Physiological Responses in Aquatic Organisms Adapted to Extreme or Changing Environments

Extreme environments may be considered as those showing remarkable conditions, edging the limits of physical-chemical environments or imposing great variations along the life cycle of inhabitant organisms. Some examples were described in deserts, deep oceans, alkaline (around pH 10) or acidic waters (pH close to 5), salinities higher than those found in seawater, ion-poor waters, and polar regions with subzero temperatures. Although organisms, namely vertebrates and invertebrates, may be highly adapted to live in such environments, they are vulnerable to further unpredictable perturbations that can affect the morphology, physiology, and behavior. Some critic perturbations include ocean acidification, increased temperature or alterations in water parameters, leading to important physiological, biochemical and molecular readjustments. Thus, these environmental conditions can modulate the acclimation capacity of aquatic organisms.

In the last years climate change has been of major concern, and studies related to this issue are gaining momentum. Some predictions have been reported by these studies, like direct effects on metabolic and developmental rates; alterations of species distribution; decoupling of phenological relationships between species; and plasticity adaptation, where some species could undergo microevolutionary changes.

Therefore, the aim of this Research Topic is to provide up-to-date information on the physiological responses in aquatic organisms, vertebrates and invertebrates, adapted to extreme or changing environments as well as their interactions with endocrine, biochemical and molecular mechanisms. Studies with an approach related to conservation biology also are invited to contribute, because in many situations they report important information about adaptive capacity and resilience of species.

This Research Topic is specifically interested in original research and review articles.