A new species of Leporinus tetra has been described from the Amazon River in Brazil in a recent issue of the journal Zootaxa.
Geraldo dos Santos and Jansen Zuanon name the new species Leporinus amazonicus, and distinguishes it from all other congeners by the combination of a slender body (maximum body depth approximately 25% of standard length), 45"47 lateral-line sales and a colour pattern consisting of brownish-grey body with one small and elongated dark blotch on the flanks.
The new species is known only from the Amazon River (after which it is named) near Manaus, although it is expected to occur throughout most of the Solimes-Amazon floodplain.
The authors state that the new species is rare, but this may be due to the fact that they are not collecting in an area where it is most abundant.
For more information, see the paper: dos Santos, GM and J Zuanon (2008) Leporinus amazonicus, a new anostomid species from the Amazon lowlands, Brazil (Osteichthyes: Characiformes). Zootaxa 1815: 35"42.