Nutan Ranjana Dasa & Braj Bhusan Prasad Singhb*
aUniversity Department of Zoology, Jai Prakash University, Chapra (Saran), Bihar, India
bDepartment of Zoology, Purvottar Railway College, Sonpur, Jai Prakash University, Chapra (Saran), Bihar, India
Received : 15th January, 2021 ; Revised : 14th February, 2021
Abstract– Gills are the prime respiratory organs in fishes which enable them to remove dissolved oxygen from water. The gills of fishes receive venous blood or de-oxygenated blood through afferent blood vessels and get oxygenated by the absorption of oxygen from water through thin and much vascularised epithelial layers of secondary lamellae of gill filaments. Thus gill is the centre for oxygenation. The gill filaments along with its primary and secondary lamellae provide greater surface area for the exchange of gases. The water with dissolved oxygen passes over the surface of gill filaments consisting of primary and secondary lamellae, oxygen is absorbed through thin wall and carbon dioxide is released into water. The absorbed oxygen comes into blood and then to the different cells for the purpose of intracellular oxidation and liberation of energy for the maintenance of life process. In addition to the gill or branchial respiration, most of the tropical fishes including Colisa fasciata show aerial respiration supplementing the gill respiration and involves accessory respiratory organs developed in response to the exceptional environmental conditions which include life in polluted water or life out of water for short period or while taking excursion on land and enable the fish to tolerate oxygen depletion in water during summer season.
Be First to Comment