Where is the mamary gland of dolphin?

Dolphins do not have mammary glands in the same way that humans do. They are mammals, so they do nurse their young with milk, but their mammary glands are located in the folds of skin near the genital opening, not on their chest like humans.

When the calf is ready to nurse, the mother uses muscles to force milk out of her mammary slits, which are small openings in the folds of skin. This allows the calf to suckle the milk without having to be positioned directly under the mother's belly.