Despite being a wholly unsuitable aquarium subject, C. idella is often traded as such, with an albino form having been developed specifically for the ornamental market.

Individuals which have outgrown their aquarium or pond should never be released into natural waters, either, since this species has proven capable of causing serious environmental damage under a wide range of climatic conditions.

Occurs naturally in Brazil, Paraguay, Uruguay and Argentina with feral populations in Australia, New Zealand, Ethiopia and Malawi which were purportedly introduced for purposes of mosquito control but are now considered invasive.

Following Lucinda (2008) its natural range comprises the Lagoa dos Patos system, lower rio Uruguai, rio Tramandaí, and rio Mampituba in Rio Grande do Sul st…

An obligate piscivore capable of consuming surprisingly surprisingly large prey.

Newly-imported specimens may refuse to accept anything but live fishes although most can be weaned onto dead alternatives once they recognise them as edible, and some even learn to accept dried foods-

Like the vast majority of predatory fishes this specie…

This species is also known as the 'pearlscale' or 'mother-of-pearl' cichlid in deference to the iridescent body scaling. It's also worth noting that fishes sold as Gymnogeophagus australis in Europe are ‘G.‘ brasiliens is more often than not.

Wild specimens exhibits significant dissimilarities in body colour and patterning depending on locality with basic colouration being dominated by varying shades of blue, green or yellow, for example. Some populations al…

This species was formerly considered to be represented by the L-numbers L113 and L234 but it appears that only the former is native to the Paraná, Paraguay and Uruguay drainages, whereas L234 is collected in the rio São Francisco in eastern Brazil.

M. barrae and M. sp. ‘LDA097’ are also exported from the São Francisco system.

R. vulpinus is the most widely-distributed member of the family Cynodontidae.

Type locality is given simply as ‘Brazilian rivers’, but this species is currently understood to be distributed in the Amazon basin from the Río Ucayali system in Peru, eastward as far as the rio Xingu in Brazil, plus the rio Tocantins and Rio Capim basins.

It’s also known from the Río Orinoco ba…

Endemic to the Paraguay, Paraná and Uruguay river drainages in Brazil, Paraguay, Argentina and Uruguay.

The smallest of the three Aphyocharax species seen in the hobby, the redflank is relatively uncommon in the hobby in the aquarium trade.

It is also known as the Green Fire Tetra.

Widely-distributed throughout much of the Paraná and Uruguay river systems in Brazil, Paraguay, Argentina and Uruguay.

Some records from Buenos Aires province, Argentina are now considered to refer to the congener H. togoi (Miquelarena and López, 2006) so the common vernacular name ‘Buenos Aires tetra’ may not…

This species is also referred to as ‘velvet cichlid’, ‘red oscar’, ‘tiger oscar’, or ‘marble cichlid’.

It is a popular aquarium fish although its adult size and typical life-span of 10-20 years must be taken into account before purchase. Numerous ornamental strains are now available, and while care is more-or-less identical for all of them a degree of additional care must be taken with the ‘long-finned’ variety which is a little less competitive than other forms.

Numerous ornamental forms of this species have been selectively-bred for the aquarium trade. It has also been assigned the ‘A’ number A234 under the DATZ system with possibly conspecific, related forms similarly numbered A103, A104, and A105 depending on locality.