39] STUDY OF SOUTHERN WISCONSIN FISHES— CAHN 39 



heavy vegetation except for momentary protection. I have taken the 

 species in Lac La Belle, where it is established and breeding. In rivers 

 it is usually associated with Notropis comutus, Ilybopsis kentuckiensis and 

 Campostoma anomalum. A beautiful minnow, but not hardy enough for 

 bait purposes. 



39. Notropis comutus (Mitchill). Common Shiner. 



The characteristic minnow of Ashippun, Bark, Mukwonago and Fox 

 rivers where it is exceedingly abundant. In the Bark and Ashippun rivers 

 I have often taken a glass minnow trap so full of these shiners (as many 

 as 277 in a single trap) that movement within the trap was impossible. 

 The fish attain a large size, often reaching 6 and 7 inches, and are excellent, 

 though short lived and tender mouthed bait. They are commonly used for 

 clear water trolling, not for casting. They prefer clear water (in fact they 

 cannot survive in muddy water) , gravel bottom with protecting weeds near 

 at hand, and some current. As a result of excess bait being thrown over- 

 board, the species is sometimes found established in lakes — Oconomowoc, 

 Pine, North (very abundant), and Okauchee. The food is about equally 

 divided between entomostraca, Crustacea and insect larvae as animal 

 food, and algae, slime, and particles of aquatic plants on the vegetable side. 



40. Notropis atherinoides Raf. Shiner. 



Taken by me only in the Menomonee river, where it is not very com- 

 mon. Here it was associated with Pimephales promelas. The food consists 

 almost wholly of animal matter, largely insect larvae, but many adult 

 insects which have fallen on the surface are eagerly snapped up. I have 

 found these fish likewise infected with a species of Ligula. 



41. Notropis rubrifrons (Cope). Rosy-faced Minnow; Skip-jack. 



The only place I have taken the species is in the Mukwonago river, 

 where it occurs in large numbers at certain seasons of the year. It would 

 appear that the species comes up from the Fox river in late spring, return- 

 ing to that river again about October. In no other way can I explain the 

 complete disappearance of this species which is so common in the Muk- 

 wonago during the summer. Inhabiting water two feet or more in depth, 

 the species is often eaten by bass (Micropterus salmoides) and pickerel 

 (Esox lucius). A very interesting minnow, about which little is known. 



42. Rhinichthys atronasus (Mitchill). Black-nosed Dace. 



This peculiar little minnow which, because of the profusion of small 

 black pigment spots looks as if it were heavily infected with cysts of 

 Diplostomulum cuticola, has been taken only from the Lake Michigan 

 drainage in the Menomonee river. Here it is quite common, associated with 

 Pimephales promelas and Clinostomus elongatus. It prefers rapid, clear 

 water, and gravel bottom with some vegetation. The mouth is rather 

 sucker-like and the food consists largely of vegetable matter, together with 

 what entomostraca and small Crustacea and insect larvae may come 

 with it. 



