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Reproduction and Recruitment of Gizzard Shad in Kansas Reservoirs
Author(s) -
Willis David W.
Publication year - 1987
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8659(1987)7<71:rarogs>2.0.co;2
Subject(s) - dorosoma , gizzard shad , spawn (biology) , gonadosomatic index , fishery , reproduction , biology , trawling , gizzard , population , zoology , ecology , fishing , fish <actinopterygii> , fecundity , demography , sociology
Gizzard shad (Dorosoma cepedianum) were collected from 19 Kansas reservoirs to evaluate reproduction and recruitment. Reproduction occurs yearly in large reservoirs (500‐6,000 hectares) in Kansas, regardless of adult population structure, but survival to adulthood is sporadic. Gizzard shad ovaries were collected near the peak of the 1983 spawn from Melvern Reservoir, one of the 19 impoundments. Egg‐diameter measurements from these ovaries had discrete modes, indicative of multiple‐spawning capabilities. However, the gonadosomatic index (GSI) and trawling data were unimodally distributed in both 1983 and 1984, which indicated that a single spawning period extended from early May to mid‐June. Statewide, proportional stock density (PSD) and mean relative weight (Wr) of adult gizzard shad the previous fall had significant influences on the quantity of young‐of‐the‐year shad produced. Egg‐diameter data from Melvern Reservoir gizzard shad indicated that the larger females contained mostly eggs of one size, while smaller females contained eggs of two sizes. Thus, populations dominated by small adults (180‐279 mm) produced a broader size range of young‐of‐the‐year fish.