A new species of Moenkhausia tetra has been described from the Paraguay River drainage in a recent issue of the journal Neotropical Ichthyology.
Ricardo Benine, Tatiane Mariguela and Claudio Oliveira name the new species Moenkhausia forestii, and distinguish it from congeners in having a reticulate body and a conspicuous dark blotch on the caudal peduncle extending to the base of caudal-fin rays preceded by a lighter area, lateral line incomplete, 23"26 lateral-line scales, 5 scale rows above the lateral line, 4 scale rows below the lateral line, body depth 38.3"45.2% standard length, and an inconspicuous dark triangular humeral blotch located on second and third lateral line scales.
The new species is named after fish geneticist Fausto Foresti.
For more information, see the paper: Benine, RC, TC Mariguela and C Oliveira (2009) New species of Moenkhausia Eigenmann, 1903 (Characiformes: Characidae) with comments on the Moenkhausia oligolepis species complex. Neotropical Ichthyology 7, pp. 161"168.