Pimelodus mysteriosus Azpelicueta, 1998

Ota, Renata Rúbia, Deprá, Gabriel de Carvalho, Graça, Weferson Júnio da & Pavanelli, Carla Simone, 2018, Peixes da planície de inundação do alto rio Paraná e áreas adjacentes: revised, annotated and updated, Neotropical Ichthyology 16 (2), pp. 1-111 : 84

Pimelodus mysteriosus Azpelicueta, 1998

Fig. 29

Body deep; greatest depth contained 3.3 to 4.1 times in SL; head length 3.1 to 3.9, anal-fin base length 6.4 to 8.8, adipose-fin base length 4.2 to 5.2, maxillary-barbel length 0.7 to 1.9 in SL; snout length 2.0 to 2.3, horizontal orbital diameter 3.2 to 5.8, least interorbital width 2.5 to 3.4 in HL; orbital diameter 0.9 to 1.2 in interorbital width. Mouth subterminal; dentigerous tooth plates in both premaxilla and dentary; teeth present in vomer and metapterygoid. Dorsal fin with I,6, pectoral fin with I,9, pelvic fin with 6 rays and anal fin with 16-19 rays. Ground color silvery to pale yellow; four dark-brown longitudinal series of blotches, usually equal to or larger than eye diameter. Dark-grey fins with black spots, especially on caudal and adipose fins.

Maximum standard length. 143.2 mm.

Biological data. Lives in the mainstream, rapids and near the shore; feeds on larvae, pieces of insects, gastropods, scales and eggs; the first gonadal maturation in females occurs with 120 mm SL and in males with 100 mm SL ( Azpelicueta, 1998).

Distribution. Paraná-Paraguay system.

Remarks. Some specimens of P. mysteriosus were identified as P. maculatus by Graça, Pavanelli (2007). Both species occur in the upper rio Paraná floodplain, but P. mysteriosus has been captured since 2003 by Nupélia staff. Deprá et al. (2015) widened the distribution of P. mysteriosus to the upper rio Paraná basin, previously known only from the río Paraguay and lower rio Paraná basins. Pimelodus mysteriosus is a nonnative species from the upper rio Paraná, and its occurrence can be associated with both the filling of the Itaipu Reservoir and the functioning of the Canal da Piracema (a fish ladder that connects the region downstream from the Itaipu Dam to the region upstream from the dam).

Figures

Fig. 29. a. Pimelodus maculatus, NUP 12783, 214.4 mm SL, lagoa da Onça, Batayporã, State of Mato Grosso do Sul. b. Pimelodus microstoma, NUP 18158, 117.6 mm SL, rio Azul, Palotina, State of Paraná. c. Pimelodus mysteriosus, NUP 10824, 158.0 mm SL, lagoa do Guaraná, tributary of the rio Baía, Taquarussu, State of Mato Grosso do Sul. d. Pimelodus ornatus, 208.0 mm SL, fresh specimen, uncat. e. Pimelodus paranaensis, 168.0 mm SL, uncat.