Harlequin Rasbora (Trigonostigma heteromorpha)

This is a relatively small fish and a member of the Cyprinidae family. Before being named the harlequin rasbora, it was referred to as the Rasbora heteromorpha. In Greek, heteromorpha means differently shaped. In terms of body shape, the harlequin rasbora differs from other member of the Rasbora genus.


Geographical Distribution
The harlequin rasbora is a species native to Singapore, southern Thailand, Malaysia and Sumatra. It usually inhabits water bodies such as streams and rivers.

Description
The harlequin rasbora has a lozenge shape with an orange-pink basal color that stretches from its caudal peduncle to the head. Its overall color differs depending on the water conditions in which it lives. This fish has a black marking on the posterior half of its body. The dorsal, anal and caudal fins have a red tint. When fully mature, the harlequin rasbora attains a length of 5 cm.

Habitat
The harlequin rasbora frequents areas with low mineral content and dissolved humic acids. Such conditions are usually found in peat swamp forests. Also this type of fish easily adapts to different conditions. It prefers waters with a pH level of 6.0 to 7.8 and water hardness of around 15 degrees dGH. In terms of temperature, a range of between 22 and 27 degrees Celsius is excellent for this species.

Shoaling
Being a shoaling fish, the Harlequin rasbora prefers moving in groups of about 6 individuals. However larger groups can also be cited from time to time. For the aesthetic value, most fish keepers prefer larger shoals.

Behavioural Tendencies
This fish species is relatively peaceful and as such coexists with other fish varieties without any harassment and aggression. Some of the fish species that may be grouped together with the harlequin rasboras are danios, Otocinclus catfishes, Corydoras catfishes among others.

Reproduction
The Harlequin rasbora females usually deposits adhesive eggs on the undersides of leaves. The eggs are then fertilized by the males who follow closely. Every deposit contains about 6 to 12 eggs. Maturity for the young Harlequin rasboras takes about 8 to 10 weeks.