Warm brain and eye temperatures in sharks

@article{Block2004WarmBA,
  title={Warm brain and eye temperatures in sharks},
  author={Barbara A. Block and Francis G. Carey},
  journal={Journal of Comparative Physiology B},
  year={2004},
  volume={156},
  pages={229-236}
}
Summary1.Temperatures in the brain and eyes of mako and porbeagle sharks (Lamnidae) are 5°C warmer than the water while the brain and eye temperatures in six other species of pelagic sharks are within 0.1°C of water temperature.2.An orbital rete mirabile is present in the porbeagle and mako sharks but absent in the cranial vasculature of eleven other species of pelagic sharks.3.The orbital rete in the head of the porbeagle and mako sharks acts as a heat exchanger which conserves metabolic heat… 
Swimming muscle helps warm the brain of lamnid sharks
TLDR
Experiments with heat generation by model brains indicate that the metabolic heat produced by the brain is probably not sufficient to cause the temperature elevations observed, so metabolic heat imported from the red swimming muscle may be a valuable addition to the heat budget of the head.
Warm Eyes Provide Superior Vision in Swordfishes
TLDR
It is shown that warming the retina significantly improves temporal resolution, and hence the detection of rapid motion, in fast-swimming predatory fishes such as the swordfish.
Evidence for cranial endothermy in the opah (Lampris guttatus)
TLDR
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.
Cranial endothermy and a putative brain heater in the most basal tuna species, Allothunnus fallai
TLDR
Findings suggest that A. fallai has evolved extraocular muscles that may function to warm the brain and eye region and that this mechanism for cranial endothermy among the tunas is a heat exchanger.
The effect of ocular heating on vision in swordfishes.
CONTENTS U.S. Pacific Island Fishery Managers Address Overfishing of Bigeye Tuna 4 Publications of Note 4 Fishing Regulations Recommended For Proposed NWHI Sanctuary 5 Upcoming Events 5 retina
Through a lens sharply
TLDR
The blue fin tuna ( Thunnus thynnus) is a wide ranging pelagic predator and vastly overexploited food resource with enviable visual mechanisms, but the animal is extraordinary in several other aspects as well.
Thermal and Bioenergetics of Elasmobranchs: Bridging the Gap
Physiological telemetry is a powerful tool in studying the thermal biology and energetics of elasmobranchs in the laboratory and field. Controlled laboratory studies have increased our understanding
Evolution and Consequences of Endothermy in Fishes
TLDR
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 red muscle morphology of the thresher sharks (family Alopiidae)
TLDR
The present study investigated the comparative RM morphology of the other two thresher shark species, bigeyeThresher, Alopias superciliosus, and the pelagic threshers, for which there is no information regarding their capacity for RM endothermy, and compared these data with published works on A. vulpinus.
Relative Eye Size in Elasmobranchs
TLDR
A significant positive correlation was found between absolute eye size and relative eye size, but some very large sharks, such as Carcharodon carcharias have absolutely large eyes, but have relatively small eyes in relation to body mass.
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 31 REFERENCES
Regulation of brain and eye temperatures by the bluefin tuna.
TLDR
A counter-current heat-exchange system in the blood supply to the brain and eye allows metabolic heat to accumulate in these organs and raise their temperatures.
The Visceral Temperatures of Mackerel Sharks (Lamnidae)
TLDR
Measurements of temperature by acoustic telemetry from freeswimming sharks over a 4.5-day period do not give a convincing indication that stomach temperature is altered in a manner independent of the environment.
A brain heater in the swordfish.
TLDR
The brain and eye of swordfish are warmer than the water, and a tissue that heats the brain is associated with one of the eye muscles that protects the central nervous system from rapid cooling during daily vertical excursions.
Warm-Bodied Fish
TLDR
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.
Brain cooling in endotherms in heat and exercise.
  • M. A. Baker
  • Chemistry, Medicine
    Annual review of physiology
  • 1982
TLDR
The process has been studied most intensively in panting carnivores and artiodactyls in which the structure of the nasal cavity and the arrangement of the blood vessels of the nose and the brain are well-suited for brain cooling.
TEMPERATURE ACCLIMATION IN THE CENTRAL NERVOUS SYSTEM OF RAINBOW TROUT (SALMO GAIRDNERII).
TLDR
Results contrast with brain tissue respiration measurements that show that metabolic compensation is much more complete between 10 and 16° than between 4 and 10°, and significant compensation occurred in response to low temperature acclimation (4°) but not to high temperature acclamation (16°).
Mako and porbeagle: warm-bodied sharks.
TLDR
Highly developed countercurrent heat exchangers located in the vascular system of Mako and porbeagle sharks form a thermal barrier which prevents heat from being carried off by the circulating blood and lost in the gills.
Elasmobranch Central Nervous System Organization and Its Possible Evolutionary Significance
TLDR
Comparisons with bony fish and land vertebrates suggest that elasmobranchs have independently developed complex pallial fields and cerebellar foliation as a result of parallel evolutionary trends.
Influence of the carotid rete on brain temperature in cats exposed to hot environments
  • M. A. Baker
  • Medicine, Chemistry
    The Journal of physiology
  • 1972
1. Thermocouples were chronically implanted in various intracranial and extracranial structures in adult cats. Temperature of arterial blood on the proximal and distal sides of the carotid rete was
Effects of cold and heat on behavior and cerebellar function in goldfish
SummaryA similar sequence of behavioral effects was observed for either cooling or heating; most effects occurred on changing temperature of entire fish or of only the cerebellum. On moderate heating
...
1
2
3
4
...