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…

This species appears is rare in the aquarium hobby with the majority of images both online and in the published literature instead depicting H. confuzona or H. parclitella. All three are members of the H. ocellata ‘group’ within the genus which currently contains H. ocellata, H. bilineata, H. confuzona, H. orthogoniata, H. ogilviei and H. parclitella.

Following Tan and Ng (2005) these share possession of…

There are at least two variants available one of which is often traded as G.sp. ‘Araguaia orange head’. This is misleading since both are endemic to the Tapajós drainage (see ‘Distribution’), and appears to date back to an error in collection locality when the fish were first exported.

The two differ in the extent of orange colouration on the head which extends onto the opercle in G. sp. ‘orange head (rio Arapiuns form) but is mostly restricted to the area above the ey…

Known only from the rio Pindaré in Maranhão state, north-eastern Brazil which drains into the Baía de São Marcos (St. Mark’s Bay) along with the rios Mearim, of which it is sometimes considered a tributary, and Grajaú. Some sections of the Pindaré have been heavily degraded via removal of riparian vegetation for agriculture and habitats destroyed due to resultant siltation.

The river is poorly-studied and the conservation status of its fishes mostly unconfirmed so su…

This species is rare in the hobby though it’s name is often attached to shipments of other Geophagus species. It’s a member of the nominal G. surinamensis ‘group’ of closely-related species within the genus and can be identified by a combination of characters including: possession of dark preopercular marking; no vertical bars on the flanks; relatively large, roughly oblong-shaped dark midlateral marking; caudal fin brownish with 3-5 light stripes on upper lobe and less well-defined stripes or mottled pattern of light spots with narrow dark interspaces on lower lobe.

This species appears to be a relative ecological generalist. During a sampling trip in 1989 it was collected various habitat-types including a narrow (maximum width 3 m) stream containing shallow (maximum depth 1 m), transparent, moderate to fast-flowing water and substrate comprising gravel, mud, clay and organic debris including submerged logs. Aquatic plants consisted of water lilies and marginal vegetation was dense, comprising various trees, shrubs, grasses and ferns.

Juvenile specimens of this species are readily confused with those of other members of the 'G.' brasiliensis species group, but adults are easily-distinguished by their relatively smaller adult size and comparative lack of reflective blue scales on the body and head.

The genus Geophagus was rediagnosed by Kullander (1986) who restricted it to include only those species with paired caudal extensions to the swi…

Traded under various names including ‘mottled’, ‘eyepot’, ‘sand’ and ‘striped’ loach. It’s perhaps one of the better choices for those new to keeping nemacheilids being relatively hardy, peaceful and exhibiting some quirky behavioural traits. The characteristic ocellus, a dark marking at the top of the caudal peduncle that resembles an eye, is thought to have some function in predator distraction and is normally more intense in younger specimens.

This species was previously referred to as M. thoracata, but that name is now applied to the species with a relatively short dorsal-fin spine which was formerly known as M. personata.

M. picta can be told apart from M. thoracata by presence of a dark vertical bar in the caudal-fin, a comparatively longer dorsal-fin spine (52.0-64.0% vs. 32.0-48.0% of dorsal-fin base in specimens measur…

A good choice for the larger community tank. Newly imported fish tend to be a little delicate and can be susceptible to disease. This is at least in part because all specimens sold for the trade are wild caught. Once acclimatised it usually proves very hardy and adaptable….