Coastal Aquaculture and Mariculture (2+1)

Unit 2 - Traits of important cultivable species

2.3. Pearlspot
The pearlspot Etroplus suratensis is an important cichlid fish distributed in India, Sri Lanka and Pakistan. It is found in estuaries, tidal creeks, lagoons, backwaters and swamps. It attains a length of more than 30 cm and weight of about 1.5 kg.

Distinctive characters
Body is oblong, compressed and elevated. There are small teeth on jaws, none on the palate. The dorsal fin is single, with spinous portion greater in extent than the soft portion. Lateral line present in the upper fourth of the body. Colour light green, with eight oblique bands on the body. Most of the scales have central white pearly spots. The dorsal, caudal, ventral and anal fins are dark coloured, pectoral yellowish with a black base. Strong spines on dorsal and anal fins present.

Biology
It matures within one year of its life and breeds in confined waters such as ponds, almost throughout the year. Natural breeding grounds have weeds with water depths ranging from 50-100 cm. A female releases up to 6,000 eggs at a time. The eggs are attached to submerged objects like stones, twigs, tiles, bamboo poles etc. by the female after cleaning them. The male fertilizes the eggs and the female guards over them during development and hatching.

The early fry feed on zooplankton, the advanced fry on aquatic insect larvae. Juveniles and adults feed on filamentous algae and other weeds. Since this fish is easy to breed and a herbivore, it is one of the ideal species for coastal aquaculture.

Etroplus suratensis