Maturation and spawning of the penaeid prawn Metapenaeus dobsoni (Miers) in brackishwater environment

Abstract

Periodic samples of the penaeid prawn Metapenaeus dobsoni collected over 20 months from January 1990 to August 1991, from perennial shrimp culture system Kannuvilakettu were analysed to study maturation and spawning of the shrimp in brackishwater environment. Salinity showed wide fluctuations as compared to other parameters viz., dissolved oxygen, pH, planktonic biomass etc. The monthwise distribution of males in different stages of maturity indicated that mature males occur almost throughout the year irrespective of salinity variations with peak occurrence in July and were predominantly high in size groups above 58 mm, indicating that maturation in males is size dependent rather than any other environmental factors.