Otocinclus flexilis – not a species from Argentina

Otocinclus affinis – not a species from Argentina

Ossancora punctata – first record from Argentina

Ossancora eigenmanni comb.nov. from Oxydoras

Oncorhynchus tshawytscha – a new exotic in Argentina

Oligosarcus itau sp.nov. from Salta, Argentina

Oligosarcus amome sp.nov. from Misiones, Argentina

Oligosarcus pintoi – first record from Argentina

Odontesthes humensis – first record from Argentina

Odontesthes argentinensis – first record from freshwaters