Reproductive cycle and spawning patterns of Lizardfish, Saurida tumbil (Bloch, 1795) in southern water of Iran

Abstract

Reproductive activity of lizard fish, Saurida tumbil was assessed using histology. Sex ratio, maturation cycle, fecundity, gonadosomatic index based on 949 specimens collected monthly from north coast of Persian Gulf (Hormuzgan province), between June 2007 to June 2008. The sex ratio of the investigated fish was 1.92:1 (females: males). The results showed that the total length of female specimens ranged from 16.2 to 55.5 cm and total weight extended from 29.93 to 1587.12 g, while male specimen ranged from 18.1 to 44.00 cm and from 30.81 to 724.00g in total length and total weight respectively. The length-weight relationship valued for females and males were Wtot=0.0017L3.4214 R2=0.9578 and Wtot=0.0018L3.4015 R2=0.9699, respectively. Different stages of gonad development based on external appearance and histological observation of ovaries, revealed the existence of six stages for oocyte development of female specimens as immature, maturing, ripening, ripe, spawning and spent. The mean monthly values of GSI indicated that the species is a spring and autumn spawner with two peaks from September to November and a minor peak from February to April. Mean length at first maturity (Lm 50%) was 27.4 cm for females and 25.3 cm for males. Absolute fecundity of 30 maturity samples ranged between 48863-211689 as the number of eggs found in each ovary in the size range 40-50 cm.