<div>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.&nbsp; 
 
Methods: The larvae were randomly distributed @ 60 larvae/ tank&nbsp;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.&nbsp; 
 
Result: The results indicated that larvae survival&nbsp; 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.</div>

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

<div>Background: Heteropneustes fossilis (Bloch, 1794) is one of the popular freshwater fish known for its food quality and nutritional value. This study was undertaken with an aim to find out histopathological changes in the intestine of freshwater fish Heteropneustes fossilis, host of trematode parasite Masenia vittatusia Agarwal, 1963. 
 
Methods: The intestine of uninfected fish used to determine normal anatomy, while infected intestine to determine pathological changes. The normal histological procedure was followed, which included fixing, rinsing, dehydrating and embedding of tissue. Tissue was cut in 4-6 &micro;m thick sections using a rotary microtome. Haematoxylin and eosin stains were used. 
 
Result: The highest damage was observed in the mucosal layer with ruptured and fused microvilli, hyperplasia of villi, damaged columnar epithelium layer and spread of loose connective tissue into the lumen. Other degenerative modifications included hypertrophy of blood vessels in mucosa and muscularis part, some of them ruptured might be the cause of haemorrhage inside the layers. Other changes include variation in the routine shape of all three layers. The mucosal layer showed aggregation of lymphocytes and mast cells as well.</div>

​The Histopathology of Alimentary Canal of Stinging Catfish Heteropneustes fossilis (Bloch, 1794), Susceptible for Trematodes Incursion

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

​The Histopathology of Alimentary Canal of Stinging Catfish Heteropneustes fossilis (Bloch, 1794), Susceptible for Trematodes Incursion

The Histopathology of Alimentary Canal of Stinging Catfish Heteropneustes fossilis (Bloch, 1794), Susceptible for Trematodes Incursion