This section contains fish which grow very large, will not tolerate tankmates,
or require special attention to diet or water quality. They should only be kept by more
experienced aquarists and those who have the finances and time to cater for their long-term
needs.
| Species | Notes: reasons for classing as a 'difficult' fish |
Paddlefish
(Polyodon spathula) |
Can grow to more than 6ft (2 meters). Requires copious amounts of live daphnia. |
The impressive Red-Tailed Catfish
- suitable only for the largest of tanks
The huge Pacu - another tank-buster |
Irridescent shark/paroon shark
(Pangasius catfish) |
Grow very large. Can be prone to charging around the tank and bashing into the tank glass or other
obstacles and injuring themselves. Unsuitable for anything but very large aquaria. |
Red-tailed catfish
(Phractocephalus hemioliopterus) |
These fish can easily reach 3ft (one meter) in length, a recommended minimum tank
size is usually about 8 x 3 x 3ft. |
Pacu
(Colossoma macropomus) |
Another tank-buster, which can reach 4-5 feet (1.2-1.5m) in length! Even the slightly smaller
Red Pacu is only suitable for very large tanks. |
South American leaf fish
(Monocirrhus polyacanthus) |
A very demanding fish, which is difficult to acclimatise to aquarium conditions. They
require copious amounts of live food. |
