Description and biology of African Catfish
In their natural state in Africa, this species occurs in lakes, streams, rivers, swamps and flood plains, many of which are subject to seasonal drying out. The most common habitats are swamps and floodplains where they can survive in the dry season thanks to additional air breathing organs. Clarias gariepinus migration takes the side of the larger bodies of water where the feed and mature at the age of about 12 months to temporarily flooded edge areas in order to reproduce. The final maturation of gonads is associated with an increased level of water.
Development and living conditions of the African catfish in nature
Under stable environmental conditions, adult Clarias gariepinus have mature gonads all year round. Ideally, a mature female can lay around 60,000 eggs / kg body weight. Before mating, males compete aggressively for females they mate with in single pairs, with the female wagging her tail vigorously to mix eggs and sperm and spread the fertilized eggs. Self-adhesive eggs stick to submerged vegetation and hatch within 20-60 hours, depending on the temperature. The yolk sac is absorbed within 3-4 days and the stomach is fully functional within 5-6 days after starting exogenous nutrition. Sexual differentiation begins between days 10 and 15 after hatching. The larvae feed and grow rapidly in warm (usually> 24 ° C) nutrient-rich floodplains, reaching 3-7 g in 30 days. When the flooded coastal areas dry up at the end of the rains, young and adult individuals return to deeper waters. In areas with two rainy seasons, there are usually two reproductive peaks during the year.
Worth to remember Clarias gariepinus
Initially, African catfish in their native environment were bred as a “police fish” to control over-breeding of tilapia in earthen ponds or as bait for fishing in Lake Victoria.
Intensive farming and consumption is associated with the use of extruded feed (for trout) and closed circuits with water recirculation.
In Europe, the main producers are the Netherlands, Belgium and Hungary.