STONEROLLER 



Food. — Because good keys for 

 the separation of minnow species 

 were not available until recent 

 years, much of the literature and 

 the records of stomach contents for 

 the bluntnose minnow has probably 

 been confused with those of the fat- 

 head minnow. More recent studies 

 indicate that the feeding habits of 

 these two species are similar; so the 

 records, general as they are, could 

 apply to either species. 



The bluntnose minnow is known 

 to eat diatoms, algae, aquatic in- 

 sects, entomostraca.ns, fish eggs, fish 

 fry, and oligochaete worms. Oc- 

 casionally this minnow will eat its 

 young. Some stomachs of the 

 blunt-nosed minnow contain only 

 phytoplankton ; others, only sur- 

 face drift ; and others large percent- 

 ages of insects, higher plants, zoo- 

 plankton, debris, or silt. A sum- 

 mary of food studies by several 



workers shows that, in general, the 

 food percentages are as follows : In- 

 sects, 15.9; crustaceans, 3.5; ento- 

 mostracans, 2; surface drift, 10.7; 

 annelids, 0.5 ; zooplankton, 6.9 ; 

 phytoplankton, 35; plants, 8.7; 

 algae and diatoms, 4,9; and silt and 

 debris, 11.8. 



Importance. — T h i s minnow is 

 easily propagated and has been 

 widely introduced. It has been 

 propagated in Michigan at the rate 

 of 104,800 fish (250 pounds) an 

 acre. In general, this species seems 

 less prolific than the fathead min- 

 now, but in Ohio, 473,350 to an acre 

 of water have been raised. This 

 species will not withstand crowding 

 in minnow containers so well as the 

 fathead minnow. It is important 

 as a food for game fish, because of 

 its preference for large lakes where 

 jrame fish are abundant. 



STONEROLLER Camposfoma anoma\Mm 



Also called Racehorse Chub. 





LIFE HISTORY 



DeHcription.. — I'lump, sturdy 



black crescent on dorsal fin of 

 adults; large tubercles on top of 

 mrnnowTundersiung suckerlike li^ad of breeding males; lining of 

 mouth with horny ridge forming abdominal cavity black, intestine 

 the lower lip; scales large, some- very long and wound spirally 

 times flecked with black pigment; around air bladder. 



115 



