Combtail Gourami

The combtail gourami, Belontia signata, is endemic to the fast-flowing rivers and streams of Sri Lanka, where it inhabits shaded, well-oxygenated waters unlike the stagnant habitats favored by many other gouramis. Its common name refers to the delicate, comb-like extensions along the edges of its dorsal, anal, and caudal fins, most pronounced in mature males. Larger and more robust than dwarf gourami species, it has a reputation for territorial and semi-aggressive behavior, particularly toward conspecifics and similarly shaped fish. It still possesses the labyrinth organ typical of anabantoids, letting it supplement gill respiration with atmospheric air. It remains a distinctive, if lesser-known, member of the gourami family in the aquarium hobby.

• Deep, laterally compressed oval body in reddish-brown to olive with subtle darker mottling or barring
• Fine, comb-like fringing along the edges of the dorsal, anal, and caudal fins, most developed in adult males
• Small dark spot often present near the gill cover
• Pointed snout with a moderately upturned mouth
• Larger and more robust body shape than dwarf gouramis such as Trichogaster lalius
• Distinguished from the related Java combtail by finer scale and fin details and distinct native range

The combtail gourami is endemic to Sri Lanka, where it inhabits clear, well-oxygenated streams and rivers in forested lowland and hill regions, a notable contrast to the stagnant swamps favored by many gourami relatives. It prefers moderate current, rocky or gravel substrates, and overhanging vegetation providing shade and cover. Populations are found in both slower pools and faster riffle sections of river systems across the island's wet zone. Habitat degradation from deforestation and water pollution has reduced suitable habitat in parts of its range, though it remains relatively widespread within Sri Lanka's freshwater systems.

Combtail gouramis are omnivorous and opportunistic, feeding on insects, small invertebrates, algae, and plant matter picked from rocks and vegetation. They are more active and assertive than many smaller gourami species, with males defending territories and often behaving aggressively toward other males or similarly shaped fish, especially during breeding season. Like other anabantoids, males construct bubble nests at the water's surface, typically tucked beneath overhanging leaves or debris, and guard the eggs and fry closely after spawning. Outside of breeding, individuals tend to be solitary or loosely associated, using their labyrinth organ to supplement oxygen uptake in warmer, slower stretches of their stream habitat.