Age and growth of Lactarius lactarius (Bloch & Schneider, 1801) from Karnataka, south-west coast of India

摘要

Age and growth of Lactarius lactarius was studied separately for males and females from the Karnataka coast using monthly length composition data collected from three major fish landing centres viz., Mangalore, Malpe and Karwar. The growth of L. lactarius was studied from length frequency data by ELEFAN I programme, and also by modal progression analysis using Gulland and Holt (1959) model after separating the modes using Bhattacharya (1967) method. The growth parameters estimated for males were: L-alpha = 240 mm, K = 1.01yr(-1) and t(0) = -0.0151; for females: L-alpha = 285 mm, K = 0.91 yr(-1) and t(0) = -0.0183 and for unsexed fishes (juveniles, males and females pooled) were: L-alpha = 294 mm, K = 0.84 yr(-1) and t(0) = -0.0215. The recruitment pattern showed two recruitment pulses every year, the major one during March and the minor one during June-August. The yon Bertalanffy growth formula fitted to L. lactarius indicated the fish to attain a length of 168 mm at the end of 1 year, 240 mm at the end of 2 years and 271 mm at the end of 3 years of its life. The estimated life span appears to be 3.57 years.