Thorny woodcat experts from Brazil and the USA have named a new genus of doradid catfishes in the most recent issue of the Proceedings of the Academy of Natural Sciences of Philadelphia.
José Birindelli and Mark Sabaj Pérez name the new genus Ossancora after the anchor-like shape of the base of the pectoral spine and its articulation with the pectoral girdle (Latin oss=bone and ancora=anchor).
Ossancora species have been regularly encountered in the aquarium trade, where they were known as "Doras" ("Doras" punctatus and "Doras" eigenmanni being the two most common species encountered). The authors recognise four valid species in the new genus, one of which (O. asterophysa) is described as new; the other three valid species are O. eigenmanni, O. fimbriata and O. punctata (pictured above).
Ossancora is distinguished from other thorny woodcats in having the unique combination of posterior coracoid process approximately as long as posterior cleithral process in adults, posterior cranial fontanel occluded, long maxillary barbel with smooth elongate branches, and teeth on the upper and lower jaws.
The four species are distinguished from each other by the branching on the maxillary and mandibular barbels, the morphologies of the swimbladder and bony plates in front of the dorsal fin, and the number of teeth on the upper and lower jaws.
Ossancora asterophysa is known from lowland areas in the Amazon River drainage in Bolivia, Brazil and Peru. The species name comes from the Greek aster, meaning star, and physa, meaning bladder, alluding to the proliferation of diverticula along the periphery of the swimbladder that is characteristic for this species.
Ossancora eigenmanni is known from the upper Paraguay River drainage and a single location in the upper Paraná River drainage (where it is believed to have been introduced).
Ossancora fimbriata is most commonly recorded from black and clearwater river channels and, unlike O. asterophysa, is apparently rare in whitewaters. It is known from the Amazon River drainage in Bolivia and Brazil.
Ossancora punctata has the widest distribution among the four species, where it is known from whitewater and blackwater habitats in lowland areas in the Amazon and Paraná-Paraguay River drainages in Argentina, Brazil, Bolívia, Colombia and Peru.
For more information, see the paper: Birindelli, JLO and MH Sabaj Pérez (2011) Ossancora, new genus of thorny catfish (Teleostei: Siluriformes: Doradidae) with description of one new species. Proceedings of the Academy of Natural Sciences of Philadelphia 161, pp. 117–152.
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