A Study on some aspects of respiratory physiology: effect of salinity, starvation and photoperiod on seawater snail Planaxis sulcatus

Abstract

In Planaxis sulcatus, the results indicate A significant increase (P<0.05) in the rate of weight specific oxygen consumption was observed as a result of decreasing the salinity from 75 to 10 psu. A high rate of oxygen consumption was observed at salinities between 10 and 25 psu and any further increase in salinity caused a significant reduction in the rate of weight specific oxygen consumption.Starvation for the first days caused a sharp decrease in the weight specific oxygen consumption rate from 142.484 µl. gˉ¹. hrˉ¹ to 100.012 µl. gˉ¹. hrˉ¹. A further extension in the period of starvation to 20 days caused less pronounced decreased in the rate of specific oxygen consumption and beyond 2 days of starvation the snails became inactive.High rate of specific oxygen consumption was observed in the snails acclimated to 24 hr daily photoperiod (113.78 µl. gˉ¹. hrˉ¹) and the lowest was observed in the snails acclimated to zero daily photoperiod (53.55 µl. gˉ¹. hrˉ¹). in the snails acclimated to 12 hr daily photoperiod, the oxygen consumption rate was intermediated(86.81 µl. gˉ¹. hrˉ¹)