SIXTY-TWO SPECIES OF FISHES FROM LAKE ERIE 
385 
Family COTTIDj^E, Sculpins 
54. Triglopsis thompsoni Girard. Deep-water sculpin; cockatush. 
RECORD OP CAPTURE 
Young specimens of this interesting cottid were taken in 1928 from the end of 
July until the middle of August in the deeper regions, the first time the species has 
ever been recorded in Lake Erie although adults had been found previously in all ‘of 
the other Great Lakes (M. P. Fish, 1929 (1)). During 1929 none was taken. The 
species is interesting in that it is a relic of a former marine arctic fauna, a close relative 
of the present circumpolar genus Oncocottus, and degraded through fresh-water life 
from a species stranded here in glacial times. 
DESCRIPTION 
Tbe slender body, elongate cavernous head, gill-membranes free from the 
isthmus, widely separated dorsal fins, and series of bony processes along either side 
of dorsal aspect and along ventral ridge behind the anus, and in larger specimens on 
dorso-lateral aspect halfway to lateral line from above vent to a point more than 
halfway to caudal, distinguish these specimens from all other sculpins taken. 
12.5-millimeter stage . — Total length, 12.5; standard length, 10.25; length to vent, 
5.0; length of head, 3.25; length of pectoral, 3.0; greatest depth, 1.8; diameter of eye, 
0.6 millimeter. Myomeres, 10 to vent plus 23 behind. Dorsal VIII, 19; anal 15; 
pectorals 15; ventrals I, 4 on one side (in other specimens both sides I, 3), inserted 
directly below pectorals; caudal exceedingly long. Body very elongate and slender; 
elongate head, rather cavernous, with elliptical eyes smaller and interorbital space 
wider than in adult specimens (adult eye 4 in head, much wider than interorbital 
space and nearly as long as snout, while in these young it is 5.4 in head, slightly less 
than interorbital space and nearly as long as snout); low dorsal profile gently rising 
from terminal mouth to back of head, depressed between eyes; snout long and pointed 
in profile, rather spatulate from above. Rather long, slender, little curved preoper- 
cular spine, directed backward and upward, with 3 smaller spines below, the second 
directed backward, and the others downward; otherwise head unarmed. Body 
armature consisting of a double series of long, very sharp bony spines directed back- 
ward on either side of dorsal aspect from behind head to end of myomeres, and a 
similar ventral series from behind vent to end of anal fin (about 34 dorsal and 18 
ventral). Gill membranes almost free from isthmus, forming only a broad fold across 
it; branchiostegals 6; dorsals rather widely separated; lateral line conspicuous. 
Pigmentation. — A few small round chromatophores occur on top of head, smaller 
stellate ones between the eyes, and a few on sides of head and around base of pectorals. 
