A new species of corydoradine catfish from the genus Aspidoras has been named by scientists.
Marcelo Britto, Flavio Lima and Alexandre Santos found the new species during an ichthyological survey of Chapada Diamantina, in Estado da Bahia, Brazil, and named the fish Aspidoras psammatides in a paper in the latest issue of the journal Neotropical Ichthyology.
The new Aspidoras has a striking colour pattern with an unusually low level of pigmentation, something which is unique among other members of the genus.
The catfish was discovered in the Rio Paraguacu in shallow sandy water and the authors believe its colouration is an adaptation to this environment:"Apparently these fishes share a lifestyle that involves dwelling in riverine sand bars, where they spend part of their time partially burrowed in the sand."Britto, Lima and Santos say that the colour pattern, elongated body and high position of the eyes on the head suggests to them that the fish shares much in common with the behaviour of sand-darting fishes such as Ammocrypta.
The new Aspidoras shares some similarities with Aspidoras velites, which was described by Britto, Lima and Moreira in 2002. Most unusually, the two fish have a gap between their dorsolateral body plates and their infraorbital bones are reduced.
These character states are believed to be paedomorphic - they're only usually seen in juvenile fishes. The fish also has a number of other apparently paedomorphic features making it quite an unusual species among the other known Aspidoras.
Fast-growing genusThe new species brings the total number of fish in the Aspidoras genus to 20, most of which occur shallow streams in Brazil.
Around 30% of these species have been described in the past eight years, virtually all from new ichthyological surveys of previously unstudied regions.
The authors say that the Chapada Diamantina area in which they found A. psammatides has also revealed a number of other fish species entirely new to science, including among other things a whole new assemblage of Copionodontine trichomycterid catfishes.
For more details on the new Aspidoras see the paper: Britto M, Lima F and Santos A (2005) - A new Aspidoras (Siluriformes: Callichthyidae) from rio Paraguacu basin, Chapada Diamantina, Bahia, Brazil. Neotropical Ichthyology, 3(4): 473-479.