Bluefin tuna and mackerel sharks are considered to be endothermic fish because their
A) lateral swim muscles heat cool venous blood, thereby elevating their body temperature above the surrounding water temperature.
B) abdominal swim muscles heat cool venous blood, thereby matching their body temperature to the surrounding water temperature.
C) lateral swim muscles cool warm arterial blood, thereby elevating their body temperature above the surrounding water temperature.
D) lateral swim muscles heat cool arterial blood, thereby elevating their body temperature above the surrounding water temperature.
E) lateral swim muscles heat cool arterial blood, thereby matching their body temperature to the surrounding water temperature.

Question

Quizplus · Accepted Answer

Bluefin tuna and mackerel sharks are considered endothermic because their lateral swim muscles generate heat, which warms the cool arterial blood. This process elevates their body temperature above the surrounding water temperature, allowing them to maintain a higher level of metabolic activity and efficiency in colder waters.

Bluefin Tuna and Mackerel Sharks Are Considered to Be Endothermic