Whale Cetaceans

Anatomy
Like all mammals, whales breathe air, are warm-blooded, nurse their young with milk from mammary glands, and have body hair.
Beneath the skin lies a layer of fat called blubber, which stores energy and insulates the body. Whales have a spinal column, a vestigial pelvic bone, and a four-chambered heart. The neck vertebrae are typically fused, trading flexibility for stability during swimming.