A new species of thorny catfish in the genus Leptodoras has been described from the Tapajs and Xingu river drainages.
The new species is named Leptodoras oyakawai, after Brazilian ichthyologist Osvaldo Oyakawa by Jos Birindelli, Leandro Sousa and Mark Sabaj Perz in the latest issue of the journal Neotropical Icththyology.
Leptodoras oyakawai can be distinguished from congeners in having a moderately-sized gas bladder with simple walls (diverticula absent), and paired bony capsules on anteriormost vertebrae reduced to paired cup-like laminar ossifications separated by a triangular septum.
Some individuals of the new species were collected ...at night on a large sandy shoal where the main channel was wide and shallow (depth less than 2 m) and current sluggish, while others were collected at night along a sandy beach aside the main channel in moderate current.
For more information, see the paper: Birindelli, JLO, LM Sousa and M Sabaj Perz (2008) New species of thorny catfish, genus Leptodoras Boulenger (Siluriformes: Doradidae), from Tapajs and Xingu basins, Brazil. Neotropical Ichthyology 6, pp. 465"480.