PROPOSED REVISION OF THE STANDARD WEIGHT (WS) EQUATION FOR REDEAR SUNFISH

Citation
Kl. Pope et al., PROPOSED REVISION OF THE STANDARD WEIGHT (WS) EQUATION FOR REDEAR SUNFISH, Journal of freshwater ecology, 10(2), 1995, pp. 129-134
Citations number
10
Categorie Soggetti
Limnology
ISSN journal
02705060
Volume
10
Issue
2
Year of publication
1995
Pages
129 - 134
Database
ISI
SICI code
0270-5060(1995)10:2<129:PROTSW>2.0.ZU;2-C
Abstract
Weight-length data were compiled from 289 redear sunfish Lepomis micro lophus populations. We applied the regression-line-percentile (RLP) te chnique to weight-length data for 150 redear sunfish populations to de velop a new 75th-percentile standard weight (($) under bar Ws) equatio n. The proposed RLP ($) under bar Ws equation, log(10)($) under bar Ws = -4.968 + 3.119log(10)TL where ($) under bar Ws is the standard weig ht in grams and TL is the total length in millimeters, is valid for fi sh greater than or equal to 70 mm TL. The English-unit equivalent, log (10)($) under bar Ws = -3.263 + 3.119log(10)TL where ($) under bar Ws is the standard weight in pounds and TL is the total length in inches, is valid for fish greater than or equal to 3 in TL. We used the remai ning 139 independent populations to evaluate the current [log(10)($) u nder bar Ws = -5.164 + 3.227(log(10)TL)] and RLP ($) under bar Ws equa tions for any length-related biases. We confirmed that the current ($) under bar Ws equation is length-biased. That is, relative weight (($) under bar Wr) values significantly decreased with increasing fish len gth for far more populations (N=45) than they increased (N=7). We test ed the proposed RLP ($) under bar Ws equation with the same 139 popula tions, and found no consistent length-related bias in Wr values calcul ated with the proposed RLP ($) under bar Ws equation (N=38, 29). Thus, We recommend the use of the proposed RLP ($) under bar Ws equation fo r redear sunfish.