Ontogeny of respiratory function in crustaceans exhibiting either direct or indirect development

Abstract

AbstractDialysed haemolymph from the planktonic larvae of the Norwegian lobster Nephrops norvegicus possessed a lower O2 affinity than the benthic adult stage at equivalent pH. This difference could be correlated with the ability to maintain O2 uptake during progressive hypoxia; adult individuals showed better developed regulation than the larvae. The intrinsic O2 affinity of both larval and adult haemocyanin (Hc) could be modified by preexposure to chronic hypoxia. In contrast, there were no significant differences noted in either Hc O2 affinity or the ability to regulate O2 uptake during progressive hypoxia between newly hatched and adult individuals of the direct developing amphipod Echinogammarus pirloti. Unlike the case in N. norvegicus preexposure to chronic hypoxia did not result in any change in respiratory performance at the level of the whole animal or in intrinsic Hc O2 affinity. The changes (or absence of them) in these aspects of the respiratory biology of the two species examined are discussed in the context of their ecological requirements. © 1995 Wiley‐Liss, Inc.