Vol. 8, Issue 6 (2019)

Author(s):
Soumya Hilal and Fouzia Hilal

Abstract:
Brain are the substrate for sensory perception, processing and behavioural output. Structural variation of the “command headquarter of the body” may be used to predict niches better than any other structure of an organism .The vertebrate brain is the main part of the central nervous system in vertebrates (and most other animals).The brain is at the front, in the head. It is protected by the skull and close to the main senses of vision, hearing, balance, taste, and smell. As an animal moves forward, its senses, collect data about the surroundings, and that data goes directly to the brain. Brains are extremely complex. The structure of all vertebrate brains is basically the same. There were notable differences in the rates of evolution of the different brain structures.The present study focuses on morphological variations in the brain of some teleosts: Anabas testudineus, Aplocheilus lineatus, Arius nenga, Carassius auratus and Clarius batrachus. Marked differences in the hind brain lobes of fishes were clearly reflected. The hind brain is equipped with well developed cerebellum, facial lobe, vagal lobe and somatic sensory lobes. Highly developed cerebellum is observed in Arius nenga. In Clarius batrachus, facial lobe is bilobed, in Arius nenga and Carassius auratus it is single lobed while it is absent in Anabas testudineus and Aplocheilus lineatus. Vagal lobe is bilobed in all the species studied except in Aplocheilus lineatus.Somatic sensory lobe is absent in Anabas testudineus and Aplocheilus lineatus,bilobed in Arius nenga and Carassius auratus while well developed in Clarius batrachus. Generally the brain showed a high degree of structural diversity in fishes taken for the study.