African catfish is scientifically known as Clarias gariepinus (Burchell, 1822) as shown in figure 1.1, while the local name is Keli Afrika. It can develop huge with a greatest length at 170 cm (IGFA, 2001) and weight of 60 kg (Robbins et al., 1991). C. gariepinus have smoothed body without any scales. The shading fluctuates dorsally from dim to light chestnut and is frequently mottled with shades of olive and dark while the underside is a pale cream to white (Skelton, 2001).
From a biological perspective, C. gariepinus is verifiably the ideal aquaculture freshwater species in the world. It is widely distributed throughout Africa (Bruton et al., 1999). They are hardy and are able to thrive in harsh environmental conditions in muddy, turbid and oxygen depleted water bodies with the help of their accessory air-breathing organ (labyrinth organ) that allows them to breathe atmospheric oxygen (Hecht et al., 1988, Van der Waal, 1998).
C. gariepinus is one of the species among few and large freshwater species known as migratory fish species. C. gariepinus can be found in lakes and their affluent rivers and in wetlands. C. gariepinus occur mainly in quiet waters within lakes and ponds and prefer rather shallow and swampy areas with a soft muddy substrate and calmer water (Adewolu et al., 2008).
C. gariepinus are a critical
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High growth rates may also impose costs, including adverse effects on future development, growth, reproduction and swimming performance. Accelerated growth in response to previous food restriction provides evidence that growth rates are regulated. It suggests that fishes can ‘evaluate’ their achieved growth trajectory and adjust growth rates to buffer deviations from an ‘ideal’ trajectory (Broekhuizen et al., 1994). The expression of this growth regulation is dependent on several factors (Wilson and Osbourn, 1960; Ryan,