Shellfish Breeding and Hatchery Management (2+1)

18.2.1 Feeding rate of Artemia nauplii to freshwater prawn larvae

Age of larvae (d)	Larval stage	No. of Artemia nauplii/ larvae/ day
3	II-III	5
4	II-III	10
5-6	III-IV	15
7-8	IV-V	20
9	IV-VI	30
10-11	V-VII	35
12	VI-VII	40
13-14	VI-VIII	45
15-24	VII-PL	50
25-30	VIII-PL	40
31-35	IX-PL	30

Feeding starts from 2^nd day of hatching. Prepared feed are usually given in the day time, Artemia nauplii in the night time. Different stages require 50 to 150 µg prepared feed/ larvae/ day and Artemia nauplii from 5 to 50 per larva/ day.

Brine shrimp nauplii are given in the night to ensure the presence of food in the larval rearing medium throughout night. While inadequate feeding leads to started growth due to strarvation, cannibalism and prolonged metamorphosis over feeding leads to water pollution. The larval rearing tank is to be cleaned every day, by siphoning out feed residues, metabolic waste and faecal matter from the bottom of tank. This is to be done daily after stopping aeration before water exchange and feeding of Artemia nauplii.

PL-3 to PL-6 stage Artemia nauplii given @ 2 nauplii/ml 3 times daily. PL-7 to PL-12 – 3 nauplii/ml, 3 times daily. PL-13 to PL-20 – 3 nauplii/ml once daily. While adding Artemia nauplii care must be taken to avoid cyst shell as it may bring bacteria into the rearing medium.

In addition to Artemia nauplii, artificial feed is also given such as microencapsulated feed and egg custard. Microencapsulated feed is dissolved in water, stirred and allowed to stand for 5-10 minutes. The feeding is done @ 0.5 g/ton.