Aquafarming of catfish has become very popular in Africa, raising concerns about the nutritional benefits of this fish to consumers especially when compared to the wild catfish. Recent research conducted by University of Calabar, Cross Rivers State, Nigeria reveals that that aquacultured catfish contained significantly higher amounts of protein than the wild catfish, may be preferable for children, young adults and pregnant women who require a lot of protein for body. These differences in nutritional quality are related to the balance of nutritional value and composition of fish feeds.
Fish is a major source of animal protein and an essential food item in the diet of many Africans. It is suitable for complementing high carbohydrate diets typical of the low income majority group. Estimated global consumption of fish has continued to increase over the years, reaching 20, 5 kg/capital/year in 2018 from 9 kg/capita/year in 1961. It is expected to increase to 22 kg/capita/year in 2024. In some Asian countries particularly China, fish production from aquaculture exceeds that from captured fishes. A meta-analysis by Zhao ( 2016), showed that consumption of 60 g of fish daily is associated with a 12% reduction in mortality.
The benefits of fish are associated in part with high concentrations of bioavailable minerals, vitamins, essential fatty acids and protein. Fish consumption enhances proper mental development and improves immunity against diseases in growing children. Fish has no cultural or religious restrictions which makes it more advantageous than pork, beef and muttom.
- Clarias gariepinus or Catfish
Clarias gariepinus, also known as African sharptoothed catfish is a large, eel-like fish that is often dark gray or black in colour. It belongs to the kingdom: animalia, phylum: chordata, class: Actinopterygii, order: silunitormes, family: claviidae, genus: clarias and specie: gariepinus.
This fish specie has slender body, a flat bony head and broad terminal mouths with four pairs of barbells. C. gariepinus have large accessory breathing organs made of modified gill arches . C. gariepinus is an important part of many commercial and subsistence fisheries and is a major source of protein for people across Africa. It inhabits calm fresh water ranging from lakes, streams, rivers and swamps many of which are subject to seasonal drying. The fish has an almost Pan-African distribution, ranging from the Nile to West Africa and from North Africa to South Africa. The growth potential of catfish depends on environmental factors such as optimum temperature, water quality and nutrients.
Aquacultured fishes are grown in pens that are often submerged in ponds, lakes, and salt water. Wild fish on the other hand are caught in their natural environment. In Nigeria, the specie is of great interest to fish farmers because of their fast growth rates and efficient feed conversion, the use of pelleted floating feed has made a big difference to aquaculture development in Nigerian as C. gariepinus is being raised to maturity within 6 months. Artificial propagation of C. gariepinus is now carried out in hatcheries with hormonal induction. Despite the growing interest in aquacultured catfish production, not much has been documented on its nutritional capacity compared to that of the wild cat fish.
The aim of this study is to compare the nutrient composition of aquacultured and wild catfish obtained from Calabar metropolis, Cross Rivers State Nigeria, by comparing the proximate composition of aquacultured and wild catfish.
- Comparison of the nutritional quality
Results from this study reveal that aquacultured catfish contain significantly higher amounts of protein than the wild catfish. Also, this study revelated that the aquacultured catfish had more polyunsaturated fats; there was no significant difference in the vitamin content of the fishes.
The higher protein and polyunsaturated fats content observed in the aquacultured catfish relative to the wild catfish is attributed as a result of the composition of the artificially made feed which is usually fortified with appropriate nutrients to suit the growth and development of the fish. The composition of fish feed can affect the nutrients composition found in the body of catfish.
Which shows that the composition and nutritional quality of fish feed reflects the composition of fish and their nutritional quality.
Source : Okonkwo, C. et al. “Comparative Assessment of Nutrient Composition of Aquacultured and Wild Catfish (Clarias gariepinus) in Cross Rivers State Nigeria.”. Asian Journal of Fisheries and Aquatic Research, 8(2): 1-8, 2020.