Factorial Aerobic Scope Is Independent of Temperature and Primarily Modulated by Heart Rate in Exercising Murray Cod (Maccullochella peelii peelii)

Abstract

Several previous reports, often from studies utilising heavily instrumented animals, have indicated that for teleosts, the increase in cardiac output ( ) during exercise is mainly the resulṫ V b of an increase in cardiac stroke volume (V S ) rather than in heart rate (f H ). More recently, this contention has been questioned following studies on animals carrying less instrumentation, though the debate continues. In an attempt to shed more light on the situation, we examined the heart rates and oxygen consumption rates ( ; normalised to a mass of 1 kg, Mo 2 given as ) of six Murray cod (Maccullochella peelii peelii; Mo 2 kg kg) equipped with implanted mean mass ‫ע‬ SE p 1.81 ‫ע‬ 0.14 f H and body temperature data loggers. Data were determined during exposure to varying temperatures and swimming speeds to encompass the majority of the biological scope of this species. An increase in body temperature (T b ) from 14ЊC to 29ЊC resulted in linear increases in (26.67-41.78 mmol min Ϫ1Mo 2 kg kg Ϫ1 ) and f H (22.3-60.8 beats min Ϫ1) during routine exercise but a decrease in the oxygen pulse (the amount of oxygen *

Aerobic scope measurements of fishes in an era of climate change: respirometry, relevance and recommendations

“…Similar examples are widespread in the scientific literature (e.g. Cutts et al, 2002;Clark et al, 2005;Donelson et al, 2012), and the different outcomes have clear implications for data interpretation in an ecological context.…”

“…) and factorial aerobic scope (3.9) of the athletic pink salmon at 22°C [data for female fish ] with the same metrics of the sedentary Murray cod (Maccullochella peelii peelii) at the same temperature (2.0 mgmin −1 kg −1 and 3.8, respectively) (Clark et al, 2005). A comparison of the factorial aerobic scope of these species yields very little insight into their greatly contrasting lifestyles, while the absolute aerobic scope provides a good indication of their respective aerobic performances.…”

Moving with the beat: heart rate and visceral temperature of free-swimming and feeding bluefin tuna

“…; figures 2 and 5), which is impressive among fishes and vertebrates in general (Butler et al 1992(Butler et al , 2000Cooke et al 2003;Clark et al 2005bClark et al ,c, 2007Clark & Seymour 2006). Entertaining the suggestion that 130 beats min K1 is the maximum f H for T. maccoyii at 198C, and using a Q 10 of 2.3 (from Korsmeyer et al 1997a), the predicted maximum f H of T. maccoyii at 258C would be just above 200 beats min…”

Growth hormone transgenesis and polyploidy increase metabolic rate, alter the cardiorespiratory response and influence HSP expression to acute hypoxia in Atlantic salmon (Salmo salar) yolk-sac alevins

“…1). In the closed but intermittently flushed respirometry system, the rates of O 2 consumption (μmol min −1 ) were calculated, as previously described (Clark et al, 2005). Following a period where the chamber was sealed, it was then flushed with fresh water and the Ṁ O2 was determined from the time integral of the resulting P O2 curve (ʃP O2 ; kPa min ) multiplied by the oxygen capacitance (βw O2 ; μmol l −1 kPa −1 ), the flow of water (V; ml min −1 ) used to flush the chamber, and the reciprocal of the time (t; min) during which the compartment was sealed:…”