Skeletal Deformities in Cultured Juvenile African Catfish Clarias gariepinus (Burchell, 1822)

Skeletal deformities in cultured fish are known worldwide and it had affected the survival, growth and appearance of the fish which contribute to production loss. Clarias gariepinus is known as number one farmed fish in Malaysia. C. gariepinus also effected in these deformities especially in cultured species. The objectives of this study are to identify the skeletal deformities that occur in juvenile stages and to compare the bone structure between the normal and deformed fish. A total of 50 juveniles’ fish were collected from Aquaculture Extension and Community Centre Machang, Kelantan. The juvenile was measured before undergo staining process. The fish were starved for one day then fixed in 70% ethanol for two weeks. The fish were then stained with alizarin red S for cartilage and Alcian blue for bone. The specimens were photographed in order to observe the deformities. The data showed only 13.0% juveniles have skeletal deformities, 10.9% with lordosis and 2.2% scoliosis. The cause of the deformities may be due to the heterogenous growth but other factors might also contribute to the problem. As the conclusion, the skeletal deformities observed in juvenile C. gariepinus were detected with the whole-mount staining method ranged from size 7.3 and 26.0 cm in total length. This study shows there is heterogenous growth rearing at low percentage even from skilled farm. Further study should concentrate on hidden factors that affected the deformity rate and mineralization of the juvenile fish.