Conservation news

A tiny new catfish for the Amazon Basin

  • The catfish measures just an inch long and is distinguished from related species by the conspicuous small dots that are distributed on its back and belly.
  • It was briefly described in print in 2006.
  • It has now been named and given a full taxonomic description in a paper in the journal Neotropical Ichthyology.

At a time when the mass destruction of the world’s biodiversity hotspots is often in the news, small glimpses of hope can come in the form of new discoveries. A new species of catfish — Parotocinclus variola — has recently been reported from the Amazon region. After its discovery, the catfish was briefly described in print in 2006, and has now been named and given a full taxonomic description in a paper in the journal Neotropical Ichthyology.

“The new catfish is a small species of about one inch long, that feeds on periphyton (algae and associated microinvetebrates), and lives [in] forest creeks,” Roberto Reis, a co-author of the new study, told Mongabay in an email. Reis is head of the Laboratory of Vertebrate Systematics at Pontifical Catholic University of Rio Grande do Sul in Brazil.

The genus Parotocinclus included 27 species prior to the new discovery. The paper notes a number physical differences between P. variola and other members of the genus Parotocinclus. One feature that distinguishes it from all other members of its genus is its unique pigmentation pattern, consisting of conspicuous dark dots smaller in diameter than a pupil that are distributed on its back and belly. The spots inspired its name, variola, for the variola virus, which causes smallpox.

Parotocinclus variola, a new species of catfish from the Amazon Basin in Colombia. The photograph shows the holotype — the specimen on which the scientific description of a species is based. This individual is a male. Photo by Pablo Lehmann.

P. variola is known only from a single location in the Quebrada Tacana — a small creek that is a tributary to the Amazon River in southern Colombia. There it favors the sandy creek bottom.

“It is not consumed by humans because of its tiny size, but it is certainly appreciated by the aquarium trade,” Reis said. He added that as far as he knows, P. variola is not being regularly exported for the aquarium business.

The conservation status of the new catfish remains uncertain since the species is so far known only from one location. But the researchers write that it is probably widely distributed in blackwater creeks and rivers in western Amazonia in Colombia, Peru, and Brazil. As significant threats to the species remain undetected, P. variola is likely to be categorized as a species of least concern by the International Union for Conservation of Nature, the researchers write in the paper.

Reis plans to take his taxonomic investigation of Parotocinclus variola further, he said, in order to “include it in broad phylogenetic frame of the loricariid catfishes, and uncover its evolutionary relationships to other species.”