76 Conservation Department 



P/ruroxus (iduncus. — In pond draining into C^attarangns creek; 

 eaten b}^ carp and carp sucker. 



Pleuroxus dcntkulatus. — In pond draining into Cattaraugus 

 creek. 



Pleuroxus striafiis. — In marginal zone only; eaten by carp 

 sucker. 



Sida cnjstaUina. — In all 3 lake zones, most abundant in lacus- 

 tric zone; eaten by cisco and j^ellow perch. 



Simocephalus serrulatus. — In marginal zone only ; eaten by bull- 

 head and carp. 



Simocephalus vetulus. — In marginal zone only; eaten by bull- 

 head and carp. 



Other Crustacea 



Mysis relicia. — Bottom form in lacustrie zone ; recorded in other 

 lakes as eaten by some of the larger fish. 



Pontoporeia hoyi. — Bottom form in lacustrie zone ; eaten by the 

 Cisco. 



6, — Contributions to the Early Life Histories of Lal^e Erie Fislies 

 By Marie Poland Fish 



Problem. — That nature has provided for most fishes to sj^awn 

 thousands or even millions of eggs annually without an apparent 

 increase and sometimes with an alarming decrease in the number 

 of individuals reaching maturity, evidences a most hazardous 

 career for the young, and points to the necessity for studying 

 early life histories. So unlike the Ivuown adults are they, and 

 so little clue to their identification do the larval forms give, that 

 the first and most difficult phase of the problem is their identi- 

 fication at various stages. When once these developmental series 

 have been worked out, further investigations are considerably 

 simplified. The young of only a few fresh water fishes had been 

 previously studied, so that practically all of those which came up 

 in our nets during the past summer were unlvuown stages, and the 

 determination of eacli one presented a new and often perplexing 

 puzzle. That the majority of specimens were less than half an 

 inch in length, lacking finrays and other diagnostic adult char- 

 acters, indicates the complexity of the problem. Upon the ability, 

 however, to recognize these species at all stages rests the success- 

 ful pursuit of studies on abundance and rate of growth, the map- 

 ping of distribution, the understanding of where in the life history 

 of each species great destruction occurs, and other questions which 

 we are striving to answer. 



Methods. — Petersen young fish trawls at all depths, Helgoland 

 trawls on the bottom, and meter nets at the surface and deeper 

 levels were used throughout the survey for the collection of young 

 fish matei'ial. The first step toward identifying the unknown 

 larvae thus captured was by making vertebral counts, this being 

 the only character which remains comparativel}' constant through- 

 out the lifetime of the individual. Shape, pigment marking, and 



