| Adolfo's cory cat Corydoras adolfoi |  |
| African glass catfish, Three-striped glass catfish., Debauwi catfish Pareutropius debauwi | |
| Agassiz's dwarf cichlid Apistogramma agassizii |  |
| American flagfish Jordanella floridae |  |
| Angel Fish Pterophyllum scalare |  |
| Angel catfish Synodontis angelicus | |
| Arched cory, Skunk cory Corydoras arcuatus | |
| Armstrongs tetra, Brass tetra, Gold tetra Hemigrammus armstrongi |  |
| Arnolds red-eyed characin, Niger tetra, Red-eyed tetra Arnoldichthys spilopterus | |
| Aequidens curviceps | |
| Altolamprologus calvus |  |
| Ameca Splendens Butterfly goodeid |  |
| Ancistrus dolichopterus Dolly pleco, L183 | |
| Ancistrus temmincki Temmincks bristlenose, Bristlenose catfish | .jpg) |
| Anostomus anostomus Striped headstander | |
| Aphyosemion australe Cape Lopez lyretail, Lyretailed killifish |  |
| Aphyosemion striatum Striped killifish |  |
| Apistogramma agassizii Agassiz's dwarf cichlid | |
| Apistogramma hongsloi |  |
| Aplocheilus lineatus Golden wonder panchax | |
| Arnoldichthys spilopterus Arnolds red-eyed characin, Red-eyed tetra, Niger tetra | |
| Astronotus ocellatus Oscar, Velvet cichlid |  |
| Aulonocara jacobfreibergi Freiberg's Peacock Cichlid |  |
Too many fish? Overstocked tanks stress the fish in many ways: competition for food and space, bullying from other fish, deterioration of water quality and increased concentration of disease vectors. A lightly stocked tank will always be easier to care for, with more stable water quality