The driftwood catfish genus Tatia has been revised by Brazilian ichthyologists Luisa Sarmento-Soares and Ronaldo Martins-Pinheiro, who recognize twelve species and describe three of these as new.
The three new species described are T. caxiuanensis (named after the Floresta Nacional de Caxiuan, the area where this species was caught.), T. meesi (named after Dutch ichthyologist Gerloff Mees) and T. nigra (named after).
In addition to the three new species, the other nine species considerd valid in the study are: T. aulopygia, T. boemia, T. brunnea, T. dunni, T. galaxias, T. gyrina, T. intermedia, T. neivai and T. strigata.
Tatia caixuensisTatia caixuensis is distinguished from congeners in having a distinctive modified anal fin in males consisting of elongate rays without denticulations on the ray segments.
The new species is also distinguished by the following combination of characters: cranial fontanel wide and with a single opening, first infraorbital with pronounced ventral process, the nasal ossified as tubes without medial flanges of bone and not sutured to the mesethmoid, five branched pectoral-fin rays, deep snout of more than 46.7% head length, caudal-fin lobes of the same length in both adult females and males, 32 post-Weberian vertebrae, and an adult size of less than 50 mm standard length.
This species is known from the type locality in the Curu River, lower Amazon basin.
Tatia meesiTatia meesi is distinguished from congeners in having the dorsal surface of body, back and upper sides dark-brown sometimes with depigmented area around adipose fin and the cranial fontanel with two narrow openings: the anterior one between the mesethmoid and the frontal and the posterior one limited to the frontal.
It additionally differs in having a combination of the nasal ossified as a tube, with a narrow lateral flange not sutured to the mesethmoid, four branched pectoral-fin rays, caudal-fin lobes of the same length in both adult females and males, and an adult size of less than 50 mm standard length.
This species is known from the Essequibo River drainage in Guyana.
Tatia nigraTatia nigra is distinguished from congeners in having a dark brown body and a short postcleithral process of about 60.0% head length.
Additional features useful for distinguishing T. nigra include: postcleithral spine not reaching the vertical through the origin of the dorsal fin, the nasal with well developed medial flanges, and 32 post-Weberian vertebrae.
This species is known from the central Amazon, in the Uatum and Trombetas river drainages.
The revision is published in the most recent issue of the journal Neotropical Ichthyology.
For more information, see the paper: Sarmento-Soares, LM and RF Martins-Pinheiro (2008) A systematic revision of Tatia (Siluriformes: Auchenipteridae: Centromochlinae). Neotropical Ichthyology 6, pp.