Growth parameter estimates for Omani abalone ( Haliotis mariae, Wood 1828) using length-frequency data

Abstract

Length-frequency data for Omani abalone ( Haliotis mariae) from two areas (Sadh and Hadbin) of the Dhofar coast of the Sultanate of Oman were used to fit von Bertalanffy growth curves by ELEFAN, MULTIFAN and Non-Linear Least Square Fitting methods. The first two methods were directly applied to length-frequencies whereas the last method was used on the length modes determined by the MIX method. The growth parameter values by sex and area were not significantly different. The parameter estimates combining sexes and areas were: ELEFAN- L ∞ = 126.6 mm shell length (SL) and K = 0.97 yr −1; MULTIFAN- L ∞ = 140.0 (±0.42) mm SL and K = 0.67(±0.003) yr −1; and Non-Linear Least Square Fitting- L ∞ = 152.8 (±13.24) mm SL, K = 0.58 (±0.14) yr −1, and t 0 = 0.55 (±0.14)yr. The estimates by the Non-Linear Least Square Fitting method were superior to others for the data sets used in this paper. There were two recruitment pulses. The growth patterns as determined by the growth performance index (ϑ′) were higher for Omani abalone than those for other abalone species of similar sizes. Growth performance indices combining sexes and areas were similar for the MULTIFAN and Non-Linear Least Square fittings while that for ELEFAN was slightly higher.