In recent years, techniques for nursing shrimp post larvae is receiving increased attention of aquaculturists worldwide as a potential means to improve aquaculture production through application as a transitional nursery system sandwiched between the hatchery and grow-out ponds. Even though only sketchy information is available in this line, the use of nursery for shrimp culture is on the surge as the potential benefits in subsequent grow-out ponds include the following: rapid and compensatory growth, greater control to diet and water quality, easy to manage high stocking densities, reduced unit cost production, more number of annual crops by shortening the grow out cycle, strong immune system and eventually maximum survival at the end of nursery period. More recently, nurseries have been advocated for biosecurity reason as well. Keeping these facts in mind, an attempt was made to evaluate the growth and survival of shrimp post larvae besides management practices in nursery attached to a Shrimp farm.
To achieve this, post larvae (PL 8-PL10) of Litopenaeus vannamei were procured from the commercial shrimp hatchery and stocked in the shrimp farm indoor nursery tanks (6 nos. N1 - N6) with 18 ton capacity, 6" height) and the PL were kept in nursery for 30 days. The necessary physico- chemical parameters were monitored twice a day in each tank and maintained within the permissible range (pH 7.6-8.3; Salinity 28 -30 ppt; Temperature 29-300C; Ammonia <0.05 mg/l; DO > 4.5mg/l; alkalinity 130-150ppm). The post larvae were fed on starter feed with eight times a day. Commercially available probiotics and minerals were given daily so as to enhance the growth of PL. The post larvae were carefully monitored throughout the 30 days culture period.
At the end of 30 day holding, the seeds could achieve pronounced weight gain (0.4-0.5g) and the survival, which ranged from 60 -85% in various holding tanks. Among the tanks, the maximum survival (75-85%) was found in N5 & N6 tanks and minimum survival (60-70%) in rest of the tanks. Subsequently, the seeds were introduced to grow outs. The study demonstrates that nursery method enhances maximum survival and growth rate, reduced infections and diseases outbreak besides minimum unit cost production. Therefore, nursery technique could be more efficient method and can be advocated to shrimp farming industry.