Shellfish Breeding and Hatchery Management (2+1)

Estimations in the hatchery designing for shellfishes

1. Estimate and provide your suggestions for the following situation:

Target – 1.0 million juveniles; Stocking density – 100 PL / sq.m; Possible survival – 75% ; Quantity of feed to be used – 1 kg per 1000 PL per week.; period of rearing – 30 days

Estimate the total feed requirement, area required for rearing and no. of cycles to be done in a year

2. Estimate and provide your suggestions for the following situation:

Target – 2.0 million juveniles; Stocking density – 200 PL / sq.m; Possible survival – 80% ; Quantity of feed to be used – 1 kg per 1000 PL per week.; period of rearing – 30 days

Estimate the total feed requirement, area required for rearing and no. of cycles to be done in a year.

3. Give the design requirements for the following and list out the components and their capacities:

a) Plan for a shrimp hatchery of 40 million PL per annum

(Considerations: Species: P. monodon, Size of brood stock – 100g, Fecundity - 1 million eggs per brood stock, Spawning rate - 85%, Nauplii stocking density – 500 nauplii per l of water, Nauplii survival rate – 40%, larval rearing period – 15 days a cycle, Crop break – 4 days)

b) Plan for a prawn hatchery of 3 million PL per annum

(Considerations: Species- M. rosenbergii, Brood stock size – 60g for female and 150g for male, Fecundity – 900 eggs/g, Spawning rate – 80%, Larvae survival rate – 30%, Larval cycle – 30days, Crop break – 10 days, Larvae stocking density - 100 larvae/l)

c) Plan for a nauplii rearing facility to yield 100 million PL per annum. Estimate the total water requirement if the water exchange rate is 20% a day for first 5 days, 30% a day for next 5 days and 50% daily for next 2 days.

(Considerations: Area available – 100 sq.m., Crop failure possibilities – 20%, Stocking density – 400 nauplii/l, Larval rearing period – 12 days, Crop break – 3 days, Nauplii survival rate – 50%)

Plan for a Juvenile production unit for the production of 4 million Juvenile per annum with the water requirement if 30% water exchange is done every day.

(Considerations: PL stocking density – 100/sq.m, Rearing period – 30days, No crop break, survival rate – 80%, Area available 1000 sq.m)

d) Plan for a shrimp hatchery of 40 million PL per annum

(Considerations: Species: P. monodon, Size of brood stock – 100g, Fecundity - 1 million eggs per brood stock, Spawning rate - 85%, Nauplii stocking density – 500 nauplii per l of water, Nauplii survival rate – 40%, larval rearing period – 15 days a cycle, Crop break – 4 days)

e)Plan for a prawn hatchery of 3 million PL per annum

(Considerations: Species- M. rosenbergii, Brood stock size – 60g for female and 150g for male, Fecundity – 900 eggs/g, Spawning rate – 80%, Larvae survival rate – 30%, Larval cycle – 30days, Crop break – 10 days, Larvae stocking density - 100 larvae/l)

f) Plan for a nauplii rearing facility to yield 100 million PL per annum

(Considerations: Area available – 100 sq.m., Crop failure possibilities – 20%, Stocking density – 400 nauplii/l, Larval rearing period – 12 days, Crop break – 3 days, Nauplii survival rate – 50%)

g)Plan for a Juvenile production unit for the production of 2 million Juvenile per annum

(Considerations: PL stocking density – 100/sq.m, Rearing period – 30days, No crop break, survival rate – 80%, Area available 1000 sq.m