Comparing oxygen uptake rates of driftwood and wrack generalist talitrid amphipods

Rates of oxygen consumption in seawater standardized for size (mass or body length) were compared for a representative supralittoral, wrack generalist talitrid – Platorchestia platensis and a representative driftwood, specialist talitrid – Macarorchestia remyi. Oxygen consumption in seawater was significantly less in M. remyi. This confirms the view that a reduced standard metabolic rate, and consequent reduction in growth rate and final size achieved, was an important physiological mechanism involved in dwarfism and adaptation to driftwood in M. remyi. Reduced standard metabolic rate in driftwood specialist talitrids is contrary to the metabolic theory of ecology.