Effects of temperature on athletic performance in the pelagic Mahi‐mahi (Coryphaena hippurus)

Abstract

Temperature is an environmental factor that can have profound impacts on physiological processes, behavior, and performance in poikilotherms. Temperatures that deviate too far from thermal tolerance are thought to reduce organismal performance by constraining aerobic scope. The objective of the present study was to examine how temperature influences metabolic rate, aerobic scope, and swimming performance in the circum‐global pelagic teleost Mahi‐mahi (Coryphaena hippurus). Mahi were acclimated to a range of temperatures experienced in their natural habitat (20, 24, 28, and 32°C) for 1–2 weeks and then aerobic performance was assessed using swim tunnel respirometry. Using this technique, maximal sustained swimming speed (Ucrit), maximal and minimal metabolic rate, and aerobic scope were measured. Mahi exposed to the lowest (20°C) and highest temperatures (32°C) experienced a reduction in aerobic scope compared to intermediate temperature treatments. A reduction in maximal metabolic rate accounted for the reduction in cold‐acclimated animals, while an increase in minimal metabolic rate led to the reduction in warm‐acclimated animals. Maximal sustained swimming speed showed similar but, non‐significant trends. These results indicate that performance is impaired in mahi at temperatures at the extreme ends of their natural range. These results are particularly relevant in the context of future climate change predictions for mahi residing in areas like the Gulf of Mexico, where 32°C is the mean temperature expected during summer months throughout surface waters by year 2100. Pairing data from the present study to environmental parameters may help assess habitat utilization by many pelagic species as oceans continue to warm.Support or Funding InformationThis research was made possible in part by a grant from The Gulf of Mexico Research Initiative. Data are/will be publicly available through the Gulf of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.orgThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.