Influences of initial delay of feeding on growth and survival of larval redtail catfish, Mystus wyckioides

Influences of initial delay of feeding on growth and survival of larval redtail catfish, Mystus wyckioides
ผลกระทบจากการเลื่อนการเริ่มต้นให้กินอาหารต่อการเจริญเติบโตและอัตราการรอดตาย ของลูกปลากดคัง

Thumronk Amornsakun, Asst. Prof., D. of Tech. and Industries, F. of Sci. and Tech., PSU.
E-mail : thumronk@bunga.pn.psu.ac.th

Published : Songklanakarin J Sci Technol 2000, 22(1) : 51-55
Key words : starvation, delay of feeding, red-tail catfish, Mystus wyckioides

A starvation experiment was carried out using a 15-liter aquarium (water volume 10 liters) with three replications. Two hundred newly hatched larvae of red-tail catfish were kept without feeding. Larvae started to die at 146 hr and totally died within 190 hr after hatching at water temperature ranged between 27 to 30oC.

The influences of initial delay of feeding on survival and growth were conducted through six test groups. The groups were divided at one day intervals from start of feeding (3 days old larvae) up to 5 days of starvation time (8 days old larvae). The larvae were fed with Moina at a density of 5-10 ind/ml. The average percentage of surviving larvae from start of feeding (D0), start of feeding delayed one day (D1), start of feeding delayed two days (D2), start of feeding delayed three days (D3), start of feeding delayed four days (D4) and start of feeding delayed five days (D5) were 92.5, 91.0, 90.0, 90.0, 85.0 and 76.6%, respectively. The average survival rates of larvae from D4 and D5 were highly significantly (P<0.01) lower than those fed at D0, D1, D2 and D3. The average survival rate was not significantly different (P>0.01) between fish in D0, D1, D2 and D3. The average total length of larvae from initial feeding at D0, D1, D2, D3, D4 and D5 were 3.25, 3.05, 3.03, 2.85, 2.85 and 2.63 cm, respectively. Average total lengths were from D0 were highly significantly (P<0.01) greater than those fed at D1, D2, D3, D4 and D5.

It is suggested that larval red-tail catfish should be fed with Moina within 3 days after hatch- ing to ensure better survival and growth.

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