Endemic to the middle and lower Mekong River system in Laos, Thailand, Cambodia, and Vietnam. Its known range extends from Chiang Rai province, Thailand in the north to Kratie province, Cambodia in the south, and it occurs in several important tributary systems including the Sesan, Srepok, and Tonlé Sap.

Type locality is ‘Mekong River at Kemarat, Thailand’.

There is a fish of unknown geographical origin which matches the majority of diagnostic features for L. setigerum with the exception that the dark lateral stripe is absent in the anterior portion of the body and is not composed of interconnected spots. It is relatively common in the aquarium trade and included here as L. cf. setigerum until a confirmed identity is established.

L. bleekeri is most-easily distinguished from the congener L. setigerum, with which it is frequently confused, by absence (vs. presence) of a series of black spots on the lateral line scales.

The majority of Lobocheilos species are endemic to the Greater Sunda Islands of Borneo, Sumatra, and Java, and are uncommon in the aquarium trade, but the widespread Indochinese taxa L. melanotaenia and L. rhabdoura are available on a sporadic basis.

L. melanotaenia can be distinguished from L. rhabdoura by the following comb…

This species can be distinguished by the following characters: juveniles with brown body and dark marking at base of caudal-fin; 37-42 + 3-4 lateral line scales; 11½ branched dorsal-fin rays; 7½ scale rows between lateral line and dorsal-fin origin; 20-25 predorsal scales; dorsal-fin relatively small with anterior branched rays shorter than head in juveniles, slightly longer than head in adults.

The monotypic genus Incisilabeo is separated from the closely-related taxon Bangana by presence of a unique and conspicuous transverse notch across the top of the head, comparable in position to the ethmoid furrow in Bangana species. This notch approaches the eye, and the top of the head bulges forward, with the nostrils located partially beneath this projection and immediately anterior to the eyes. Tubercles cover the upper portion of the rostral fold, lower part of the notch, and upper surface of the forehead projection…

This species is migratory on a seasonal basis; during the dry season it can be found in larger river channels, whereas during drier months it moves into smaller tributaries and flooded forests.

Apparently displays a preference for rocky habitats and is not known to adapt to reservoirs or other artificial impoundments.

M. opercularis is a classic aquarium fish, having been introduced to the hobby by a French soldier named Gerault in 1869. Of the initial 100 specimens shipped, 22 survived and were successfully bred later that same year by another Frenchman, the Parisian Pierre Carbonnier. This gives the species the distinction of being one of the very first ornamental fish imported to Europe. It is also known as ‘Chinese fighting fish’, ‘paradise gourami’, and ‘blue paradise fish’.