- Pirate perch
Aphredoderus sayanus
- Cape Lopez lyretail
Aphyosemion australe
- Agassiz's dwarf cichlid
Apistogramma agassizii
- Bullrout
Apistus carinatus
- Apteronotid eel
Apteronotus albifrons
- Japanese sandfish
Arctoscopus japonicus
- Atlantic argentine
Argentina silus
- Atlantic silver hatchetfish
Argyropelecus aculeatus
- New Granada sea catfish
Ariopsis bonillai
- Stripebelly puffer
Arothron hispidus
- Blind cave fish
Astyanax jordani
- Eendracht land silverside
Atherinomorus endrachtensis
- Gemfish
Atractosteus spatula