The massive decline in wild populations, hypothesised to be in excess of 90% since the mid-1980s, is thought to have been caused by a variety of factors, including habitat alteration due to construction of dams and other infrastructure, removal of riparian vegetation, and urban pollution, plus over fishing for both human consumption and the aquarium trade.

Known from the lower Mekong River basin in Laos, Thailand, Cambodia, and Vietnam, plus tributaries of the Chao Phraya watershed in central Thailand, and drainages between the Chao Phraya and Mekong in eastern Thailand.

Type locality is ‘Nam-Mun at Korat, 135 miles northeast of Bangkok, Thailand’.

It is thought to have been extirpated from the Chao Phraya and Mae Klong rivers, Lake Songkhla, and the entire island of Java due to a variety of anthropogenic factors, and the Mekong populations have also been drastically reduced. In particular, it is sensitive to pollution and gillnetting, and is heavily overfished.

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…

G. siamensis can be distinguished from congeners by the following combination of characters: possession of 5½ lateral line scales; body relatively deep, depth fits 3.2-3.4 times in SL; head large and broad, width fits 5.5-6.7 times in SL; snout not or only weakly projecting; body plain silver in colour with no dark marking on caudal peduncle.

G. ornatapinnis can be distinguished from congeners by the following combination of characters: head small; snout relatively short and blunt; caudal peduncle very deep; pectoral, pelvic, and anal fins usually reddish-orange or rose-tinted; pelvic and anal fins often with white tips; barbels completely absent.

G. lobatus can be distinguished from congeners by the following combination of characters: possession of 32-33 + 2-3 lateral line scales; 5½ scale rows between lateral line and base of dorsal-fin; body relatively slender, depth fits 3.7-4.0 times in SL; snout often projecting strongly; body plain silver in colour.

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

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