Esomus

E. caudiocellatus can be told apart from congeners by lacking a dark lateral stripe and possessing a prominent dark marking on the caudal peduncle. In recent years a number of phylogenetic studies involving Esomus and its near relatives have been conducted and conflicting results published. For example a 2003 study by Fang et al. concluded that the genus is the sister group, i.e., most closely-related to...

Found in various types of habitat but shows a marked preference for shallow, slow-moving and standing waters such as rice paddies and other temporally-inundated environments with dense aquatic vegetation.

Known from the Mekong river basin in Thailand, Laos, Cambodia, and Vietnam, the Tonlé Sap river and lake system in Cambodia, and smaller, coastal drainages in southeast Thailand. Records from Peninsular Malaysia are likely to refer to other species. Type locality is given simply as 'Cambodia'.

There currently exist a dozen described Esomus spp. alhough few are seen in the aquarium trade and none are especially popular. Most are commonplace in their native countries and also quite plainly-patterned so generally overlooked by collectors. Their most common use in some areas is actually as a feeder fish in the aquaculture of larger species. They're characterised by greatly-enlarged pectoral fins and two pairs of barbels, of which the maxillary pair are extremely long and usually reach the pectoral fins.