55] STUDY OF SOUTHERN WISCONSIN FISHES— CAEN 55 



83. Etheo stoma jessiae (Jordan & Bray ton). 



Not an uncommon species in lakes of certain kinds. I took the species 

 first in Oconomowoc lake, but it is much rarer in the large, gravel bottom 

 lakes than in the smaller, soft bottomed lakes and ponds. I have the species 

 from Laura lake, the larger of the Skidmore ponds, Okauchee ponds, 

 Forest lake, and the Genesee lakes. It is a small, inconspicuous darter, 

 rapid in movements, and using the darter trick of stirring up the bottom 

 by a violent flick of the tail in order to hide or escape enemies. It is dis- 

 tinctly a solitary fish, being much less gregarious than any of the preceding 

 species, and seldom more than a single specimen in taken in the net at one 

 sweep. The fish breed in May, but I have taken gravid females in Ocono- 

 mowoc lake as late as June 12. They spawn in the shallow water along 

 the shore, usually in a clump of submerged vegetation. The food is typical 

 of the darters, being largely entomostraca and insect larvae, mostly 

 Chironomus, but with some nymphs or small Crustacea (Hyalella) as well. 

 The species is often rather heavily infected with the cysts of the parasite 

 (?) Diplostomulum cuticola. 



84. Etheostoma coeruleum Storer. Rainbow Darter. 



While this species somewhat resembles the preceding, it is a fish of 

 the larger gravel lakes, Oconomowoc, Pine, La Belle, Okauchee, North, 

 Keesus, Pewaukee, Silver, Golden and Beaver. It is in all respects a very 

 typical darter, and one of the most common species of the group. It 

 inhabits the shore water along with Boleosoma nigrum and Notropis 

 blennius, and few collections along the lake shores fail to yield two or three 

 of this species. It is very fast in its actions, and resembles Diplesion 

 blennioides in its habit of seeking refuge under stones or sticks though 

 it does not remain under objects for any length of time. The fish spawn in 

 May, usually the latter half, laying in shallow depressions well up toward 

 the shore, within the zone of wave action. The food is mostly cladocera 

 and copepods, while Crustacea (Hyalella and Gammarus) form about 25% 

 of the total bulk. Often used as bait for silverbass and perch, though not 

 desirable because of the dark color and not very great vitality. 



85. Etheostoma flabellare lineolatum (Agassiz) . Fan-tailed darter. 



In delicacy of markings, if not in color, this is one of the most attractive 

 of our darters. It is an inhabitant of very rapid water, being associated 

 most frequently with Coitus bairdii bairdii and Noturus flavus. It is very 

 local in its distribution, being confined to those parts of the various rivers 

 in which the current is great and the bottom hard. The Little Oconomowoc, 

 Oconomowoc, Scuppernong and Bark rivers contain large numbers of 

 fan-tails where these conditions prevail, and it is a rare fish in the Muk- 

 wonago river. They attain a length of 3 inches in the Scuppernong, though 

 the average size is 2\ inches. The fan-tail is very rapid in its movements, 

 probably the fastest of all the darters, an-i this speed stands it in good 



