​Early Weaning of Asian Stinging Catfish, Heteropneustes fossilis (Bloch) Larvae

Abstract

Background: Heteropneustes fossilis commonly known as stinging catfish is a popular indigenous fish of the Indian sub-continent. The species has a high consumer demand because of its tender flesh, low fat and high iron content, and is recommended for anaemic patients. Although the species has high consumer preference and potential for commercial aquaculture but, high mortality of larvae and difficulties in accepting compound diet during larviculture are some of the major bottlenecks. Keeping this in mind, the present study was designed to determine the earliest age at which stinging catfish can be weaned to an artificial diet. The information generated from the present study would be very helpful in improving survival during larval rearing. Methods: The larvae were randomly distributed @ 60 larvae/ tank in 21 circular FRP tanks containing 30 L water each and the feeding experiment started at 2 dph. Seven different feeding strategies depending on the type of food (zooplankton, Artemia nauplii, or microdiet) and the age at which those food items were provided to larvae, were evaluated. Result: The results indicated that larvae survival in the groups weaned after 5 days post hatch (dph) was similar to that of those fed solely with Artemia nauplii and zooplankton, although growth of larvae in the weaned groups was less. As larval growth can be compensated at later stages of the rearing process, therefore, larval survival is considered as one of the most important parameters for evaluating the weaning success. Based on the present findings, it is suggested to rear stinging catfish larvae with zooplankton without dependence upon costly Artemia nauplii, and larvae may be weaned to artificial diet after 5 dph. The findings would be very helpful for improving larval rearing of this indigenous catfish species in Indian rural areas.