We evaluated a large data set and confirmed that current standard weight (Ws) equations for white crappiesPomoxis annularisand black crappiesP. nigromaculatusare length-biased. We applied the regression-line-percentile (RLP) technique to length-weight data for 27,002 white crappies (175 populations) and 21,709 black crappies (80 populations) to develop new 75th-percentileWsrelationships. The proposedWsequations are log10Ws(g) = –5.642 + 3.332 log10TL(mm) for white crappies and log10Ws(g) = –5.618+ 3.345 log10TL(mm) for black crappies; TL is total length. There was no systematic bias evident inWrvalues (Wr= 100·W/Ws;Wis individual fish weight) calculated with the RLP-generated equations. Frequency distributions of population-meanWrvalues were consistent with those from studies of other fish species. No regional trends inWrwere observed. Moderate correlations were found betweenWrand population structure. Relative weight was generally highest in the spring, decreased after spawning, and increased throughout the summer and fall.
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