COMPARATIVE ANATOMY ON OLFACTORY STRUCTURES OF SNAKEHEAD FISHES: A CLADISTIC APPROACH AND DOCUMENTATION

Abstract

The olfactory apparatus in two different benthopelagic; snakehead fishes of Channa punctatus and Channa striatus (Channiformes: Channidae) were studied to explore the taxon based comparative morphometry among the experimental species. The olfactory apparatus of C. punctatus and C. striatus were separately fixed in aqueous Bouin’s solution and 4% paraformaldehyde in 0.1 (M) phosphate buffer (pH. 7.2); studied under optical light microscopes. The distinct anatomical variations [i.e., number of olfactory lamella in each rosette, diameter of olfactory chambers, shape and size of olfactory bulbs and lobes, length of olfactory nerve tracts, etc.] were examined. The histoarchitecture of olfactory rosette also shows prominent differences in arrangement pattern of olfactory lamellae, distribution of sensory and nonsensory cellular components, etc. These variations may reflect species specific differences belonging to genus Channa that helps in morphoanatomy based cladistic approach of fish taxonomy.