Pearl spot (Etroplus suratensis). It is also known as green chromide among aquarium hobbyists’ and as karimeen, chittan, erumeen in different parts of Kerala. This cichlid is the state fish of Kerala. The adult is oval in shape with a short snout, body is grey-green in colour with dark bands and pearl spots. It can grow up to 20 cm length. It’s a highly-priced fish but has a slow growth rate. It reaches only 250-350 g in 8-10 months period. It’s an omnivore which very well accepts formulated feed. It is suitable for culturing in small ponds, cages and pens as mono or polyculture with milkfish, mullet etc. It naturally breeds by laying eggs on a hard substrate and later moves hatchlings to a pit nearby and guards its young ones. It can even breed and grow in freshwater bodies.

Milkfish (Chanos chanos): It is known as poomeen in Kerala. It has an elongated and almost compressed streamlined body with olive green colour, covered with silvery scales. The mouth is small and toothless. It has one dorsal fin and a sizable forked caudal fin. It can grow to 1.80 m ie.14 Kg. It is one of the fastest-growing brackishwater fish attaining 500g size in six months under culture conditions with formulated floating feeds.  It is one of the favourite fish for aquaculture having fast growth rate and with high market value. The main constrain is regarding its seed availability as it naturally breeds in the sea and its larvae come to coastal and brackish water areas with the tide which are mostly collected for culture.  Its commercial hatchery production has just started.

 Mullet (Mugil cephalus): Known as flathead grey mullet and thirutha in Malayalam. It is another high value fish in Kerala which is suitable for aquaculture. Its body cylindrical, robust, head broad having an adipose eyelid covering most of the pupil of the eye, it has two dorsal fins. It can grow to 1m in length. The breeding and culture is similar to that of milkfish. They are sensitive to low dissolved oxygen and are known for their jumping nature. Seed availability is a major problem for aquaculture.

Asian sea bass (Lates calcarifer): Its known as barramundi, bhetki in north India and as Kalanji, Narimeen, Kollon, Kannikayan in different parts of Kerala.  It has an elongated body with a large, mouth. Its operculum has spines. The body is covered with thick scales and has single dorsal having with spines in front and soft rays behind. It is carnivorous in nature feeds on small fishes and shrimps and can grow to a maximum size of 60 kg.  It’s a protandrous hermaphrodite which breeds in the sea. It is breeding and seed production is standardized and hatchery-produced seed is available.  Its cage culture and polyculture with tilapia are standardised. It’s better to grade the fish at least once in 10days during culture especially in initial stages as the fish shows differential growth and cannibalism. Generally it’s cultured using thrash fish (low-value fish) and can achieve more than 1 kg within a year. Specially formulated feed is also available for the fish.

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