This species is uncommon in the aquarium hobby. It is similar to the congeners C. borneensis and C. lorteti but can be told apart by males possessing a red (vs. bluish to greyish with black and white distal bands in C. lorteti) caudal-fin and lacking (vs. possessing) a black blotch at the base of the dorsal-fin.

This species is also referred to as ‘South American puffer’, ‘SAP’, ‘Amazonian puffer’, ‘Peruvian puffer’, or ‘Brazilian puffer’ in the ornamental trade.

Within the genus Colomesus, C. asellus can be immediately identified by possessing a unique transverse row of dermal flaps across the chin which is absent in its congeners C. psittacus and C. tocantinensis.

Known from the lower Mekong basin in Thailand, Vietnam, and Cambodia, the Chao Phraya watershed in central Thailand, and may occur in smaller river systems between.

Type locality is ‘Thu-dâu-môt, Vietnam’.

This species is distinguished from its Australian congeners S. jardinii and S. leichardti by possessing a lower number of lateral line scales (21-26 vs 32-36).

It occurs naturally in a number of colour forms of which three were elevated to distinct species status in 2003, but the current majority view is that all represent S. formosus pending a detailed review. Kottelat (2013) mentions that the red form may…

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.

There also exists a sister-group relationship between the Melanotaeniidae and Malagasy family Bedotiidae, which may seem surprising given their respective modern-day distributional patterns. The precise origin and subsequent dispersal of the two families has been the subject of debate, with some palentologists suggesting that Madagascar’s freshwater fishes derived froma trans-oceanic dispersal during the Cenozoic Era, but the most compelling arguments currently indicate a freshwater radiation which occurred during the Mezozoic break-up of Gondwana.

This species is relatively common in the aquarium hobby but contrary to popular belief is not venomous in any way. Its dorsal and opercular spines can pierce the skin, however, meaning extreme caution is necessary when netting it or performing aquarium maintenance.

The genus Allenbatrachus was erected in 1997 to accom…

Described from the Maros River (Salo Maros), southwestern Sulawesi, Indonesia and subsequently recorded from rivers and streams throughout the southwestern arm of the island including Lake Tempe (Danau Tempe), plus the Mota Talau River, East Timor state on the nearby island of Timor.

More recently Herder and Chapuis (2010) reported it to be more widespread on Sulawesi, with new records pertaining to an unnamed small stre…

This is one of the largest freshwater fish species in the world, and clearly shouldn’t be considered a home aquarium subject at all given its eventual size and the fact it can live for well in excess of 50 years. We include it here only because some public aquaria are able to maintain it long-term.

Unfortunately, juveniles are seen for sale quite regularly in the aquari…