Which one of the following animals is cold-blooded?

Animals are categorized as warm-blooded (endothermic) or cold-blooded (ectothermic) based on how they regulate body temperature. Warm-blooded animals, such as mammals and birds, maintain thermal homeostasis through internal metabolic processes [1]. Dolphins, whales, and porpoises are all cetaceans, which are water-living mammals that breathe air and are warm-blooded [3]. In contrast, cold-blooded animals like fish, reptiles, and amphibians rely on external heat sources to regulate their temperature [1]. Sharks are classified as fish and are generally ectothermic, meaning their body temperature is determined by the surrounding water [1]. While some specific species like the Great White shark exhibit regional endothermy, the group as a whole is fundamentally distinct from the mammalian options provided, which are strictly warm-blooded. Therefore, the shark is the cold-blooded animal among the choices.

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 29: Environment Issues and Health Effects > 29.3.4. Greeenwashing > p. 419
2. [2] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 9: Indian Biodiversity Diverse Landscape > Do you know? > p. 154
3. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 9: Indian Biodiversity Diverse Landscape > INI}IAN BIODIVERSITY T}IVERSE LANDSCAPE > p. 157