Comparison of methods to quantify metabolic rate and its relationship with activity in larval lake sturgeon Acipenser fulvescens

Abstract

Until recently most studies have focussed on method development for metabolic rate assessment in adult and/or juvenile fish with less focus on measurement of oxygen consumption (ṀO 2 ) during early life history stages, including fast-growing larval fish and even less focus on nonteleostean species. In the present study we evaluated measurement techniques for standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope in an Acipenseriform, the lake sturgeon Acipenser fulvescens, throughout the first year of life. Standardized forced exercise protocols to assess MMR were conducted for 5 or 15 min before or after measurement of SMR.We used different levels of oxygen decline during the measurement period of MMR post forced exercise to understand the influence these may have on the calculation of MMR. Opercular rate and tail beat frequencies were recorded by video as measures of behaviours and compared to metabolic rate recorded over a 24 h period.Results indicate that calculated values for aerobic scope were lower in younger fish.Neither exercise sequence nor exercise duration influenced metabolic rate measurements in the younger fish, but exercise duration did affect measurement of MMR in older fish. Finally, there was no strong correlation between metabolic rate and the measured behaviours in the lake sturgeon at either age. Based on the results, we recommend that a minimum of 6 h of acclimation to the respirometry chamber should be given prior to measuring SMR, a chasing protocol to elicit MMR should ideally be performed at the end of experiment, a short chasing time should be avoided to minimize variation and assessment of MMR should balance measurement limitations of the probes along with when and for how long oxygen consumption is measured.

Assessment of family-derived metabolic traits for the conservation of an ancient fish

“…Whole-body oxygen consumption rates (MO 2 ) were measured using an intermittent flow respirometry system (Loligo Systems, Viborg, Denmark) to assess routine metabolic rate (RMR) at 25 DPF (yolk sac larvae), and standard and maximum metabolic rates (SMR and MMR, respectively) at 125 DPF. At each timepoint, eight fish per family treatment were used for respirometry trials following the protocols outlined by Yoon et al (2021) with some modifications. Measurement cycles consisted of the following parameters: 360 s flushing, 60 s waiting, and 300 s measurement.…”

Comparison of metabolic rate between two genetically distinct populations of lake sturgeon

“…Oxygen uptake rate ($$$ \dot{\mathrm{M}}{\mathrm{O}}_2 $$$, in mg O 2 h −1 ; a proxy for metabolic rate) was assessed using intermittent flow respirometry following the previously published protocol with modifications where applicable (Yoon et al, 2021). We used three sizes of metabolic chambers to accommodate age‐0 fish with a range of body mass throughout the studies (0.0157–11.09 g).…”

“…As the environment during early life could significantly influence phenotypic development in lake sturgeon (Dammerman et al, 2015 ), metabolic rate data in this analysis were used from age‐0 lake sturgeon that were raised under the same environmental conditions of temperature (16°C), dissolved oxygen (100%), and without substrate in rearing tanks. The data analyzed here include previously published and unpublished data (Bugg et al, 2020 , 2023 ; Yoon et al, 2020 , 2021 ; Yoon, Amjad, et al, 2022 ; Yoon, Bugg, et al, 2022 ; Yoon, Deslauriers, & Anderson, 2019 ; Yoon, Deslauriers, Enders, et al, 2019 ; Yoon, Groening, et al, 2022 ; Yoon, Laluk, et al, 2022 ).…”

“…As flowthrough aquaria were used to rear developing sturgeon, ammonia, nitrite, and nitrate levels were found to be negligible throughout the studies. Oxygen uptake rate ( ṀO 2 , in mg O 2 h −1 ; a proxy for metabolic rate) was assessed using intermittent flow respirometry following the previously published protocol with modifications where applicable (Yoon et al, 2021). We used three sizes of metabolic chambers to accommodate age-0 fish with a range of body mass throughout the studies (0.0157-11.09 g).…”

Integrated organismal responses induced by ecologically-relevantpCO2and temperature exposures in developing lake sturgeon

“…Metabolic rate was indirectly assessed by measuring whole-body oxygen consumption rate with intermittent flow respirometry (Loligo Systems, Viborg, Denmark). The protocol of measuring metabolic rate was performed as previously described 74 . It is worth to note that logistic constraints led to an invalid measurement of metabolic rate during the time of snow melt experiment due to the insurmountable measurement noise from low respiration and high bodymass:volume.…”