1. Large, some large, with a maximum size of 30 metres。
2. The “spring” breathing method is unique to whales. Breathe through the lungs and dive into the water for 10 to 45 minutes。
3. The whale is shaped like a fish, and in a perforation. The head is large, the eye is small and the ear shell is completely degraded. The neck is not obvious. The front limbs are fin-shaped and the rear limbs are completely degraded; most types have fins on their backs; the tails are horizontal and are the main moving organs。
4 - births, usually one child per birth, are breastfed with milk. But many are divided into fish, and in fact they are not fish but mammals。
The appetite of whales is high, with a blue whale eating 8-10 tons of krill a day. Blue whale mouths have a volume of 5 cubic metres, with large amounts of krill and seawater pouring in at mouths, and when closed, they squeeze the seawater out of the sutures of the lips and swallow the krill from the filters。
6. Whales are vertebrate doors, submersibles, mammalians, veritables, and contain about 98 species of embryonic mammals living in the oceans and rivers. There are more than 30 species of chinese sea. Of all species of whales, all but a few live in freshwater, and all rest in the ocean. Whales themselves are vaguely defined, and can contain all whales, as well as whales in specific sections. The whale also includes all dolphins. Cetaceans are divided into two subheadings: mysticeti and odontoceti. The species are small, but large, and the smallest known species are now more than 6 metres in length, and the world's largest animal, blue whale, is also a whale. However, the size of the tooth whale varies considerably, with the smallest species being about 30 cm in length and the largest varnish whale being 20 m or more. Whales are not fish. Whales belong to mammals。
7. Emigration is common to whales, as is the return of fish and migration of migratory birds, although time, season and location vary. Migration is an instinct and a necessity for survival, for example, when whales eat little in other seas, mainly in the antarctic, so that they must return to the antarctic. Most of the whales in the southern ocean migrate from subtropical and temperate zones, reaching the antarctic sea around november each year, where they remain for more than 100 days and embark on a return journey in the following february/march。
