Canthophrys gongota

Canthophrys: from the Ancient Greek κανθός (kanthós), meaning 'corner of the eye' and οφρύς (ofrýs) meaning 'eyebrow', in reference to this' species peculiar orbital morphology.

gongota: presumably a local vernacular name for the fish.

Extensively distributed in the Ganges and Brahmaputra river systems in Nepal, northern India (states of Uttar Pradesh, West Bengal, Meghalaya, Assam, Manipur, and Arunachal Pradesh), and Bangladesh.

Type locality is 'rivers of northern Bengal'.

Mostly known from slow-moving, relatively shallow tributaries and minor rivers with substrates of mud, sand or gravel. Aquatic plants are only occasionally present but riparian vegetation apparently grows thickly at some localities.

In the Schutunga River, part of the Mansai River drinage which is itself a tributary of the Brahmaputra in West Bengal state, India, C. gongota has been collected alongside a number of other species including Schistura savona, Chaca chaca, Erethistoides sicula, Pseudolaguvia riberoi, P. shawi, and Macrognathus aral.

An aquarium with dimensions of 90 ∗ 30 cm36 ∗ 12 in or more is required.

Must be provided with a soft, sandy substrate since some of its time is spent completely buried, or with only eyes protruding. When coarser gravel is used it may become stressed or damage itself trying to dig, and feeding behaviour can be inhibited.

Other décor is not essential but could include water-worn rocks or driftwood branches or tree roots but be sure to add these prior to the substrate to prevent them being toppled by digging activity, and leave open patches of sand between for the fish to move around in.

Lighting can be quite dim unless you intend to grow plants, while a few handfuls of leaf litter would complement the natural effect.

Like many fishes that hail from running waters it is intolerant to accumulation of organic wastes and requires spotless water in order to thrive. For this reason it should never be introduced to biologically immature set-ups and adapts most easily to stable, mature aquaria.

In terms of maintenance weekly water changes of 30-50% tank volume should be considered routine. Provided oxygenation is adequate water movement is unimportant, and this species is also likely to do well in a stream-like arrangement if the substrate is fine enough for it to dig.

Chiefly a micropredator, sifting mouthfuls of substrate through the gills from which insect larvae, small crustaceans and suchlike are extracted.

In the aquarium it will accept sinking dried foods but should also be offered regular meals of small live and frozen fare such as Daphnia, Artemia, bloodworm, etc.

Not recommended for the general community aquarium, but can be maintained alongside fishes that inhabit the upper part of the water column such as small cyprinids. The presence of these should also help reduce timidity sincethe presence or absence of schooling fishes is often used as a marker for potential threats in nature.

Many sand-dwelling loaches from the families Cobitidae and Nemacheilidae are also suitable tankmates, but proper research is essential as some can be excessively aggressive or otherwise territorial.

It is a gregarious species so best kept in a group of six or more, and will exhibit some interesting behavioural interactions under these circumstances

Unlike the majority of cobitids male individuals lack a lamina circularis (structure formed by two or more fused rays) on the pectoral fins meaning young specimens can be difficult to sex accurately.

Older females grow noticeably larger than males and apparently develop a deeper body shape.

Unrecorded in captivity.

This species is often referred to as Somileptes gongota in aquarium literature, although that generic name has been considered a synonym of Canthophrys since 1998.

It is rarely seen in the aquarium trade, being notoriously delicate and difficult to ship.

The family Cobitidae, often referred to as 'true' loaches, is widely-distributed across most of Eurasia, with the Indian subcontinent, Southeast Asia and China representing particular centres of species diversity.

Phylogenetic analyses by Tang et al. (2006), Šlechtová et al. (2007) and Šlechtová et al. (2008) revealed that the group constitutes a separate genetic lineage to the family Botiidae. The two were previously grouped together under Cobitidae as the putative subfamilies Cobitinae and Botiinae.

All cobitids possess sharp, motile, sub-ocular (below the eye) spines which are normally concealed within a pouch of skin but erected when an individual is stressed, e.g., if removed from the water. Care is therefore necessary as these can become entangled in aquarium nets and, in larger species, break human skin.