Question

the tiger shark and the swordfish are ectothermic (cold - blooded) fish, whereas the shortfin mako shark and the atlantic bluefin tuna are regional endotherms - they retain metabolic heat resulting in body temperatures above the ambient water temperature. modeling the effect of falling ambient temperatures on ectotherms indicated to researchers haley r. dolton and colleagues that ectotherms body temperatures inexorably decrease toward the ambient temperature. data from wild basking sharks show their body temperatures also decline as the ambient temperature falls, but consistently remain 1.0 to 1.5°c above ambient. this suggests that given a constant ambient water temperature, the basking shark will typically have 13 mark for review which choice most logically completes the text? a a body temperature very near both that of the shortfin mako shark and that of the atlantic bluefin tuna. b a stable body temperature that exceeds both that of the tiger shark and that of the swordfish. c a substantially more variable body temperature than both that of the shortfin mako shark and that of the swordfish. d a body temperature equal to the surrounding water temperature, unlike the body temperatures of the tiger shark and the atlantic bluefin tuna.

Explanation:

The text states that tiger sharks and swordfish are ectothermic fish, while shortfin mako sharks and Atlantic bluefin tuna are regional endotherms. Regional endotherms can maintain metabolic heat resulting in body temperatures above the ambient water temperature. Ectothermic fish like tiger sharks have body - temperatures that are more closely related to the ambient water temperature. So, the body temperature of tiger sharks and Atlantic bluefin tuna would be expected to be equal to the surrounding water temperature as they are ectothermic.

Answer:

D. a body temperature equal to the surrounding water temperature, unlike the body temperatures of the tiger shark and the Atlantic bluefin tuna.