Catla fish, scientifically known as Catla catla, is a freshwater fish species native to the Indian subcontinent. It belongs to the carp family Cyprinidae and is one of the most economically important freshwater fish in South Asia. Here's a description of the Catla fish:

1. Appearance: Catla fish typically have a deep and laterally compressed body with a slightly arched head. Their coloration varies from silver to greyish on the dorsal side, fading to a whitish belly. The scales are relatively large and prominently visible. They have a forked caudal fin and a deeply forked mouth.
2. Size: Catla fish can grow to considerable sizes, with adults commonly reaching lengths of up to 1 meter or more. They can weigh anywhere from a few kilograms to over 30 kilograms.
3. Habitat: Catla fish are predominantly found in freshwater habitats, particularly in large rivers, lakes, reservoirs, and ponds with abundant vegetation. They prefer warm waters and are often found in slow-moving or stagnant waters.
4. Diet: Catla fish are omnivorous and primarily feed on plankton, algae, aquatic plants, and small invertebrates. They are filter feeders, using their specialized gill rakers to sieve tiny organisms from the water.