A new species of parodontid tetra has been described from Guyana in a recent issue of the journal Zootaxa.
The new species, named Apareiodon agmatos by Donald Taphorn, Hernn Lpez-Fernndez and Calvin Bernard, is known from the upper Mazaruni River drainage in western Guyana.
The new species differs from all other members of the family in having an incomplete lateral line; it also has the most scales among parodontids.
Apareiodon agmatos is further distinguished from all other congeners (except for A. gransabana) in having a colour pattern of five dark stripes on the sides of the body.
This species is named after its incomplete lateral line (from the Greek word for fragment).
Contrary to most other species of Apareiodon and most Parodontidae, Apareiodon agmatos appears to inhabit backwaters or streams with little or no current.
Substrate was generally a mixture of sand and mud, frequently with abundant flocculent sediments and leaf litter.
Finer sediments were dominant in a quiet side embayment of the Mazaruni River where the fish were collected from large schools.
Radiographs revealed an extremely long intestinal tract, which along with the unusually high gill-raker counts and the habitat preferences, suggest a detritivorous diet.
This is in contrast with other taxa in the family which are generally thought to be periphyton scrapers.
For more information, see the paper: Taphorn, DC, H Lpez-Fernndez and CR Bernard (2008) Apareiodon agmatos, a new species from the upper Mazaruni river, Guyana (Teleostei: Characiformes: Parodontidae). Zootaxa 1925, pp. 31"38.