Crossocheilus

This species is among a handful of near-identical congeners that are traded as 'Siamese algae-eater' (often abbreviated to 'SAE'), 'Siamese flying fox' and 'Crossocheilus siamensis'. The latter name is not valid, however, and is a synonym of Epalzeorhynchos siamensis which is itself a synonym of Crossocheilus oblongus, a species described from Java. C. oblongus is currently accepted to...

We've been unable to obtain a diagnosis for this species to date but it can at least be distinguished from those congeners traded as 'Crossocheilus siamensis' (an invalid name synonymous with C. oblongus, which is itself of questionable identity), 'Siamese algae eater', or 'SAE' by the fact that the dark lateral stripe does not extend into the caudal-fin. Members of Crossocheilus are characterised by...

Given its wide natural range it seems logical that this species is or has been available in the aquarium trade, although its correct name may never have been applied. It is told apart from congeners by the following combination of characters: two pairs of barbels; a continuous midlateral stripe from the tip of the snout to the base of the caudal-fin, with a conspicuous small blotch at the posterior extremity, faintly marked on the caudal-fin; a faint mark between the anus and the anal-fin origin in juveniles; a narrow mouth.

This species can be most easily distinguished from other members of the genus by its colour pattern which consists of a blackish midlateral stripe extending from the tip of the gill opening to the middle of the caudal-fin base, which is separated from the dark brown dorsum by a pale yellowish brown stripe. This differs from the pattern seen in other Crossocheilus species with a black midlateral stripe in which the the dorsum is olive brown and much paler than the midlateral stripe, there is no yellow stripe between the dorsum and the black stripe, and the black stripe extends to the tip of the snout.

C. oblongus is another name widely misused in the trade but that species has seemingly never been exported and was described as a blueish fish with yellow fins. It's native to streams of Gunung Salak mountain in Bogor Regency, West Java, Indonesia where collecting of ornamental fishes is almost non-existent. Other species of laterally-striped Crossocheilus also exist and may be available from time-to-time but are more easily told apart from the group described above.

C. latius isn't often available in the trade but makes an excellent alternative to more commonly-offered members of the genus should you be lucky enough to find some. Shipments of similar-looking Indian Garra species such as G. mullya or G. gotyla sometimes contain the odd specimen. It exhibits morphological differences when compared with other members of the genus and may be assigned to a separate taxon at some point in the future.

While separating some of the fish that may be found on sale as 'C. siamensis' is a tricky task, C. nigriloba is quite simple to identify. The dark lateral body stripe uniquely breaks up into a series of blotches when the fish are sparring, stressed or sleeping and the lower caudal fin lobe contains dark pigmentation suffused with red. The latter feature has given rise to the trade name of 'penguin flying fox'.

While some laterally-striped members of the genus look very similar to one another the combination of silvery body, dark-edged scales and dark caudal peduncle blotch set C. reticulatus uniquely apart. The names Crossocheilus tchangi, Epalzeorhynchos coatesi and E. stigmaeus are all now considered synonyms of the species but were erected because the fish vary, most often in minor aspects of patt...