Freshwater Fish in Colombo Wetlands

Green cromide ( Etroplus suratensis )

Green cromide is a native fresh water fish species in Sri Lanka belongs to Cichlidae family. This species has laterally compressed deep body. Dorsal side of this fish is dark greenish brown, becoming lighter laterally. Ventrally it is white, mottled with dark gray spots in juveniles, and black in adults. Six to eight vertical bars can be observed on the sides. Scales behind the operculum have greyish white spot which provides jewelled effect and giving this species a majestic appearance. In addition to that few random black spots are present on the lower body of the adults. Dorsal, pelvic and anal fins are dark greyish brown. The outer edge of the caudal fin is white and there is a dark spot at the base of the pectoral fin. Males bear dark colours while females bear lighter colours. Adults can grow up to 24 cm in length.This species prefer to live as small schools and found wide range of habitats including rivers, tanks, marshes, mangroves and wetlands. Since this species is considerably hardy fish and has wide range of distribution IUCN listed as least concern species. Green cromide is popular as food and aquarium fish species.

Flying barb (Esomus thermoicos)

Flying barb is a native fish species to Sri Lanka belongs to Cyprinidae family. It has a slender elongated body with an olive grey dorsal aspect, becoming silvery across the lateral side with a dark blue band running along the body from the operculum to the hypural. The upper margin of this band is sharp and the lower has a more saw-like pattern. Either sides of this band there are fine yellow lines. Long pair of barbels extends up to anal fin. The caudal fin of male is yellow, bright in colour while the dorsal, anal, pectoral and pelvic fins are transparent with a yellow blue tint. This species can grow up to 6cm. Commonly found in tanks rivers, canals and wetlands. This species prefer moderately flowing water. Since this species has wide range of distribution it is considered as none threatened least concerned species.

Sri Lanka Day’s Killifish (Aplocheilus dayi)

The Day’s Killifish has small elongated body which can grow up to maximum length of 5cm. This species is endemic to Sri Lanka and can be found in streams, rivers, tanks and wetlands. However this species prefer heavily shaded habitats. Its dorsal side is olive green in colour. Laterally acquires a greenish yellow, with rows of bluish green spots. Among these spots, few randomly placed red and black dots can be seen. Ventrally it is yellowish white in colour. Sharply pointed anal and pelvic fin membranes are yellow and fin rays appear in bright orange colour. Caudal and dorsal dorsal fins are yellow and mottled with bright orange. A white colour spot is present on the vertically compressed head and that gave the Sinhala name is “Uda Handaya”. Males show bright colours while females are dull in colour with six to seven black colour vertical bars on the sides. Mouth is superior and it upward directed

Sri Lanka Walking Catfish (Clarias brachysoma)

Sri Lanka walking catfish is a fresh water fish species belongs to family Clariidae. It is endemic to Sri Lanka. Its natural habitats are rain forest streams, lowland rivers and wetlands.

This species has vertically compressed head and flat wide mouth. Four pairs of barbules present around the mouth. Elongated body is horizontally compressed like a thick ribbon. Body colour is varying from brown to dark brown and malted pattern observed all over the body. Dorsal fin is started just behind the head and extends towards caudal peduncle and this feature can be used to separate this species from sting catfish (Heteropneustes fossilis).

During the wet season it often enters ephemeral flooded habitats where it may become trapped as waters recede. If necessary it’s able to travel across land for distances of several hundred metres using its pectoral fins and this gave the name walking catfish. It grows to a length of 40 cm. During mating season, spawning occurs in nests among weeds in very shallow water. Then the male guards the nest and young until reaching about 1 cm in length.

However this species is threatened by habitat loss, wetland degradation and hybridization and competition with invasive species marble catfish