| Species | Name | Family | Habitat | Length (cm) | Trophic Level | Status |
|---|---|---|---|---|---|---|
| Ancistrus cirrhosus | Loricariidae | demersal | 9.1 SL | 2.0 | native | |
| Apteronotus brasiliensis | Apteronotidae | benthopelagic | 29.0 TL | 3.3 | native | |
| Argolebias adrianae | Rivulidae | pelagic | 5.1 SL | 3.2 | native | |
| Astyanax altiparanae | Acestrorhamphidae | benthopelagic | 16.4 TL | 2.9 | native | |
| Astyanax asuncionensis | Acestrorhamphidae | benthopelagic | 15.0 SL | 2.9 | native | |
| Astyanax eremus | Acestrorhamphidae | benthopelagic | 10.0 SL | 2.9 | native | |
| Astyanax jordanensis | Acestrorhamphidae | benthopelagic | 7.6 SL | 2.9 | native | |
| Astyanax lineatus | Lateral striped tetra | Acestrorhamphidae | benthopelagic | 12.0 SL | 2.9 | native |
| Astyanax totae | Acestrorhamphidae | benthopelagic | 8.2 SL | 2.9 | endemic | |
| Australoheros angiru | Cichlidae | benthopelagic | 7.7 SL | 3.2 | native | |
| Australoheros facetus | Chameleon cichlid | Cichlidae | benthopelagic | 19.3 SL | 3.3 | native |
| Australoheros kaaygua | Cichlidae | benthopelagic | 9.4 SL | 3.2 | native | |
| Brycon orbignyanus | Bryconidae | benthopelagic | 79.5 TL | 2.7 | native | |
| Bryconamericus ikaa | Stevardiidae | benthopelagic | 6.8 SL | 2.6 | endemic | |
| Bryconamericus pyahu | Stevardiidae | benthopelagic | 5.0 SL | 2.7 | native | |
| Cambeva davisi | Trichomycteridae | benthopelagic | 20.8 SL | 3.3 | native | |
| Characidium zebra | Crenuchidae | benthopelagic | 7.4 SL | 3.5 | native | |
| Cichlasoma dimerus | Cichlidae | benthopelagic | 11.7 SL | 3.0 | native | |
| Cnesterodon carnegiei | Carnegie's toothcarp | Poeciliidae | benthopelagic | 3.5 | 3.0 | native |
| Crenicichla iguassuensis | Cichlidae | benthopelagic | 33.0 SL | 3.3 | native | |
| Crenicichla lacustris | Cichlidae | benthopelagic | 35.2 TL | 3.3 | native | |
| Crenicichla niederleinii | Cichlidae | benthopelagic | 23.5 SL | 3.3 | questionable | |
| Crenicichla scottii | Cichlidae | benthopelagic | 24.0 SL | 3.3 | native | |
| Crenicichla tapii | Cichlidae | benthopelagic | 12.0 SL | 3.2 | native | |
| Crenicichla tesay | Cichlidae | benthopelagic | 11.5 SL | 3.2 | native | |
| Crenicichla tuca | Cichlidae | benthopelagic | 15.0 SL | 3.3 | native | |
| Crenicichla yaha | Cichlidae | benthopelagic | 14.6 SL | 3.3 | native | |
| Diapoma potamohadros | Stevardiidae | benthopelagic | 6.2 SL | 2.7 | native | |
| Epactionotus yasi | Loricariidae | benthopelagic | 2.2 | endemic | ||
| Garcialebias araucarianus | Rivulidae | benthopelagic | 3.5 SL | 3.1 | native | |
| Glandulocauda caerulea | Stevardiidae | benthopelagic | 4.4 SL | 3.2 | native | |
| Glanidium ribeiroi | Auchenipteridae | demersal | 22.0 SL | 3.5 | native | |
| Gymnogeophagus taroba | Cichlidae | benthopelagic | 9.1 SL | 3.3 | native | |
| Gymnotus carapo | Banded knifefish | Gymnotidae | benthopelagic | 76.0 TL | 3.6 | native |
| Hasemania maxillaris | Acestrorhamphidae | pelagic | 2.9 TL | 3.1 | native | |
| Hasemania melanura | Copper tetra | Acestrorhamphidae | pelagic | 4.4 TL | 3.2 | native |
| Heptapterus stewarti | Heptapteridae | demersal | 13.9 SL | 3.5 | native | |
| Hoplias guri | Erythrinidae | benthopelagic | 41.7 SL | 4.1 | native | |
| Hoplias malabaricus | Trahira | Erythrinidae | benthopelagic | 65.0 TL | 4.2 | native |
| Hoplisoma carlae | Carla's cory | Callichthyidae | demersal | 5.4 SL | 3.0 | native |
| Hoplisoma ehrhardti | Olive cory | Callichthyidae | demersal | 4.7 SL | 3.2 | native |
| Hyphessobrycon reticulatus | Acestrorhamphidae | benthopelagic | 5.3 SL | 2.9 | native | |
| Hyphessobrycon taurocephalus | Acestrorhamphidae | benthopelagic | 5.5 TL | 2.9 | native | |
| Hypostomus albopunctatus | Loricariidae | demersal | 40.0 SL | 2.0 | native | |
| Hypostomus derbyi | Loricariidae | demersal | 31.0 SL | 2.0 | native | |
| Hypostomus myersi | Loricariidae | demersal | 20.7 SL | 2.1 | native | |
| Hypostomus nigropunctatus | Loricariidae | demersal | 23.3 SL | 2.0 | native | |
| Iheringichthys labrosus | Pimelodidae | demersal | 43.5 TL | 2.9 | native | |
| Imparfinis hollandi | Heptapteridae | demersal | 23.0 SL | 3.2 | native | |
| Jenynsia diphyes | Iguaçu livebearer | Anablepidae | benthopelagic | 7.3 SL | 2.9 | native |
| Jenynsia eigenmanni | Creek livebearer | Anablepidae | benthopelagic | 2.9 | native | |
| Leporinus acutidens | Anostomidae | benthopelagic | 33.0 TL | 2.3 | native | |
| Leporinus striatus | Anostomidae | benthopelagic | 25.0 TL | 2.0 | native | |
| Megalancistrus parananus | Loricariidae | demersal | 58.8 SL | 2.0 | native | |
| Oligosarcus jenynsii | Acestrorhamphidae | benthopelagic | 31.0 TL | 4.0 | native | |
| Oligosarcus longirostris | Acestrorhamphidae | benthopelagic | 29.5 SL | 4.3 | native | |
| Oligosarcus oligolepis | Acestrorhamphidae | pelagic | 26.2 SL | 4.2 | native | |
| Otothyropsis biamnicus | Loricariidae | demersal | 4.0 SL | 2.2 | native | |
| Pachyurus bonariensis | La Plata croaker | Sciaenidae | benthopelagic | 25.0 SL | 3.5 | native |
| Pareiorhaphis parmula | Loricariidae | demersal | 2.0 | native | ||
| Phalloceros caudimaculatus | Dusky millions fish | Poeciliidae | pelagic | 6.0 TL | 3.0 | native |
| Phalloceros spiloura | Three point toothcarp | Poeciliidae | benthopelagic | 3.4 SL | 3.0 | native |
| Pimelodus britskii | Pimelodidae | demersal | 36.0 SL | 3.3 | native | |
| Pimelodus maculatus | Pimelodidae | benthopelagic | 51.0 TL | 2.9 | native | |
| Pimelodus ortmanni | Pimelodidae | benthopelagic | 29.5 SL | 3.3 | native | |
| Prochilodus lineatus | Streaked prochilod | Prochilodontidae | benthopelagic | 80.0 TL | 2.2 | native |
| Psalidodon bifasciatus | Acestrorhamphidae | benthopelagic | 12.9 SL | 3.0 | native | |
| Psalidodon dissimilis | Acestrorhamphidae | benthopelagic | 13.6 SL | 3.0 | native | |
| Psalidodon gymnodontus | Acestrorhamphidae | pelagic | 17.0 SL | 2.0 | endemic | |
| Psalidodon gymnogenys | Acestrorhamphidae | benthopelagic | 11.5 SL | 3.0 | endemic | |
| Psalidodon ita | Acestrorhamphidae | benthopelagic | 6.1 SL | 3.0 | endemic | |
| Psalidodon leonidas | Acestrorhamphidae | benthopelagic | 4.6 SL | 3.0 | native | |
| Psalidodon paranae | Acestrorhamphidae | benthopelagic | 16.4 TL | 3.0 | native | |
| Psalidodon varzeae | Acestrorhamphidae | benthopelagic | 8.3 SL | 3.0 | native | |
| Psectrogaster curviventris | Curimatidae | benthopelagic | 17.1 SL | 2.0 | native | |
| Pseudoplatystoma corruscans | Spotted sorubim | Pimelodidae | demersal | 182.0 TL | 4.5 | native |
| Rhamdia quelen | South American catfish | Heptapteridae | benthopelagic | 61.0 TL | 3.9 | native |
| Rhamdiopsis moreirai | Heptapteridae | demersal | 11.7 SL | 3.5 | native | |
| Rineloricaria langei | Loricariidae | demersal | 11.7 SL | 2.6 | native | |
| Rineloricaria maacki | Loricariidae | demersal | 13.6 SL | 2.5 | native | |
| Roeboides prognathus | Characidae | benthopelagic | 18.5 SL | 4.1 | native | |
| Salminus brasiliensis | Dorado | Bryconidae | benthopelagic | 100.0 SL | 3.8 | native |
| Salminus hilarii | Bryconidae | benthopelagic | 50.0 SL | 2.7 | native | |
| Schizodon isognathus | Anostomidae | benthopelagic | 35.0 SL | 2.4 | native | |
| Schizodon nasutus | Anostomidae | benthopelagic | 43.5 TL | 2.8 | native | |
| Steindachneridion scriptum | Pimelodidae | demersal | 100.0 TL | 4.3 | native | |
| Steindachnerina brevipinna | Curimatidae | benthopelagic | 22.6 TL | 2.0 | native | |
| Synbranchus marmoratus | Marbled swamp eel | Synbranchidae | demersal | 150.0 TL | 2.8 | native |
| Tatia jaracatia | Auchenipteridae | demersal | 6.6 SL | 3.3 | native | |
| Trichomycterus crassicaudatus | Trichomycteridae | demersal | 13.5 SL | 3.3 | native | |
| Trichomycterus igobi | Trichomycteridae | demersal | 9.0 SL | 3.2 | native | |
| Trichomycterus mboycy | Trichomycteridae | benthopelagic | 12.6 SL | 3.2 | native | |
| Trichomycterus naipi | Trichomycteridae | benthopelagic | 12.2 SL | 3.2 | native | |
| Trichomycterus papilliferus | Trichomycteridae | benthopelagic | 12.7 SL | 3.2 | native | |
| Trichomycterus plumbeus | Trichomycteridae | benthopelagic | 8.2 SL | 3.2 | native | |
| Trichomycterus stawiarski | Trichomycteridae | benthopelagic | 8.5 | 3.2 | native | |
| Trichomycterus taroba | Trichomycteridae | benthopelagic | 6.5 SL | 3.2 | native | |
| Zungaro zungaro | Gilded catfish | Pimelodidae | demersal | 140.0 SL | 4.5 | native |