Adenylate energy charge in three marine bivalve species during anoxia

Abstract

Abstract Influence of anoxia on adenylate energy charge (AEC) has been studied with three bivalve species from the Western Baltic Sea, Macoma calcarea, Cyprina islandica and Astarte borealis, which represent different levels of tolerance to anoxia, increasing in the order listed. Under normoxic conditions (10°C, 16.5%°S) the adenylate energy charge (a measure for the potentially available energy of an organism, ranging from 0 to a hypothetical maximum of 1.0) accounted to 0.80 for M. calcarea, 0.79 for C. islandica and 0.55 for A. borealis. A subsequent exposure to anoxia resulted in a decrease of AEC in all three species, with the lowest AEC measured in A. borealis, the species with the best tolerance to anoxia. To investigate the influence of temperature, experiments with M. calcarea and A. borealis were also conducted at 5 and 15 °C. It was found that an increase of temperature leads to increased AEC values in M. calcarea, but to decreased levels in A. borealis. The adaptive value of being able to lowe...