| Odessa barb Barbus sp. Odessa |  |
| Oligancistrus sp. Polka Dot Oligancistrus sp. L020 |  |
| One-spot catfish Synodontis notatus |  |
| Ornate bichir Polypterus ornatipinnis |  |
| Ornate tetra, False rosy tetra, Bentos tetra, White-tipped tetra Hyphessobrycon bentosi |  |
| Oscar, Velvet cichlid Astronotus ocellatus |  |
| Oto, Midget suckermouth catfish, Dwarf sucker catfish Otocinclus affinis |  |
| Oligancistrus sp. L020 Oligancistrus sp. Polka Dot | |
| Oryzias latipes Rice fish | |
| Otocinclus affinis Oto, Dwarf sucker catfish, Midget suckermouth catfish | |
Cichlids? There are estimated to be over 2000 different Cichlid species in the wild, of all sizes, shapes and colours. Many require very specialist conditions such as those coming from the sandy/rocky waters of Lake Malawi and Lake Tanganyika. Others, such as the Apistogramma dwarf cichlids from the Amazon basin require softer water and a well-planted tank. In general cichlids do not make good community fish as they can get quite aggressive, especially when spawning - but a specialist cichlid tank is certainly a sight to behold, and can be very rewarding for the more experienced aquarist