Following Roberts (1997) G. ariza can be diagnosed by the following combination of characters: body with variably intense thin stripes dustributed mostly above the lateral line; larger individuals sometimes with a broad midlateral stripe; 32-35 lateral scales; 7-8/1/5-6 transverse scale rows; 8-9 branched dorsal-fin rays 8-9; 22-24+ 11-12=34(4), 35 (3) vertebrae; live colour pattern variable, overall dull dirty white to greyish, silvery or yellow.

This species can be identified by colour pattern comprising a brownish dorsal surface, yellowish flanks and abdomen, and a black to bluish lateral stripe extending from the eye to the caudal-fin base.

This species is endemic to and widespread within peninsular India, where it has been recorded from the states of Gujrat, Madhya Pradesh, Chhattisgarh, Orissa, Jharkhand, West Bengal, Maharashtra, Andhra Pradesh, Goa, Karnataka, Tamil Nadu and Kerala.

It is thus found in numerous river systems of which some of the most important include the Tapti, Narmada, Mahanadi, Godavari, Krishna, and Cauvery.

This species has been collected for the aquarium hobby, albeit in small numbers at time of writing, but its identity is unclear.

Though obtained from close to the type local…

Type locality is given as ‘Cedawáti [Vedawati] stream, headwaters of Krishna River near Heriuru, Mysore, India’, with the species currently considered to occur throughout India, Bangladesh, Nepal, and probably Bhutan.

It’s also been recorded in Pakistan, Myanmar, Thailand and Sri Lanka although some or all of these reports may refer to other species.

This species occasionally appears in the ornamental trade, usually as ‘striped hill trout’ or ‘banded hill trout’.

It can be distinguished from congeners by the following combination of characters: lateral line complete with 40-42 scales; barbels absent; 10-13 anal-fin rays; body with 9-11 dark blue vertical bars; last dorsal-fin ray extending to caudal-fin base.

This species is also referred to as ‘Asian knifefish’ or ‘ghost knifefish’ in the aquarium trade in the aquarium trade but arguably has no place in the ornamental hobby given its adult size and specialised requirements.

It is sometimes confused with the African species Xenomystus nigri but is easily told apart by its larger adult size and presence (vs. absence) of a dorsal fin.

This species’ name has been widely misapplied in the aquarium trade and hobbyist literature, most often in reference to the Southeast Asian species C. ornata, but unlike its relative is in fact very rarely exported for ornamental purposes although its is fished and cultured for food in India.

It can be told apart from C. ornata by possessing fe…

D. polota is sometimes referred to as D. quadrifasciatus (Sevastianov, 1809) but the original name of the latter, Chaetodon quadrifasciatus Sevastianov, 1809, is a junior primary homonym of the older Chaetodon quadrifasciatus Bloch & Schneider 1801, thus Coius polota Hamilton, 1822 takes precedence.

This species is sometimes sold under the trade name of 'chameleon fish' due to its ability to rapidly change colour, especially when breeding or stressed. It was originally described as Labrus badis by Hamilton but Bleeker reclassified it as Badis buchanani in 1854; he had adopted the species name 'badis' as the new name for the genus and wished to avoid using a tautonym. At that time the use of tautonyms was avoided in zoological taxonomy but is now permissible under ICZN ru…