Research Article
Kannan D*, Thirunavukkarasu
Abstract
The reproductive performance of the broodstock was assessed at each stage of the maturation and spawning process. Measures of maturation rate, spawning rate, fecundity, hatch rate and nauplii production rate were obtained. The reproductive performance was found for the imported Specific Pathogen Free (SPF) broodstock from Shrimp Improvement system (SIS), Florida, USA. The no.of spawning, eggs quantity, fertility, hatching rate and nauplii production were lowest in 1st to 3rd spawning when females were 7 months old and increased from 4th spawning rate onwards. As the size of females increased from 30 g to 52 g the mean number of eggs per spawning increased from 150,000 to 442,000. Although female body weight was increasingly larger through the study period and the larger females would be expected to produce more eggs per spawning and hatching. The hatching rate was increased from 3rd spawning onwards. The nauplii production rate (NPR), which is a function of egg production and hatching rate, showed a significant increasing from 48% to 96%. In 10th spawning all the activities were increased. This information can be used to select broodstock for hatchery production.