LAMPREYS AND FISHES 



Fig, 2-]}^. — Common sucker, Catostomus cotnmersonii. 



sucking mouths (Fig. 273) located well under the head, not at 

 the end of it as in most fishes, and by their thick fleshy lips. 

 Fullgrown suckers may be a foot long, but in small streams 

 they tend to be much shorter. 



In early spring soon after the ice breaks, suckers usually 

 swim upstream into the shallows to lay their eggs, but this 

 does not appear to be a universal habit, for some spawn in 

 ponds. By late July the younger fish are nearly an inch long, 

 and at this stage they have terminal mouths instead of suck- 

 ing ones like their parents. Although suckers are usually 

 a nondescript olive, during the breeding season the fins of the 

 male become tinged with rose color. One female spawns with 

 two males, one of them crowding against each side of her, 

 discharging their milky sperm fluid (milt) as soon as any eggs 

 leave her body. 



Suckers are bottom feeders on mud rich in diatoms, midges, 

 worms, and mollusks. They are used, to some extent, for 

 food, and those of Lake Erie are of considerable commercial 

 importance. 



Size. — Up to 18 inches, or more, but this is unusually large 

 especially for small streams. 



Distrihutinn. — Abundant in almost every small stream and 

 pond east of the Rocky Mountains. 



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