Journal of the Marine Biological Association of India

Respiration in the clam Paphia laterisulca.

Volume 18 Issue 3

K. P. Dhamne and U. H. Mane

Abstract

The rate of oxygen uptake in Paphia laterisulca was reduced due to frequently opening and closing of the shell valves. The unit oxygen consumption was increased with decreasing body weight of the clams. With increase in temperature from 24 to 32°C, the rate of oxygen uptake increased progressively but decreased sharply from 38°C upto 40''C. The rate of oxygen uptake did not change between 30-26 %„ but above and below these salinities, the respiratory rate decreased. Below normal pH of 7.6 (acidic) the rate of oxygen uptake was increased but above that pH (alkaline) the rate was decreased. The starvation of the clams for six days resulted in 50 % reduction in the rate of oxygen uptake. Oxygen consumption increased during the period of exposure but after reimmersal into normal seawater the rate of oxygen uptake returned to original level. The oxygen uptake appeared to be directly related to the oxygen tension of the external medium, at very low tension of oxygen (1.5 ml/1) the rate of oxygen uptake retarded considerably. The clams showed distinct diurnal rhythmicity in the oxygen uptake: they consumed more oxygen in noon and less in midnight.

Date : 31-12-1976