A new species of Serrasalmus (Teleostei: Characidae: Serrasalminae), S. altispinis, is described from Uatumã basin (Amazonas, Brazil), with a complementary description of S. rhombeus (Linnaeus, 1766) from the Guiana shield

Abstract

Serrasalmus rhombeus (Linnaeus, 1766), described from Surinam, is recorded from the Amazon, the Orinoco and the Guiana coastal basins. Cited from the Maroni to the Iracoubo basins in French Guiana, S. rhombeus is recorded from the Araguari basin (Amapâ, Brazil). In the Uatumã basin (Amazonas, Brazil), S. rhombeus is sympatric with a new species, Serrasalmus altispinis. The body of S. altispinis is lightly more compressed and deeper than in S. rhombeus. S. altispinis is mainly characterized by the presence of 4 supraneurals (vs. 5 in S. rhombeus) and deeper serrae. These characteristics are shared with S. altuvei, S. compressas and S. geryi, three species of piranhas with a deep and compressed body, but different from S. altispinis.