Identification of different physiological functions within the gills and epipodites of the American lobster: Differences in metabolism, transbranchial transport, and mRNA expression.

Transbranchial transport processes are responsible for the homeostatic regulation of most essential physiological functions in aquatic crustaceans. Due to their widespread use as laboratory models, brachyuran crabs are commonly used to predict how other decapod crustaceans respond to environmental stressors including ocean acidification and warming waters. Non-brachyuran species such as the economically-valuable American lobster, Homarus americanus, possess trichobranchiate gills and epipodites that are known to be anatomically distinct from the phyllobranchiate gills of brachyurans; however, studies have yet to define their potential physiological differences.

Impact of heatwaves and environmental ammonia on energy metabolism, nitrogen excretion, and mRNA expression of related genes in the indicator model system Daphnia magna.

Due to increasing anthropogenic impacts, heatwaves and prolonged exposure to elevated concentrations of ammonia (HEA) may occur in aquatic environments as a single stressor or a combination thereof, potentially impacting the physiology of exposed animals. In the current study, common water fleas Daphnia magna were exposed for one week to either a 5°C increase in temperature, an increase of 300 µmol l total environmental ammonia, or to both of these stressors simultaneously. Exposure to elevated temperature caused a decrease in MO, ammonia excretion rates, a downregulation of mRNA coding for key Krebs cycle enzymes and the energy consuming Na/K-ATPase and V-type H-ATPase, as well as the energy distributing crustacean hyperglycemic hormone Rh-protein.

Impact of climate change on the American lobster (Homarus americanus): Physiological responses to combined exposure of elevated temperature and pCO.

The physiological consequences of exposing marine organisms to predicted future ocean scenarios, i.e. simultaneous increase in temperature and pCO, have only recently begun to be investigated.