'Cichlasoma' scitulum Rican & KullanderDiagnosisDistinguished from both 'C.' facetum and 'C.' tembe by having 8-9 anal fin spines (vs. 6-7 (rarely 5 or 8), 5-7, respectively), 13-14 anal pterygiophores (vs. 12-13, 11-12, respectively), modally 17 dorsal fin spines (vs. 16), and modally 6 gill-rakers on first ceratobranchial (vs. 8, 7-8, respectively).
'Cichlasoma' scitulum, NRM 49314, paratype, adult, freshly preserved, from the type locality, Arroyo Rosario, Uruguay. Photo: S.O. Kullander.
'Cichlasoma' scitulum can be distinguished from ‘C.´ facetum also by having 14 caudal vertebrae (vs. 13), and from 'C.' tembe by a shorter caudal peduncle including only one or no vertebral centrum (vs. 3). The midlateral stripe is more prominent and the vertical bars are less intensive whereas in 'C.' facetum bars are much more prominent than the lateral band. 'Cichlasoma' scitulum is the only species in the group with black spots in dorsal, anal and caudal fin, and also dark spots on the opercle and anterior flank scales.
'Cichlasoma' scitulum, MCP 13944, paratype, adult, 80.2 mm SL, preserved, from Brazil, State of Rio Grande do Sul, Rio Uruguai basin, Arroio Quaraí-Mirim. Photo: S.O. Kullander.
Primary typeHolotype: NRM 36647, male, 88.5 mm SL. Uruguay, Departamento Colonia, Río de La Plata basin, Río Rosario drainage, Arroyo Colla, 500 m upstream from mouth into Río Rosario, upstream Paso Arballo (34°19´7"S 59°20´13"W). 17 November 1997. S.O. Kullander and F. Cantera.Etymologyscitulus Latin diminutive meaning handsome, pretty, etc., given in allusion to the relationship to 'C.' facetum (facetus means well-made, fine, elegant).Geographical distributionArgentina, Brazil and Uruguay, in the lower Uruguay River drainage and the Rosario River drainage in Uruguay.
Type locality of 'Cichlasoma' scitulum, Arroyo Rosario in Uruguay. Photo: S.O. Kullander.
Natural history Type locality of 'Cichlasoma' scitulum, Arroyo Rosario in Uruguay. Photo: S.O. Kullander.The type locality is a large stream, about 10 m wide at the collecting site. The species was found chiefly below a dam immediately below which expanded to a deeper pool, at most about 2 m deep. The water was mostly shallow, less than 1 m deep, and with a bottom of mixed rock, sand and gravel, providing for riffles. The water was slightly brownish, and slightly turbid. Some marginal vegetation extended into the water.Local nameNone recordedReferencesRican, O. & S. O. Kullander. 2003. 'Cichlasoma' scitulum: a new species of cichlid fish from the Río de La Plata Region in Argentina, Brazil, and Uruguay. Copeia, 2003: 794-802.
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