Evolutionary and Integrative Approaches for Revealing Adaptive Mechanisms in Marine Animals along Environmental Gradients

The impact of climate change on temperate and polar marine regions have been under the spotlight for many decades, giving birth to a bloom of studies on the impact of temperature on ectotherms biology. As a result, different hypotheses emerged in an attempt to point out different mechanisms involved in the adaptation of aquatic ectotherms to environmental temperature with particular attention to temperature changes. Although this research has yielded major progress in our comprehension on how animals can respond to environmental changes, this information has been mainly obtained from ectotherms that inhabit polar, subpolar and temperate environments. Current evidence suggests that although the physiological mechanisms described could operate in the vast majority of organisms, the magnitude and temporality of the compensatory processes in the face of temperature changes could be different in tropical organisms. This is of major significance for tropical habitats since the only alternative to adapting to temperature increase is migration to colder environments, which might bring about extensive losses of biodiversity.

In this context, the aim of this Research Topic in Frontiers in Physiology is to integrate the knowledge generated from different species (crustaceans, molluscs and fish) in contrasting environments, mainly along the American Continent, with a particular concern for tropical species. We will consider different organization levels (from genes to organisms), in an attempt to formulate hypotheses that complement those that are currently established. Based on the climatic background, the regulatory mechanism involved in the tolerance of environmental stressors along the time of exposure will also be discussed. As susceptibility to environmental stressors might be linked to cellular ageing processes, we will investigate the lifespan of organisms for in the hopes of improving future experimental design. The cellular responses to environmental stressors will then be examined in different phases of the life cycle. We will explore how observed responses to environmental stressors can result from selective pressures, in an attempt to bring our ecophysiological studies into an evolutionary context. Finally, we wish to consider the paramount importance of bioenergetic adjustments in response to acute or chronic change in environmental conditions. Therefore, we will analyse the capacity to switch between aerobic and anaerobic pathways when optimal and sub-optimal conditions are fluctuating in animals. This will partly reveal resilience to a changing environment.

At the end of this Research Topic, different concepts, hypothesis, and methodological clues will be offered as a platform to expand the collaboration between research groups along the environmental gradients. This topic will search for hypotheses of more general application than those offered so far from the study of the species of cold or temperate water environments.