A salmon shark’s warm-bloodedness is achieved by countercurrent heat exchange in which heat produced by internal muscle activity is used to warm the oxygenated blood returning from the gills. Salmon sharks benefit from warm-bloodedness and more efficient muscles by being able to reach higher swimming speeds.
I discovered they have a special adaptation that allows them to stay warm in cold Arctic waters: Salmon sharks are endothermic, which means they can control their internal body temperature. Most fish are ectotherms, meaning their body temperature matches the environment around them.
What is the body temperature of a salmon shark?
One physiological adaptation that makes salmon sharks such formidable predators is that they are endothermic and appear to have the highest body temperature of all sharks. Salmon shark stomach temperature measurements have been observed to maintain a relatively constant 25o C (78o F), despite changes in depth and ambient temperatures.
Most sharks, like most fishes, are cold blooded, or ectothermic. Their body temperatures match the temperature of the water around them. There are however 5 species of sharks that have some warm blooded, or endothermic capabilities.
Recent studies have shown that the salmon shark does indeed maintain an internal temperature well above ambient water temperature. In fact, the salmon shark probably has the greatest thermoregulatory ability of any shark, and internal body temperatures up to 60.1°F (15.6°C) greater than sea surface temperature have been recorded.
Are fish ectothermic or endothermic?
Osteichthyes (normal fish – perch, salmon, bass) – bony skeleton, ectothermic Amphibia (frogs) – lay eggs in water, aquatic larval stage, ectothermic Reptilia (snakes, turtles, alligators) – dry scaly skin, amniotic egg, internal fertilization, ectothermic.
You should be thinking “Are eels ectothermic or endothermic?”
Agnatha (eels) – jawless fish, no bones or paired fins, ectothermic Chondrichthyes (sharks and rays) – cartilaginous (flexible) skeleton, paired fins, ectothermic Osteichthyes (normal fish – perch, salmon, bass) – bony skeleton, ectothermic Amphibia (frogs) – lay eggs in water, aquatic larval stage, ectothermic.
Do salmon sharks eat salmon in deep water?
Much of the salmon shark’s prey is taken in deep water. However, some salmon sharks will move into shallow bays and the mouths of salmon streams to pursue salmon that are preparing to spawn.
Do salmon sharks attack from above or below?
Salmon sharks are classified as ambush/pursuit predators – they can attack from below and rely on speed and agility to catch their prey. Female salmon sharks are ovoviviparous (bearing live young after eggs hatch in the female’s body) and can birth up to five pups annually.