How successfully can the methodology to study the metabolic rates of teleost be applied to Chondrichthyan fish?

JUAN MANUEL MOLINA; LICIA FINOTTO; TERENCE WALKER; RICHARD REINA

North Stradbroke

Congreso; 2018 Oceania Chondrichthyan Society conference; 2018

Oceania Chondrichthyan Society

The study of the physiology of Chondrichthyan fish has been a neglected area of research, particularly in comparison to teleosts of high commercial value. This is a cause of concern given that physiological variables are highly relevant for the assessment of the stability of fish population stocks and the sustainability of fisheries that depend on them. Among the diverse physiological variables available for study, the evaluation of metabolic rates offers valuable data for use in a diversity of applications. The determination of respiration rates has been widely used as a physiological method for assessing the metabolic rates of teleost fish. Here we present the advances of our study on the physiology of the commercially exploited Mustelus antarticus. We determined the routine metabolic rates (as these animals actively and constantly swim whilst in captivity) of 13 M. antarticus (size range 72-136.5 cm of total length). The aerobic scope of activity of this species was found to be very high (mean of 186 mg O2/kg of shark/hour), comparable to active pelagic species like Prionace glauca. The metabolic rate showed a negative relationship with length. The lowest rate estimated was for an adult female (70mg O2/kg of shark/hour) whilst the highest was for a young female(320mg O2/kg of shark/hour). These estimations represent the first for this species, and are preliminary, however we trust this information can readily be employed by the scientific community. Additional results will be obtained in the course of the current year, specifically, a measure of a maximum metabolic rate.