the 
IGM and ENA samples when compared as absolute 
values or as percentages of the total slime pore count. 
Differences in the regional distribution of slime pores 
