A temperature compensated von bertalanffy growth model for tagged red drum and black drum in Texas bays

Abstract

Estimates of von Bertalanffy growth model (VBGM) parameters K and L ∞ were made for red drum ( Sciaenops ocellatus), and black drum ( Pogonias cromis), tagged and recaptured in Texas bays from November 1975 through June 1985. An annual temperature model was used to examine the growth model when periods of cold temperature were excluded. The best fit of the VBGM for red drum was based on time at large expressed in day-degrees with the coldest 60 days of the year excluded and yielded VBGM parameters estimates (± SE) of K = 0.422 (0.023) and L ∞ = 918 (21) mm. Black drum data were best fitted with time at large expressed in days with the coldest 120 days of the year excluded and yielded VBGM parameters of K = 0.219 (0.027) and L ∞ = 798 (42) mm. The exclusion of cold periods added to the body of evidence suggesting that scales and otoliths may be useful for ageing these species in the Gulf of Mexico. The source of the tag return (recreational fishermen, commercial fishermen, Texas Parks and Wildlife personnel) affected the parameter estimates. The pooled data, however, appeared to give the most reliable estimates.