Harlequin rasbora
Trigonostigma heteromorpha
4 cm
Adult size
60 L
Minimum volume
10
Minimum group
5 years
Lifespan
Water parameters
Understand these values- Genus
- Trisgonostigma
- Diet
- carnivore
- Social life
- shoal
In the wild
Overview
Described in 1904 by the German ichthyologist Georg Duncker, the harlequin rasbora has a black triangular patch on the rear of its body, which gave its name to the genus Trigonostigma (“triangle mark”), split from Rasbora by Maurice Kottelat and Kai-Erik Witte in 1999.
A DNA barcoding study (2012) detected two distinct genetic lineages among fish in the trade, suggesting that the current species may include several. Blue, black and golden captive-bred forms exist.
- Scientific name
- Trigonostigma heteromorpha (Duncker, 1904)
- Classification
- Cypriniformes › Danionidae
- IUCN Red List
- Least concern (LC)
Natural habitat
Malay Peninsula: Malaysia, Singapore, the far south of Thailand, Sunda Islands (Sumatra, Borneo)
Observations (GBIF) and localities Native countries Rivers and lakes
Its type locality is Kuala Lumpur. It is found on the Malay Peninsula, notably in the peat swamp forests of Selangor, Kelantan, Terengganu, Pahang and Johor states, in Singapore in the Nee Soon swamp, and in Narathiwat district in Thailand.
It frequents the calm parts of forest streams where dense beds of Cryptocoryne grow. The water, soft, slightly acidic and often stained by tannins, is dimly lit under the canopy; in peat swamps it forms shoals of more than a hundred fish.
Behaviour
Very peaceful, it is an ideal choice for beginners and for a community aquarium of small fish, including shy anabantoids. A shoaling fish, it is kept in a group of at least 8 to 10.
A micropredator, it feeds on small insects, worms and zooplankton. Its spawning is unusual: the pair turns upside down under a broad leaf and sticks its eggs there, with no parental care. In the male, the black triangle is sharper and its front edge reaches down to the belly.
Sources:FishBase Seriously Fish GBIF · Base map: Natural Earth