Oiiiiilit l.tikr J'islics 515 



hatching were ahciut 5 mm loii)^. 1 lu- yimn^; attaih thcmM-lvo In llic hcail for 

 the first few tlays. 



Easily accessible accounts of the iiiterestinji l)ree<lin(^ habits of other allied 

 species of sticklebacks are given by (iill ('07, pp. 494-5or>), Jordan ('05, \'ol. 2, 

 pp. J2i)-2i\ ), and Sccley ("86. jtp. 77-7S). 



l/tthitiil. The normal habitat of the Hrook .'^tickU•back is the shallow water 

 of small streams or shallow ponds: it occurs more rarely in the swampy margins of 

 larger lakes. The con<litions of the breetling habitat are not kn(jwn in detail. 

 There may lie .seasonal and diurnal migrations as in the ca.se of some other species. 

 .Some a|)parently migrate to the deei> w.itcr iluring the day and return to shallow 

 water at night. 



Mverniann and Clark ( 'jo, \'ol. 1, p. 374) found that in Lake .\la.\inkuckee it 

 a|)pears to dwell in summer in rather deep water, but that at any time of the year 

 specimens could Ik? obtained by dre<lging in rather deep water, in which case they 

 would become entangled in the long water-weeds in which they apiK'ar to dwell, 

 .■specimens were olitaine<l by dredging uji rullisucria in water thirteen to si.xteen 

 feet deep. The l»est jjlace for them was among long XiltlUi. from a depth of 

 eighteen to twenty-three feet. In the winter they appeared to come near shore 

 ami stay among the weeds in shallow water. Barker ('18. p. 529) says that 

 shallow jMiols that have clear water all the year through, even though they may l»e 

 choked with vegetation and covered with floating plants during the summer, are 

 likely to shelter these interesting little tishes. fox ('_>_>. p. 4) records the occur- 

 rence of this stickleback in br,uki>li water <i| laml-locked pools, and in >aline 

 lakes of North Dakota. 



Food. The f<MKl of sticklebacks consists of insects, small crustaceans and 

 algae. Cill (07, j). 41/)) says that "The eggs and fry of other fishes sutler 

 severely from their attacks, but with apparently ecpial relish they take worms, 

 the minute entomostracans, the larvae and imagoes of insects, and small niollusks." 

 ForlK's ('Kvi, |). '>4 ) examined the stomach contents of five si)ecimens and found 

 them to contain algae and animal f«iod in alH)ut eijual amounts. The animal ftHnl 

 consisted maiidy of Crustacea { liiiloiiioslraai) anri midge larvae {Chiroiiomiis). 

 Ilankinson ('16, pp. 1^7, 141)1 found algae and inserts in the stomachs of these 

 fish from W'hitelish I'oint. .Michigan. The observations of Clark (C"f. Wilson. 

 '07, pi>. 4.'3-4J4 ) th.it a European stickleluick will eat Crustacea which are i)arasitic 

 on fish is of sjKcial interest, lie states: "If himgry or presseil for fiMMl the 

 sticklelwick will sometimes swallow the . /n/ii//. but generally s|K-nkiug they are 

 avoided, and if swallowed are ejected from the mouth." 



Wool man (*<)5. p. .U»> ( siys ih.it it eats the eggs of other s|Hries and susjiect* 

 that it has brought alM>ul a <lepletion of fish in certain waters. Mverniann an«l 

 Cl.irk ( ■-•o, p. 3751 consider the stickleback as carniv<»rous. snl>sisting nuiinly on 

 small animals of the lake. 'I'hey were found eating insect larvae. I'jitoniostraca 

 anil aniphi|Kids. Clemens ("24. |). 1.^51 re|H)rls on the foixl of thirteen Hr«M>k 

 Sticklekncks. l-.nlomoslracans and aipiatic inseiMs in variety form the princi{>nl 

 fiHMl. Init nnich other invertebrate material is present, and the e.\.-»ct ohamcter is 

 shown in tables published. < >ne siiecimen had eaten <;X fish eggs. JVarsc ("iS. p. 

 jfw) in examining the fiHwl of 1 10 of these stickleUicks from W isconsin lakes 



