The reproductive performance of the broodstock was measured at each stage of the maturation and spawning progression. Measures of maturation rate, spawning rate, fertility rate, hatch rate and nauplii production rate were gained. The reproductive performance was found in the imported Specific Pathogen Free (SPF) broodstock from Shrimp Development System (SDS), Florida and USA.
The no of spawning, egg 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. We mixed the mentha piperita (immunomodulant) with natural feed. Female size is improved 30 g to 52 g the mean number of eggs per spawning better from 160,000 to 542,000. Although female body weight was gradually larger through the study period and the larger females would be expected to harvest more eggs per spawning and hatching. The hatching rate was enhanced from 3rd spawning onwards.
The Nauplii Production Rate (NPR), which is to resolve of egg production and hatching rate, showed a considerable increase from 49% to 96%. In 10th spawning, all the activities were increased. This information can be used to select broodstock for hatchery production.