New Argentinian cichlid described

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A species of fish from a new South American cichlid genus has been described from the Rio Iguazu basin in Argentina.

The new fish, is a member of the recently erected Australoheros genus and has been named Australoheros kaaygua by Argentinian scientists Jorge Casciotta, Adriana Almiron and Serge Gomez in the latest issue of the journal Zoologische Abhandlungen Dresden.

Australoheros kaaygua was discovered in the Rio Iguazu basin above the Iguazu Falls in the north of Argentina, with most of the type specimens coming from the Misiones area and the comparative material from Buenos Aires and Corrientes.

Rican and Kullander's study of the new genus, which we reported recently, showed that the group contained three described species, A. facetus, A. tembe and 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". The authors do not state the previously used working name for A. kaaygua in the paper.

The new fish can be told apart from other members of the genus by the presence of 5-6 anal spines, 6-7 branched anal rays, its unthickened lips and a number of other features including a narrow light area between the scales, a lack of dark spots on the fins and opercula and by a lateral band of scales with dark spots in the centres.

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 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.

For more details on the new Australoheros species see the paper: Casciotta JR, Almiron AE and SE Gomez (2006) - A new species of Australoheros (Teleostei: Perciformes: Cichlidae) from the rio Iguazu basin, Argentina. Zoologische Abhandlungen Dresden. 55: 77-83.