Metabolic suppression in the pelagic crab, Pleuroncodes planipes, in oxygen minimum zones.

The pelagic red crab, Pleuroncodes planipes, is abundant throughout the Eastern Tropical Pacific in both benthic and pelagic environments to depths of several hundred meters. The oxygen minimum zones in this region reaches oxygen levels as low as 0.1kPa at depths within the crabs vertical range.

Prolonged exposure to elevated CO(2) promotes growth of the algal symbiont Symbiodinium muscatinei in the intertidal sea anemone Anthopleura elegantissima.

Some photosynthetic organisms benefit from elevated levels of carbon dioxide, but studies on the effects of elevated PCO(2) on the algal symbionts of animals are very few. This study investigated the impact of hypercapnia on a photosynthetic symbiosis between the anemone Anthopleura elegantissima and its zooxanthella Symbiodinium muscatinei. Anemones were maintained in the laboratory for 1 week at 37 Pa PCO(2) and pH 8.

Intragel oxygen promotes hypoxia tolerance of scyphomedusae.

Populations of jellyfish are known to thrive in many low oxygen environments, however, the physiological mechanisms that permit these organisms to live in hypoxia remain unknown. The oxyregulatory abilities of four species of scyphomedusae were investigated, and it was found that Aurelia labiata, Phacellophora camtschatica, Cyanea capillata and Chrysaora quinquecirrha maintain steady oxygen consumption to below 20 hPa oxygen (<10% air saturation). Oxygen content of the mesoglea of A.