Comparative Morphometry and Histological Studies of the Cerebellum of Catfish (Clarias gariepinus) and Tilapia (Oreochromis niloticus)

Introduction: The cerebellum is the major organ responsible for balance and equilibrium of the body and also coordinates the muscular tone. There is dearth of information on the comparative morphometric and histological organization of the cerebellum of both Catfish (Clarias gariepinus) and Tilapia (Oreochromis niloticus).

Aims: This study is aimed at studying the gross, morphometry and neurohistologic organization of the cerebellum of Catfish and Tilapia.

Materials and Methods: A total of twenty (20) apparently healthy adult fish were Used. The fish were bred and raised in captivity with known medical records, identified and characterized at the fisheries department of Usmanu Danfodiyo University, Sokoto. Both the Catfish (Oreochromis niloticus) and Tilapia (Clarias gariepinus) were dissected to remove the brain.

Results: Gross, morphometry and histological differences of the cerebellum of the two species were studied. Catfish (Clarias gariepinus) brain was observed to be an elongated organ with distinct section situated just under roof of the skull. The anterior end of the cerebellum was closely associated with the caudal poles of the cerebral hemisphere, while the posterior end closely association with the pons and medulla. Catfish (Clarias gariepinus) brain was observed to be elongated organ with distinct section situated just under the skull roof. In Oreochromis niloticus the anterior end of the cerebellum was closely associated with the caudal poles of the cerebral hemisphere, while the posterior end being in close association with the pons and medulla. The cerebellum was covered by a transparent layer which invaginated into the fissures between the folia and also showed gyri and sulci. The cerebellum was observed to be connected with the midbrain rostrally and the medullar oblongata caudally via the peduncles. The cerebellum of both the species presented common anatomical features but exhibited some variations so far their gross and histological morphology.

Conclusion: This study shows the morphometric and histomorphological differences in the cerebellum of Catfish (Clarias gariepinus) and Tilapia (Oreochromis niloticus) which could have contribute to the variation in their swimming pattern.