The Lambchop Rasbora is a beautifully proportioned small rasbora native to the forest streams and peat swamps of Thailand and peninsular Malaysia. It grows to approximately 4 cm and is distinguished from its close relative the Harlequin Rasbora (Trigonostigma heteromorpha) by its slimmer, more elongated body shape, warmer copper to orange-gold base coloration, and a distinctively shaped dark marking that narrows toward the front in a shape resembling a lambchop or teardrop — hence the common name. This marking is smaller and more posteriorly positioned than in the Harlequin, giving the Lambchop Rasbora a slightly more refined appearance. Like all Trigonostigma species, the Lambchop Rasbora is a schooling fish that should be kept in groups of eight or more, in which it shows natural shoaling behavior and reduces individual stress. It is wholly peaceful and poses absolutely no risk to any tankmates. Originating from warm, soft, acidic blackwater environments, it shows its richest golden-copper coloration in water that approximates these conditions. It is an undemanding omnivore that accepts all small aquarium foods. The Lambchop Rasbora is a rewarding and underappreciated nano species that deserves wider recognition alongside the more commonly kept Harlequin Rasbora.
