The lsraeli Joumal of Aquaculture - Bamidgeh 49(4), 1997, 205-213

EFFECTS OF LIVE FOODS, ARTIFICIAL FEED
AND THEIR COMBINATION ON GROWTH AND SURVIVAL OF
AFRICAN CLARIID CATFISH (HETEROBRANCHUS LONGIFlUS
VALENCIENNES, 1840) LARVAE


Paul O. Ajah

Institute of Oceanography, University of Calabar, Calabar, Nigeria

(Received 5.9.96, Accepted I8.11.97)

Abstract

In both laboratory and outdoor culture environments, Heterobranchus longiflilis larvae fed a combination (Diet 1) of mixed live zooplankton and artificial diet grew significantly longer (p<0.01 ) than those fed mixed live zooplankton (Diet 2) or an artificial diet (Diet 3: 0.5 mm particle size) alone.

Those fed the zooplankton grew significantly longer (p<0.01 ) than the larvae fed the artificial diet. Larvae fed Artemia nauplii (Diet 4) were significantly longer (p<0.01) than larvae fed Diets 1,2 and 3 on both the 6th and 11th days of culture. The overall best biomass (8.3 g) was obtained by larvae fed Diet 1 followed by Diets 2 (4.9 g), 3 (2.1 g) and lastly 4 (2.0 g). At day 11, the best individual growth (3.4 cm, standard length; 0.47 g wet weight) was recorded among larvae fed Diet 4, followed by 2.1 cm and 0.13g for Diet 1, 1.5 cm and 0.06 g for Diet 2 and 1.3 cm and 0.04 g for Diet 3. Specific growth rates were 4.8%, 34.8%, 28.3% and 23.1% for larvae fed Diets 4, 1, 2 and 3, respectively. The decrease in survival from day 6 to 11 was 98% to 79%; 76% to 65%; 73% to 61% and 28.25% to 4.25%, for diets 2, 1,3 and 4, respectively. In the outdoor culture, larvae fed Diet 1grew significantly longer and had a higher SGR than those fed Diets 2 or 3.


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