Black calf belongs to the genus Black calf of Dolphinidae, which is a second-class protected animal in the appendix of CITES of Washington Convention. Black whale is a large toothed whale with a slightly round head, inconspicuous beak, high and upright dorsal fin, black and white body, slender mouth, sharp teeth and fierce temperament. It is a carnivore. It is a highly socialized animal, distributed in all marine areas.

The black whale's head is round, with no protruding snout, and its nostrils are on the right side of the head, with a flap that can be opened and closed freely. When they float to the surface of the water, they open their flaps to breathe, and spray foam-like aerosols, which turn into water columns when they meet the cold air on the sea surface. The forelimbs become a pair of fins, which are very developed, and the hind limbs degenerate and disappear.

shark

Sharks belong to the family Sharidae. Nicknamed grey mackerel and grey mako shark, they belong to cartilaginous fish and are called wolves in the sea. Sharks have small shield scales on the body surface and lateral lines on the body side, and their body length is about 1 to 20 meters. The bones of the whole body are cartilage, the skull and spine are calcified, and there is no seam in the skull. The maxilla and mandible have developed sharp teeth, and there are/kloc-0 pairs of nostrils in front of the mouth. Branchial fissure is located on both sides of the head without gill cover.

Sharks have other organs besides human facial features. Sharks have a keen sense of smell. It is particularly sensitive to the smell of seawater, especially to the smell of blood. The low-frequency vibration or a small amount of bleeding caused by the irregular swimming of injured fish can attract it from a distance, even exceeding the sense of smell of land dogs.