Whole-body endothermy in a mesopelagic fish, the opah, Lampris guttatus

  title={Whole-body endothermy in a mesopelagic fish, the opah, Lampris guttatus},
  author={Nicholas C. Wegner and Owyn E. Snodgrass and Heidi Dewar and John R. Hyde},
  pages={786 - 789}
A cold-water fish with a warm heart Mammals and birds warm their entire bodies above the ambient temperature. Generally, this ability is lacking in other vertebrates, although some highly active fish can temporarily warm their swim muscles. Wegner et al. show that the opah, a large deepwater fish, can generate heat with its swim muscles and use this heat to warm both its heart and brain. This ability increases its metabolic function in cold deep waters, which will help the fish compete with… 
Whole‐body endothermy: ancient, homologous and widespread among the ancestors of mammals, birds and crocodylians
There is strong evidence for whole‐body endothermy being ancient and widespread among amniotes and that the similarity of biochemical processes driving muscle NST in extant birds and mammals strengthens the case for its plesiomorphy.
The thermoregulatory system uses this mechanism also as a heat source during shivering, for example in the ascending phase of fever, and Sweating is less effective for heat dissipation in humid climate and the authors can observe a humid-heat acclimation.
Thermogenesis in ectothermic vertebrates
In vertebrates, endothermy is typically associated with birds and mammals while fishes, amphibians, and reptiles are generally typified as ectotherms, however, there are representatives in the latter group whose body temperature can be significantly influenced by thermogenesis.
Ontogeny of regional endothermy in Pacific bluefin tuna (Thunnus orientalis)
Red muscle endothermy was well developed, but visceral and cranialEndothermy were still developing, in the largest individuals studied.
Endothermy in the smalleye opah (Lampris incognitus): A potential role for the uncoupling protein sarcolipin.
Swimming strategies and energetics of endothermic white sharks during foraging
It is suggested that white sharks aggregating near seal colonies swim slowly and employ unpowered gliding in descents, presumably to reduce energetic cost of swimming while increasing encounter rates with fast-swimming seals.
The evolution of mechanisms involved in vertebrate endothermy
  • L. LegendreD. Davesne
  • Biology, Environmental Science
    Philosophical Transactions of the Royal Society B
  • 2020
It is shown that endothermy in mammals and birds is not as well defined as commonly assumed by evolutionary biologists and consists of a vast array of physiological strategies, many of which are currently unknown.
Comparison of Mitochondrial Reactive Oxygen Species Production of Ectothermic and Endothermic Fish Muscle
Endothermy and warming of Pacific Bluefin tuna red muscle may increase the potential for ROS production by muscle mitochondria but the evolution of endothermy in this species is not necessarily associated with a compensatory reduction of ROS production relative to the respiratory capacity of mitochondria.


The evolution of endothermy in mammals and birds: from physiology to fossils.
  • J. Ruben
  • Environmental Science, Biology
    Annual review of physiology
  • 1995
Endothermic warm­ bloodedness or, more correctly, endothermic homeothermy generally results from a combination of high resting, aerobically supported heat production rates in virtually all soft tissues, and insulation sufficient to retard excessive heat loss.
Mammal-like muscles power swimming in a cold-water shark
It is shown that the salmon shark, a lamnid inhabiting cold, north Pacific waters, has become so specialized for endothermy that its red, aerobic, locomotor muscles, which power continuous swimming, seem mammal-like, functioning only within a markedly elevated temperature range (20–30 °C).
Evidence for cranial endothermy in the opah (Lampris guttatus)
The hypothesis that the opah can maintain elevated cranial temperatures is supported and the proximal region of the paired lateral rectus extraocular muscle appears to be the primary source of heat.
Warm-Bodied Fish
Telemetry experiments show that the bluefin tuna can maintain a constant deep body temperature during marked changes in the temperature of its environment, suggesting the selective advantages of greater speed made possible by the warm muscle were important in the evolution of this system.
Evolution and Consequences of Endothermy in Fishes
Comparisons of tunas and their ectothermic sister species (mackerels and bonitos) provide no direct support of the hypothesis that endothermy results in increased aerobic swimming speeds, slow‐oxidative muscle power, or energetic efficiency.
The warm-bodied great white shark, Atlantic shortfin mako, and common thresher shark exhibit larger total gill surface areas than do ectothermic blue sharks, sandbar sharks, dusky sharks, or scalloped hammerhead sharks, but none of the three species exhibit spacing of secondary lamellae which differ significantly from the arrangements found in the ectotherms of elasmobranchs.
Review: Analysis of the evolutionary convergence for high performance swimming in lamnid sharks and tunas.
Encyclopedia of fish physiology : from genome to environment
This four volume encyclopedia covers the diversity of fish physiology in over 300 articles and provides entry level information for students and summary overviews for researchers alike.
Warm fish with cold hearts: thermal plasticity of excitation–contraction coupling in bluefin tuna
The results indicate that SR function is crucial to the performance of the bluefin tuna heart in the cold, and suggest that SR Ca2+ cycling is the malleable unit of cellular Ca 2+ flux, offering a mechanism for thermal plasticity in fish hearts.
Functional morphology of the gills of the shortfin mako, Isurus oxyrinchus, a lamnid shark
Despite specializations that increase mako gill area and efficacy relative to other sharks, the basic features of the elasmobranch gill design appear to have limited selection for a larger gill surface area, and this may ultimately constrain mako aerobic performance in comparison to tunas.