The barbels of the juvenile African catfish from eastern Nigeria: a micro morphological and functional study

Abstract

The micro-morphology of juvenile farmed African catfish, Clarias gariepinus barbel was investigated to enrich our knowledge of teleost biology as there is dearth information on this species barbel from available literature, and also for any functional morphological adaptation. After humane immobilization of the animal, the sample under study- barbels were dissected out and processed for routine histology. The histology revealed variation in the components of its root, stem and tip especially the relative size of the elastic cartilage core and surrounding connective tissue coat. The epithelium was of the stratified squamous cells containing mucous cells, taste buds, melanocytes and club cells. Beneath the epithelium was varying layers of highly vascularized and innervated connective tissue surrounding the linearly arranged elastic cartilage core. This micro-architecture can be related to an organ involved in both mechanoreceptor through extensive innervations and chemoreceptor by means of the taste bud gustatory apparatus. The elastic cartilage core will enhance flexibility during movement while the club cells will help in flight or fight. The histology from this study suggest that the barbel will aid guide the fish in movement especially avoiding obstacles and predators, help in food search and selection through gustation.