This species is uncommon in the aquarium trade which is a little surprising given its huge natural range. Different populations can vary in colour pattern to an extent though all share the defining aspects given by Hamilton, comprising a diffuse yellow-golden marking on the operculum plus a dark spot on the caudal peduncle. The latter is usually surrounded by a variably-sized golden-yellow margin, and the dorsal-fin often contains irregular dark spots and streaks, these sometimes forming a longitudinal band.

In P. phutonio the flank markings comprise two black, vertically-orientated blotches, one posterior to the operculum and the other on the caudal peduncle, and within the P. conchonius group this patterning is shared with P. bandula, P. cumingii, P. didi, P. meingangbii, P. padamya, and P. tiantian.

It can be told apart from these by the following combination of characters: smaller adult size of 25 – 30 mm vs. at least 35 – 40 mm; minute maxillary barbels; incomplete lateral line with ab…

This fish is sometimes traded as Oreichthys cosuatis, O. sp. ‘high fin’, O. ‘umangii’ (a nomen nudum that has only ever been applied to an image of a fish in the book ‘Ornamental Aquarium Fish of India’; K. L.Tekriwal and A. A. Rao 1999), Puntius ‘arunavii’ or ‘neon highfin barb’.

It can be distinguished from congeners by the following combination of characters: absence of a dark marking in the anal-fin (vs. presence in other species); ½7½ scales scales between pelvic-fin origin and dorsal midline (vs. ½6½ in O. cosuatis and…

In the Barak River drainage, which flows through the north-east Indian states of Nagaland and Assam before bifurcating at the Bangladesh border, symaptric species include Barilius bakeri, B. barna, B. bendelisis, B. dogarsinghi, Laubuca laubuca, Esomus danricus, Devario aequipinnatus, D. annandalei, D. devario, Rasbora daniconius, R. rasbora,…

X. cancila is often seen referred to as ‘freshwater garfish’, and although it does superficially resemble the true gars of the family Lepisosteidae, it’s actually a member of the Belonidae, or needlefishes, the majority of which are marine or estuarine in existence.

There are currently just two species in the genus although the probable existence of a third member has been noted by Roberts (1989) among oth…

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 is also traded as ‘golden cobra snakehead’ and is available in the aquarium trade on a regular basis.

It can be distinguished from other Channa species by the following combination of characters: 51-54 lateral line scales; 45-47 dorsal-fin rays; 28-30 anal-fin rays; 8-12 cheek scales; 50-52 total verte…

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…

Following Grant (2007) this species is included in the B. dario complex of closely-related species within the genus alongside B. striata. They're characterised by body patterning consisting of a base yellow to golden colour with 7-9 blue, green, grey or black body bars usually with thinner, lighter bars between. In some individuals the…

Ecological studies have revealed this species to be more of a generalist than its chiefly insectivorous congeners.

Aquatic and terrestrial insects form a significant proportion of the diet, but substantial amounts of filamentous algae and diatoms are consumed with water mites, fish scales, isopods, nematodes and detritus also taken occasionally.

In the aquarium it’s largely unfu…