PIAVIS. GEORGE W. 



1962. Exposure of several developmental 

 stages of the sea lamprey, Petromyzon 

 marinus , to selective larvicides. Copeia 

 1962(3):652-653. 



Larvae of several developmental 

 stages were exposed to a series of 

 compounds selectively toxic to sea 

 lampreys. Exposure of earlier stages 

 (blastula through hatching) slowed de- 

 velopnnent and led to death. Prolarvae 

 of Stage 17 survive to Stage 18 but 

 then die if still exposed. To assure 

 complete destruction of young of the 

 year, streams shovild be treated no 

 sooner than 40 days after the last 

 spawning. 



POWERS, CHARLES F., DAVID L. JONES, 

 and JOHN C. AYERS. 

 1959. Sources of hydrographic and mete- 

 orological data on the Great Lakes. 

 U.S. Fish Wildl. Serv., Spec. Sci. Rep. 

 Fish. 314, iii+ 183 p. 



Lists 657 inland and 472 onshore 

 sources of meteorological and hydro- 

 graphic data. All inland (mostly weather 

 stations) and 429 onshore (weather 

 stations, water-treatment plants, 

 powerplants, industrial plants. Coast 

 Guard stations) were classed as 

 "usable." Information is recorded on 

 kinds of data and periods of years 

 covered. Work done by Great Lakes 

 Research Division, The University of 

 Michigan, under contract with Bureau 

 of Commercial Fisheries. 



PRICE, JOHN W. 



1963. A study of the food habits of some 

 Lake Erie fish. Ohio Biol. Surv., Bull., 

 N.S. 2(l):l-89. 



Stomach contents were examined from 

 14,118 fish of the following species: 

 smelt; trout-perch; yellow perch; spot- 

 tail shiner; sheepshead (freshwater 

 drum); white bass; channel catfish; 

 walleye; alewife; and gizzard shad. 

 According to availability of materials, 

 infornnation is given along the lines: 

 diurnal variation; seasonal variation; 

 variation by area; and variation with 

 size of fish. Among the significant 

 general observations were: broad re- 

 placement of the formerly innportant 

 mayflies by tendipedid larvae; selec- 

 tion for cladocerans over copepods; 

 importance of amphipods to trout-perch, 

 yellow perch, and sheepshead; basically 

 piscivorous diet for walleyes only; and 



significant consumption of algae by 

 gizzard shad only. Research was under 

 contract with the Bureau of Comnner- 

 cial Fisheries. 



PYCHA, RICHARD L. 



1961. Recent changes in the walleye fishery 

 of northern Green Bay and history of 

 the 1943 year class. Trans. Anner. 

 Fish. Soc. 90(4):475-488. 



The 1929-57 statistics on production, 

 fishing intensity, and availability of 

 walleyes are described, and the more 

 recent fluctuations are examined in 

 relation to evidence on year-class 

 strength as indicated by scales of fish 

 collected in 1949-58. The strength of 

 the 1943 year class was phenomenal. 

 The unprecedented abundance and the 

 record fishing intensity it stimulated 

 carried production to the alltime high 

 of 1,294,000 pounds in 1950. Before it 

 passed from the commercial fishery, 

 the year class contributed an estinnated 

 1,173,000 fish weighing 3,355,000 

 pounds. Sonne year classes (1945, 1946, 

 1948) were extremely small. The abun- 

 dance of certain later year classes 

 (1950, 1951, 1952) approached or ex- 

 ceeded that of the 1943 year class at 

 the younger ages, but greatly increased 

 mortality, attributed to sharp expan- 

 sion of the sport fishery, linnited their 

 total production. 



PYCHA, RICHARD L. 



1962. The relative efficiency of nylon and 

 cotton gill nets for taking lake trout 

 in Lake Superior. J. Fish. Res. Bd. 

 Can. 19(6):1085-1094. 



Nylon nets took 2.25 tinnes as many 

 legal-size (1-1/4 pounds, dressed, or 

 heavier) and 2.8 tinnes as nnany under- 

 sized lake trout as cotton gill nets. 

 These ratios agree well with those de- 

 termined by earlier investigators. Mean 

 sizes of fish in the two kinds of nets 

 did not differ greatly, and the "effi- 

 ciency ratio" had no seasonal trend. 



PYCHA, RICHARD L., and LLOYD L. SMITH, 



JR. 



1955. Early life history of the yellow perch, 



Perca flavescens (Mitchill), in the Red 



Lakes, Minnesota. Trans. Amer. Fish. 



Soc. 84:249-260. 



Study of the life history during the 

 first year of life with particular refer- 

 ence to: scale fornnation; body-scale 

 relation; timing and variability of 

 growth; length- weight relation; and food 

 habits in relation to growth and sur- 

 vival. 



31 



