REPRODUCTIVE BIOLOGY OF THE GOBY PSEUDAPOCRYPTES LANCEOLATUS IN THE COASTAL MUD FLAT AREAS OF THE MEKONG DELTA

Abstract

This paper describes the reproductive biological characteristics of the goby, Pseudapocryptes lanceolatus, in the coastal mud flat areas of the Mekong Delta. The present finding is based on the examination of 1058 specimens which was monthly collected between January 2004 and June 2005. The sex ratio of female to male was 1.00:0.96. Observations on the seasonal distribution of maturity stages and variations in seasonal fluctuations in the gonadosomatic index (GSI), hepatosomatic index (HSI) and condition factor (CF) confirmed that the breeding season occurred with two spawning peaks in July and October. There was marked reduction in liver sized during the spawning season. Length at first maturity (Lᵐ) was 15.4cm and 16.3cm for females and males, respectively. The batch fecundity estimates ranged from 2,652 to 29,406 hydrated oocytes per ovary in the fish ranging from 12.8 to 22.4cm TL. The relationship between total length (TL) and batch fecundity (F) was F=0.1517*TL₃∙₉₇₅₇.