Aerobic and anaerobic movement energetics of hybrid and pure parental abalone

AbstractThe underlying mechanisms controlling growth heterosis in marine invertebrates remain poorly understood. We used pure blacklip (Haliotis rubra) and greenlip (Haliotis laevigata) abalone, as well as their hybrid, to test whether differences in movement and/or aerobicversus anaerobic energy use are linked to a purported increased growth rate in hybrids. Abalone were acclimated to control (16  °C) and typical summer temperatures (23 °C), each with oxygen treatments of 100% air saturation (O2sat) or 70% O2sat. The experiment then consisted of two phases. During the first phase (chronic exposure), movement and oxygen consumption rates ( ṀO2) of abalone were measured during a 2  day observation period at stable acclimation conditions. Additionaly, lactate dehydrogenase (LDH) and tauropine dehydrogenase (TDH) activities were measured. During phase two (acute exposure), O2sat was raised to 100% for abalone acclimated to 70% O2sat followed by an acute decrease in oxygen to anoxia for all acclimation groups during which movement and ṀO2 were determined again. During the chronic exposure, hybrids andH. laevigata moved shorter distances thanH. rubra. Resting ṀO2, LDH and TDH activities, however, were similar between abalone types but were increased at 23  °C compared to 16 °C. During the acute exposure, the initial increase to 100% O2sat for individuals acclimated to 70% O2sat resulted in increased movement compared to individuals acclimated to 100% O2sat for hybri...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - Category: Physiology Source Type: research