Indian Major Carps (IMC):

Catla (Catla catla): Is a deep bodied fish with a conspicuous head, large upturned mouth, non-fringed lips without barbels. It is generally known as a surface feeder. Naturally feed on zooplankton using gill rakers. Under culture condition feeds on formulated floating feed. It is the fastest growing fish among IMC. It can grow to a maximum size of 1.8 m (45 Kg). In ponds it can grow upto 1.5 to 2 kg in first year. It attains sexual maturity only in second year. It breeds naturally in rivers during rainy season. Commercial artificial seed production done by induced breeding in carp hatcheries. Eggs are non adhesive floating. Highly suitable for culture in large ponds above 10 cents (0.04 ha) with other IMC and Chinese carps.

Rohu (Labeo rohita): It has a small and pointed head, terminal mouth with fringed lower lip. It also has dull reddish scales on body. It is a column feeder. It naturally feeds on phytoplankton, plant debris of aquatic plants. Under culture condition it feeds on formulated floating feed. It is considered as tastiest fish among all carps. In ponds it can grow upto 900 g in first year. The maximum reported size is 1m. Its Sexual maturity, breeding, seed production and culture are similar to catla.

Mrigal (Cirrhina mrigala): A linear body having small head and blunt snout, sub-terminal mouth with thin non fringed lips. It has a bright silvery body having golden tinge. It’s a bottom feeder feeds on decaying organic vegetation naturally. In ponds it can grow upto 700 g in first year. The maximum reported size is 0.9m. Its Sexual maturity, breeding, seed production and culture are similar to catla. and rohu. The normal recommended stocking ration of Indian major carps is 4:3:3 ( Catla: Rohu: Mrigal)

Chinese carps:

Grass carp: Ctenopharyngodon idella: It has an elongated body, broad head with rounded snout, slightly longer upper jaw, moderately sized scales with light greenish tinge. Normally it feeds on aquatic weeds and terrestrial grass. It is known to control submerged aquatic weed like hydrilla. It defecates 50 percent of daily food consumed in a semi digested form which acts a fertilizer for plankton production. The maximum reported size is 1.5 m (30 Kg). Its growth is very fast in first year and can reach up to 3 kg. The fish should be provided with aquatic vegetation or chopped grass for good growth. It attains sexual maturity only in second year.  Commercial artificial seed production done by induced breeding in carp hatcheries.

Common carp (Cyprinus carpio): It has a deep body and short head. There are different varieties and strains of common carp which have different shape from elongated to deep oval. Their colour also varies from gray, silver to bronze with a yellowish or reddish belly. The mouth is large and opens downwards. There are two pairs of barbels, one pair on the upper lip and the other pair at the corners of the mouth. They can tolerate wide temperature range of 3–35 ^oC. They are omnivore’s generally occupying middle and lower sections water and eat larvae of insects, worms, mollusk to submerged plants in natural water. They very well accept formulated feed. The improved varieties can grow 1-1.5 Kg in a year. The maximum size reported is 6 kg. They mature within a year and can breed in pond naturally without any inducement. One of the latest improved varieties released in India is known as Amur carp.

Air breathing fishes

Magur (Clarias batracus): Known as Mushi in Malayalam. Its body is elongated and compressed with rounded abdomen. Head is depressed and covered with bony plate which has 4 pairs of barbells. They are omnivorous; it feeds on smaller fish, mollusks, other invertebrates, as well as detritus and aquatic weeds. They are highly suitable for culture in shallow ponds and tanks. It can grow upto 0.5 m in length weighing 1.2 kg. Its counterpart African cat fish C. gariepinus has faster growth rate reaching to a max size of 60 kg. Due to its predatory habit it is banned for culture in India and is considered harmful and invasive.

Singhi (Heteropneustes fossilis): Known as Karri and Kadu in Malayalam. It has elongate and compressed body with moderate size head having 4 pairs of barbells. It has a rounded caudal fin and its pectoral fins have serrated spines hence are known as stinging cat fish. It grows up to 1ft. Feeding and culture is similar to that of magur. It’s suitable for monoculture but its culture is not well established in Kerala.

Murrels or Snake head (Channa sp.)There are different species of snake head commonly known as varal / braal in Malayalam. The most common cultured one is Channa striatus. Dorsal and anal fins of this species are long and without spines. It can reach up to 90 cm in length. Adults are dark brown in colour with faint black bands, visible across its entire body.  The young ones (fry) are reddish orange in colour and are guarded by parents until they turn greenish brown colour ie. around 5–6 cm. They are carnivores and mostly feed on small fishes, tadpoles, frogs etc. under culture they require high protein formulated feed having more fishmeal. It’s a high value fish but its culture has not picked up due to scarcity of seed and suitable feed. It’s suitable for mono culture in small ponds and tanks.

Pangus (Pangasius hypophthalmus)It’s a widely cultured air breathing fish globally and in India. Its commonly referred to as tiger shark in aquariums, basa in north India and vaala ( Asam vaala, Malaysian vaala etc.) in Malayalam. It has a long body, latterly flattened with no scales. Has a small head with broad mouth having 2 pairs of barbels.  It’s an omnivorous which naturally feeds on algae, higher plants, zooplankton, and insects, while larger fishes also take fruit, crustaceans and small fish. It can reach to a maximum length of 130 cm weighing 44 kg. It can attain 1kg in 8-10 months under culture conditions when fed on formulated feed but shows differential growth. Its Age at maturity is 2 years for male and 3 for female. It’s widely culture in India in large ponds and even in small tanks. Its culture is picking up in Kerala though its consumer preference less in the state. A license has to be obtained from Fisheries Dept for taking up its culture. In supermarkets its fillet are sold by the name basa fillets.

Anabas (Anabas testudineus): It is also referred as climbing perch or climbing gouramies locally they are known as karuup or kaitha kora in Malayalam. It can utilize atmospheric oxygen and can remain out of water for 6-8 hrs. It can tolerate wide range of pH. Due to his hardy nature it’s been cultured under high stocking densities. It’s also known to have medicinal values. In the wild, Anabas species grow up to 30 cm (1 ft) long. They are carnivorous; living on a diet of water invertebrates and their larvae. They also accept formulated feed. Under culture conditions they attain 200-250g in 10 months. Another species Anabas cobojius has a better growth rate.

Other commercially important freshwater fishes

Nile tilapi (Oreochromis niloticus): Has distinctive regular vertical stripes on the body and on caudal fins. The fish grows to a maximum size 60 cm in length and weighs 4.3 kg. It’s a hardy fish which can tolerate wide range of temperature and salinity.  It is an omnivore that feeds on plankton as well as on higher plants in nature. It very well adapts to intensive culture systems and feeds on formulated floating feed. In can attain 500g in 6-8 months. The males grow faster than female hence all male tilapias are preferred for culture (MST- mono sex tilapia). Improved strains of this tilapia developed by selective breeding are available such as GIFT (Genetically improved farmed tilapia) Chitralada from Thailand etc. It performance well when cultured alone (monoculture) in tanks, small ponds without or with RAS and also in larger ponds. Its farming requires license from district fisheries Department.  Nile tilapia has better growth rate than Mossambic tilapia (O. mossambicus) which was introduced earlier in India.

Pacu (Piaractus brachypomus): It is generally known as red-bellied pacu and in Kerala as nutter and “Akoli macchan” due to its resemblance with pomfret (Akoli in Malayalam). In aquarium shops the fish is wrongly called as piranha (Pygocentrus nattereri) which is a carnivore having pointed sharp teeth when compared to pacu which has flat molar like teeth. This fish attains sexual maturity only at 3 years of age. It is one of the fastest growing fish that can attain a marketable size of 350-500g in 6-8 months time, even in tanks and small ponds. Its maximum reported size is 25 Kg. The fish accepts all kinds of feed and fetches high selling price. Hence it has been a fish of choice for all aqua farmers but it culture is still not approved in India

Contributor: Dr. B. Pradeep, Subject Matter Specialist- Fisheries, ICAR-Krishi Vigyan Kendra,ICAR-IISR, Peruvannamuzhi, Kozhikode 673528 Kerala, Email: pradeep@spices.res.in