A study of the Chanchito cichlid genus has seen the erection of a new genus and the identification of three new fish species.
According to a new study by Rican and Kullander, which has recently appeared in The Authors journal, the Chanchito cichlids of the "Cichlasoma" facetum group are descendents of a single common ancestor and have been placed in a new heroine genus called Australoheros.
A further three new fishes have also been identified and placed in the new genus along with some other former "Cichlasoma" species in the facetum group. The genus contains A. tembe, A. scitulus, and at least seven undescribed species: A sp. "Forquilha", A. cf. facetus, A. sp. "Jacui", A. sp. "Jacutinga", A. sp. "Paraguay", A. sp. "Pirapo" and A. sp. "Uruguai".
Australoheros are characterised by a number of features, ranging from their unique breeding colouration which consists of an interruption in the abdominal bars in the middorsal area, the distinct xanthophore dots on the base of the tails of juveniles, and the lowest numbers of vertebrae and scale counts seen in the heroine group.
The new genus is found in the southern half of South America in the Rio Parana, Rio Paraguay and Rio Uruguay river systems and their tributaries, and the range spreads as far west as the foothills of the Andes and as far east as the coastal areas of Brazil, Uruguay and Argentina.
Australoheros tembe was described in 1995 by Casciotta et al, while A. scitulum was described as "Cichlasoma" scitulum by Rican and Kullander in 2003.
Although the name Cichlasoma has been in widespread use in the aquarium world for decades, the genus name was actually changed in 1983 to be restricted to a group of just 12 species found in South America.
Kullander, who moved restricted the genus in this way, recognised the need for a thorough study of all of the South and Central American cichlids and it was suggested that all other representatives of unknown genus be referred to as "Cichlasoma" in quotation marks until further work was done.
The Chanchito was the first neotropical cichlid to appear in the aquarium trade and is believed to date back to 1889 where it was kept in Europe by fishkeepers. However, the species has since disappeared from the hobby and very few of the new Australoheros genus have been seen for sale in the shops.
For more details see the paper: Rican and Kullander (2006) - Character and tree based delimitation of species in the