A new species of characin has been described from the waters of French Guiana and Suriname.
Zarsk, Gery and Isbrucker described the new characid species as Moenkhausia rara in the German journal Zoologische Abhandlungen.
The new species of tetra has brown lines, sometimes in a zigzag pattern, between the rows of scales and a round black spot on the caudal peduncle. There's also a faint humeral spot.
They also redescribe the poorly-known Peruvian species Moenkhausia simulata. This tetra has dark browny-black spots in the middle of each scale and lacks a caudal and humeral spot.
For the full meristic and morphological characters used to diagnose the species see the data given in the paper.
For more details see the paper (in German): Zarske, A, J Gry and I Isbrcker (2004) - Moenkhausia rara sp. n. - eine neue, bereits bestandsgefhrdete Salmler-Art (Teleostei: Characiformes: Characidae) aus Surinam und Franzsisch Guayana mit einer ergnzenden Beschreibung von M. simulata (Eigenmann in Pearson, 1924). Zoologische Abhandlungen 54: 19-30.