new species:
Australoheros kaaygua Casciotta, Almirón & Gómez, 2006
published in:
Casciotta, J.R., A.E. Almirón & S.E. Gómez (2006):
A new species of Australoheros (Teleostei: Perciformes: Cichlidae) from the río Iguazú basin, Argentina.
Zoologische Abhandlungen (Dresden) 55: 77-83
abstract (from publication):
Australoheros kaaygua sp. n. is described from the río Iguazú basin above Iguazú falls. Australoheros kaaygua sp. n. is distinguished from its congeners by the following combination of characters: 5–6 anal-fi n spines; 6–7 branched anal-fin rays; caudal-peduncle length 8.9–11.8 % of SL; lips not thickened; lateral band formed by two series of scales, each of them with a dark spot in its centrum. Between both scales there is a narrow light area; dorsal, anal, caudal fins and opercle without dark spots.
distribution (from publication):
Australoheros kaaygua sp. n. is known from streams flowing in the río Iguazú basin above the Iguazú falls.
remarks (from publication):
The following species of Australoheros from the Río de la Plata basin are considered valid: A. facetus (Jenyns, 1842), A. scitulus (Rican & Kullander, 2003), and A. tembe (Casciotta et al., 1995). Australoheros facetus is a widespread species inhabiting the basins of río Paraná, río Uruguay, and Río de la Plata. Australoheros scitulus is distributed in the río Uruguay and Río de la Plata basins. Australoheros tembe is known from streams flowing into the río Paraná and río Uruguay (Casciotta et al., 2003) in the Province of Misiones. The new species described herein comes from the río Iguazú basin above Iguazú falls and represents the first Australoheros species from that basin. Australoheros kaaygua differs from the other species of Australoheros in having a lateral band formed by two rows of scales leaving a narrow light line between them. In addition A. kaaygua differs from A. facetus in having 6–7 vs. 8–9 branched anal-fi n rays, longer head (35.2–38.4 vs. 34.2–35.4 % SL), shallower body (40.7–46.7 vs. 49.5–53.5 % SL), greater eye diameter (9.8–12.9 vs. 8.2–8.7 % SL), shallower and longer caudal peduncle (13.9–17.6 vs. 18.9–20.9 and 8.9–11.8 vs. 6.9–9.1 % SL respectively) and 6 vs. 8 gill rakers on first ceratobranchial. A. kaaygua is distinguished from A. scitulus in having 5–6 vs. 8–9 anal-fin spines, 12 vs. 13–14 pterygiophores in the anal fin, longer caudal peduncle (8.9–11.8 vs. 5.6–8.8 % SL), and the absence of dark spots on odd fins and opercle. Finally A. kaaygua differs from A. tembe in the absence of thickened lips.