Our trial on the catfish in Aquaponics
A pair of weeks ago, we started our trial on the catfish in Aquaponics. We chose to rear two different species: the Walking catfish (Clarias batrachus) native to Southeast Asia and the African sharptooth catfish (Clarias gariepinus).
So, we stocked the two species into separate aquaponics tanks inside our first greenhouse. Obviously, the previous day we moved the koi carps into the aquaponics system inside our second greenhouse. While, we introduced the Fantail Goldfish from the second aquaponics system to the third one inside our first greenhouse.
We choose these species for their favourable characteristics. In fact, they’re easy to raise and in six months they get up to about 30 cm (0.9 ft) long. Furthermore, they’re omnivorous and it’s possible to integrate their feedstuff with veggie and fruit scraps. Most noteworthy, these are hardy species which tolerate high temperature. The latter is an important trait that we took into account when we choose them. Because of the vicissitudes we tackled with the previous fish species purchased due to their shipment conditions.
Nevertheless, the catfish is a delicacy that belongs to the culinary tradion of some Italian Regions. This is another reason why we chose this fish. Even if we prefered the African and the Southeast Asian catfish to the Italian one (Ameiurulus melas), which is disappearing from our lakes and rivers. But, the latter’s growth is slower. Indeed, it takes around 3 years to get the commercial size (60 cm/ 1,9 ft).
However, as precautionary measure of disinfection we treated them with non-iodized salt when they arrived. Its suitable concentration in Aquaponics is equal to 0.2% that amounts to 2 grams per liter. As a matter of fact, this is how much salt concentration the plants tolerate. (Nonetheless, it’s always necessary to make sure of the salt tolerance of the fish species treated as well!)