Taphorn B., D.C., López-Fernández, H. & Bernard, C.R., 2008
Apareiodon agmatos, a new species from the upper Mazaruni river, Guyana (Teleostei: Characiformes: Parodontidae).Abstract
Apareiodon agmatos, new species, is described from the upper Mazaruni River and its tributaries, Essequibo Basin, in western Guyana. The new species is distinguishable from all other species of Parodontidae by having an incomplete lateral line. The scales of A. agmatos are more numerous than in any previously described parodontid. It has five incisorlike pedunculate teeth on the premaxilla aligned in a straight row, each with a large central spatulate cusp bordered on each side by a minute lateral cusp. The maxilla has two or infrequently three incisors. It shares an unusual pigmentation pattern of one dorsomedial and four lateral black stripes with A. gransabana, which was described from the neighboring upper Río Caroní drainage, Orinoco Basin. Apareiodon agmatos also shares with A. gransabana and Parodon guyanensis a higher number (5 versus 4) of teeth than other members of the genus in the premaxillary. Apareiodon agmatos and A. gransabana may also share an absence of thickening of the anterior pleural ribs noted by Starnes & Schindler (1993) for A. gransabana. While beyond the scope of this work, these features may prove sufficient to diagnose this group of species from the genus Apareiodon as currently recognized.
Taphorn B., D.C., López-Fernández, H. & Bernard, C.R.
Zootaxa, 1925: 31-38, 2008.