New catfish lives near hot spring


A new species of trichomycterid catfish able to live in very warm waters has been described from Bolivia.

The description of Trichomycterus therma new species, is published by Luis Fernndez and Guillermina Miranda in the latest issue of the Journal of Fish Biology.

Trichomycterus therma can be distinguished from all other members of the genus in having thickened transverse skin on the ventral surface of the head.

It further differs in having spatulate incisiform premaxillary teeth, large and rounded papilla-like structures the body, continuous segment of the laterosensory canal within the frontal with the presence of a segment between pores two and six, long laterosensory canal with four to six pores, maxilla with a short anterior process that is smaller than the main axis of the bone, and has an anterior orientation, mesethmoid shaft narrower than the width of the lateral cornua; prepelvic length 587"610% of standard length (SL), head width 191"228% SL; submaxillary barbel length 239"375% of head length (HL).

The new species is named after its ability to live in thermal water (from the Greek therma, meaning hot).

The type locality of the new species lies near the city of Potos in Bolivia.

According to the authors, it is ...a slightly sloping stream that arises from a spring and runs a short distance before emptying into the Ro Tarapaya (Pilcomayo-Paran basin) at an elevation of c. 3600 m a.s.l...

The clear water stream ranges between 1"15 m in width and 015"05 m in depth, and runs over clay and rock-pebble substrata with algae....At the spring source, the water emerges at 50 to 60 C into a small pool, which drains c. 400 m away from the source into the stream where water temperature cools down to 37 C.

The fishes occur mainly in the area where the water is 37 C and has a pH of 82...

At this stream, another species of trichomycterid catfish (T. tiraquae) able to tolerate high temperatures was also found.

The diet of T. therma consisted chiefly of benthic macro-invertebrates.

For more information, see the paper: Fernndez, L and G Miranda (2007)

A catfish of the genus Trichomycterus from a thermal stream in southern South America (Teleostei, Siluriformes, Trichomycteridae), with comments on relationships within the genus. Journal of Fish Biology 71, pp. 1303"1316.