Premium
Centimeter vs. Inch‐Group Measurements for Describing Age and Size Composition of Fish Populations
Author(s) -
Cofer Larry M.,
Malvestuto Stephen P.
Publication year - 1983
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(1983)3<445:cvimfd>2.0.co;2
Subject(s) - dorosoma , micropterus , gizzard shad , bass (fish) , centimeter , fishery , lepomis , lepomis macrochirus , fish <actinopterygii> , age groups , biology , physics , demography , astronomy , sociology
Fish collected at West Point Reservoir, Alabama/Georgia, during 1981 were measured in centimeter and inch groups. The resultant length‐frequency distributions were compared for their value in management studies. Age distributions were assumed to be composed of overlapping normal curves and mixed distribution analysis techniques were used to isolate the curves. Centimeter measurements significantly improved the length‐frequency descriptions of populations of bluegill (Lepomis macrochirus), gizzard shad (Dorosoma cepedianum), and threadfin shad (Dorosoma petenense) and the interpretations of their age structures. Black crappie (Pomoxis nigromaculatus) ages were best described by centimeter measurements combined into 2‐cm groupings. Lengths at age for largemouth bass (Micropterus salmoides) based on scale reading were accurately produced from inch‐group analysis, but 3‐cm groupings provided similar results. We recommend that field measurements be made in centimeter groups; the groups can be combined later if desired.