Responses of gill to various changes in salinity in fresh water teleost Colisa fasciatus (Bl. and Schn.)
Das, S.; Srivastava, G.J.
Zeitschrift für Mikroskopisch-Anatomische Forschung 92(4): 770-780
1978
ISSN/ISBN: 0044-3107 PMID: 749398 Document Number: 138556
The effects of different osmotic conditions were observed on the gills of a fresh water air breathing teleost C. fasciatus. In control fishes 2 types of specialized cells (mucous gland and mast cells) are found in the gill. There is no special type of chloride cell. None of the cells give AgNO3/HNO3 test. The size of the mucous cells varies from 5.50 .mu.m-5.94 .mu.m. After distilled water treatment, the epithelium is severely swollen and at some places completely desquamated from the lamellae, leaving only the blood capillaries and supporting pilasler cells, due to endosmosis. After 40% salt water treatment the exhaustive stages in mucous glands and marked shrinkage of the entire respiratory epithelium is observed. The excess of salt causes exosmosis, resulting in death of the fishes. After 8% salt water treatment the number and the size of mucous-producing cells of treated fish increases .apprx. 4 times as compared to control fishes during the 1st wk of adaptation. In case of 1 mo. treated fish the gill surface area increases extensively and is occupied by the mucous cells. These mucous producing cells are AgNO3/HNO3 positive indicating their transformation into chloride cells. The size of the mucous cell increases up to 19.63 .mu.m.