Amblyrhynchichthys micracanthus

Amblyrhynchichthys: from the Greek amblús (Gr. ἀμβλύς), meaning 'blunted', rhýnchos (Gr. ῥύγχος), meaning 'snout', and ichthýs (Gr. ἰχθύς), meaning 'fish', in allusion to the comparatively blunt snout in members of this genus.

micracanthus: from the Greek mikrós (Gr. μικρός), meaning 'small' and ákantha (Gr. ἄκανθα), meaning 'thorn', in reference to this species' relatively short dorsal spine when compared to the congener A. truncatus.

Native to the Mekong River catchment in Laos (where Vientiane province represents the upper limit of its range), Thailand, Cambodia, and Vietnam, and the Tapi, Chao Phraya, and Mae Klong river systems in Thailand.

Type locality is '22 kilometers upstream from Phnom Penh, Tonle Sap River, Kandal Province, Cambodia'.

A riverine species which also moves into areas of inundated forest during the wet season (June to September), while juveniles have been observed in swamps and flooded fields.

Wild fish feed on periphyton, phytoplankton, zooplankton, and benthic algae.

Prior to this species' description, the genus comprised only a single species meaning older records of A. truncatus in mainland Indochina all refer to A. micracanthus.

A. micracanthus can be told apart from A. truncatus by the following combination of characters: snout more truncate with a straight (vs. gently rounded in A. truncatus) lateral profile; dorsal-fin spine shorter, measuring 15.5-25.7% SL (vs. 26.7-29.9%); a smaller eye when individuals of a similar size and larger than ca. 70 mm2.8 in SL are compared, with a diameter measuring 28.7-34.9% HL (vs. 32.7-36.3%); 34-37 (vs. 39-40) gill rakers.

The genus Amblyrhynchichthys is distinguished from all other cyprinids by the following character combination: snout extremely blunt; nostrils located anteriorly; last simple dorsal-fin ray stout with serrations on the posterior edge; presence of a well-developed, hyaline eyelid.