Family COTTIDAE 



THE SCULPIN FAMILY 



This family contains many genera and species, many of which are 

 known as sculpins, muddlers, and miller's-thumbs. Many species live in 

 the sea, though a number have taken up their abode in fresh waters, ap- 

 parently to escape competition, and are found throughout North 

 America, Asia, and Europe. Three or four species are found in Minnesota. 



The sculpins are grotesque fishes. The body is elongate, the head very 

 large and much depressed. The eyes are placed high in the head, and the 

 space between them is narrow. The edge of the preopercle has one or 

 more spinous processes. Teeth are present on the jaws and usuallj^ also 

 on the vomer and palatines; the upper jaw is protractile, and the maxil- 

 lary is without a supplemental bone. Gill-rakers are either short and 

 tuberclelikc or absent. The body is naked or partially covered with 

 scales, prickles, or bony plates, but never entirely scaled. The lateral line 

 is present. The pectoral fins are very large, and the ventral fins are 

 thoracic. Pseudobranchiae are present. There are usually 4 to 8 pyloric 

 caeca. 



Key to Common Species of Family COTTIDAE 



1. Gill-membranes free from isthmus; dorsal fins widely separated; head long; 



body slender; eyes very large; small but definite slit behind last gill 



Deepwater Sculpin. Triglopsis thorn psoiiii Girard 



Gill-membranes not entirely free from isthmus; dorsal fins scarcely separated; 

 head broad: body fusiform; eyes smaller; no slit behind last gill 2 



2. Lateral line complete Spoonhead Muddler, Coitus ricei Nelson 



Lateral line incomplete, extending back to region of second dorsal fin 3 



3. Pelvic rays typically I, 3;* palatine teeth few or absent 



Slimy Muddler, C otitis cognatus Richardson 



Pelvic rays typically I, 4; palatine teeth well developed 



Northern Muddler, Cottus bairdii bairdii Girard 



*A sheath encloses the spine with the first soft-ray and the spine is not visible without 

 dissection. 



GENUS Triglopsis Girard 



The fishes of this genus are restricted mostly to the deep waters of the 

 Great Lakes. 



DEEPWATER SCULPIN 



Triglopsis thompsonii Girard 



This sculpin differs from those of the following genus, Cottus, in hav- 

 ing a very slender body and a long, narrow head. The gill-membranes 

 are free from the isthmus. The eye is very large. The skull is cavernous. 



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