Oiiciila Lake l-hUcs 4' '3 



l"i>h treek, a trilnitary uf Oneida I-ake (Xo. 515). In our collections wc found 

 two diseased s|)eciniens ( Xos. 403, 413). One had small ohlonjj whitish objects in 

 its alKlomen. which could Ik- seen throuKh tlie ventral body wall. 



luonomk RrUitioiis. If this darter is as destructive to the eKf,'s of other 

 fishes as it ai)pears to he, it niav because of its lar^e nunil)ers and general distri- 

 bution be a seri(jus factor in reducing the numbers of sunfish. black liass and other 

 useful sfjccies that jjlace their e|,'(,'s on the bottom in ( )neida I^ike. Their small 

 size, skulking ways and protective markings would make them caiable of easily 

 evading fish guarding the eggs. 



Rcfi-rfjicfs. .\bbott. '73, '84: Haker, 'i(>: Hean, 'i)j: I-juIxkIv. 'io; I-:ver- 

 manii and Kendall. ■</>: Fowler, '06; Jordan and Kvermann, "</); .\sh, 'oS; Seal, 

 ■.)-•: Wright, '18; Wright and .Mien, '13. 



Poecilichthys exilis (Cirard). Iowa D.VRTtiR. The Iowa Darter was taken 

 in ;i few places in ( )neida Lake and in streams connected with it. It is a small 

 species, seldom (jver two inches in length. Its most distinctive characteristic is its 

 short dorsal fins, the anterior having from seven to ten spines, and the posterior 

 nine to eleven soft rays. In form it is much like the Tessellated Darter, but it 

 lacks the W-.shaped markings on the sides possessed by this minnow, and is ordi- 

 narily darker in color. The young of the two species are often hard to distinguish, 

 but in the Iowa Darter the dark bars confine<l to the sides of the l)o<ly, wiih the 

 alternating brownish blotches, are usually evident and diagnostic. 



Hn-fding Habits oitd Life History. Hree<ling males of this sja-cies are among 

 the most beautiful of our darters. They have the color |)attern accentuated, and 

 latent bright reddish brown sjxits and similar colors on the sides of the belly, and 

 one on the distal half of the spiny dorsiil fin. .\ g(M><l figure <if tme of these 

 darters is given by lMirl>es and Richardson Coi), opp. p. 30^)). lU-nsley ( "15. ]>. 48) 

 descriU's these breeding males more in detail as follows: "The aiUerior dorsal 

 fin lias the lasal two-thirds deej) blue green, darker between the ray>. There is a 

 narrow b.nid of bine at the margin of the fin. se]>arated from the Kisal kind by a 

 stripe of orange. Sides with angular cinnamon blotches to and along the l>ase of 

 llii- anal. Hasal membranes of the jKisterior dorsal, caudal and anal with diffuse 

 greenish." 



Hensley (I.e.") finds the breeding season in (Ontario to Ik.- the latter i>art of 

 May and Jime. He says the eggs are deposited on stones, esix-cially in shelteretl 

 crevices, often in water only a few inches dee]); and the fish arc ci»irmoi>ly in 

 KHMips, in which there is a lively com|>etition among the males for the jxissession 

 of the females. Jaffa ('17, |). ~j) found m.iles in full breeding dress with milt 

 flowing freely when totiche«I, and also t\]<c females, in streams three to four fi-rt 

 deep near Houlder. Colorado, from April jjwA to June i<.t. In the lalx>ratory he 

 found the incubation jHriiMl of the eggs to \tc from eighteen to twenty-six «!ays. 

 and the voting at hatching to lie 3.4 mm long. I'".vermann and Clark Cjo, Vol, i. 

 ]v 443) fouiul females, .\pril J7, njoi, at I-ike Maxinkuckee, which were full of 

 spawn. 



I'.x.nmples of this sin-cies taken by »is in Oneida Ijike were sm.ill, uiuler two 

 inches in length, except one sj>ccinien which was taken at Diniham Island (No. 

 53<)^ : this was al>«)ut two and one-half inches long. 



