Seasonal Variation in Growth and Survival of Penaeus monodon Larvae Under Hatchery Conditions

Abstract

The present paper deals with various aquatic abiotic parameters which influence the spawning, hatching and larval metamorphosis of Penaeus monodon in controlled conditions. Water temperature, salinity and dissolved oxygen as well as general hygienic conditions were found to be the critical factors for the successful gonadal hydration, breeding and survival of young ones of Penaeus spp. Optimum ranges of hydrographic parameters were temperature 28-30oC, salinity 28-33 ppt and dissolved oxygen close to saturation. The larvae were fed on diatoms (Chaetocews sp.), Artemia cysts and egg custard. The algal culture was maintained in the hatchery itself under conducive conditions. The hygienic conditions of the hatchery were maintained by using chemicals such as chlorine, EDTA and formalin. Antibiotics like oxytetracycline and chloramphenicol were used as prophylactic measures in order to prevent outbreak of diseases and infections. The present experiments conducted in Maharashtra revealed that best results in spawning, larval survival and growth could be obtained during September-October months, when temperature and salinity were in favourable ranges.