Many people choose catfish for Aquaponics. Catfish are very good at adapting to their environment, are not territorial and breed quite easily. They tolerate water temperature variations and come in a variety of breeds suitable for various locations. The warmer the water that you keep your catfish in, the quicker they will grow. If you are planning on eating the fish you are using in your Aquaponics system, Catfish are scale-less and have to be skinned, they mature fairly quickly and produce tasty white flesh.
Catfish require a high protein fish food, and it is also possible to rear your own worms to feed them. Raising Catfish in a barrel, an article originally published in the Organic Gardening and Farming in 1973 gives full details on how to do this.
You will probably purchase your catfish fingerlings (young fish) from your local pet shop or farm supplier. Place the bag of young fish inside your aquaponic tank this will allow the fish to adjust to the change in water temperature. Leave the bag for a few hours or overnight then open the bag and allow the fish to swim into the tank.
Eel tailed catfish are excellent fish for Aquaponics. They are bottom feeding omnivore, they can be fed sinking pellets and live food such as earthworms. The young fish are a mottled black and grey color. When mature these catfish can be brownish red, olive green or brownish purple in color. The tandanus have large spines that run along their pectoral and dorsal fins and their mouth is surrounded by four pairs of sensitive barbells.
Channel catfish are another popular Aquaponic fish, they too are omnivores and can be fed live food such as insect larvae or worms as well as high protein pellets. Channel catfish produce tender and good tasting meat. The color of a Channel catfish depends on the water it lives in, if it is clear (as it should be in an Aquaponics system) the catfish is very dark, almost black. If the water is murky the catfish can be yellow.
Although the brown bullhead catfish matures more slowly than some other Aquaponic fish, they are very hardy and will put up with a large variance in water temperature and water quality. As the name suggests the brown bullhead is an olive/brown color fading to cream on its belly. Another omnivore, bullheads can be fed insects, molluscs and pellets. The brown bullhead has a thick and rounded body sharp, sawtoothed, spines at the base of the dorsal and pectoral fins. Unlike most other catfish, the upper jaw of the brown bullhead juts out slightly farther than the lower lip.
Catfish are very suitable fish for Aquaponics, they are tolerant of a range of water temperatures, slow growing so will not outgrow your system and have pleasant tasting flesh.