Are Whales Mammals? A Detailed Explanation of the Differences Between Whales and Fish
Whales generally refer to the order Cetacea, which is mainly divided into two suborders, the baleen whales (Mysticeti) and the toothed whales (Odontoceti). There are fewer species of baleen whales, but they are enormous in size; even the smallest known species has a body length of more than 6 m, while the body sizes of toothed whales vary considerably, with the smallest species measuring only about 3 decimeters in body length and the largest also exceeding 20 m. Now let us take a look at whether whales are mammals!
Are Whales Mammals?
Whales are mammals. Whales belong to the phylum Chordata, subphylum Vertebrata, class Mammalia, subclass Eutheria, and are marine mammals, of which there are about eighty species. They live in the ocean and rivers; apart from a few species that live in fresh water, the rest all inhabit the ocean. Note that whales do not belong to the fish.
What Were the Ancestors of Whales?
The ancestors of whales were most likely terrestrial hoofed animals from North America, Europe and Asia——the Mesonychidae. Some members of the mesonychids were as small as domestic dogs, while others were as tall as bears, but since the evolutionary process of many animals goes from small to large, it is therefore possible that cetaceans evolved from small mesonychids. It is speculated that these mesonychids, which had few teeth and caught fish in shallow water, gradually shifted to an amphibious way of life and then, over a long evolutionary process, became today's various whales and dolphins.
What Do Whales Eat?
Whales generally feed on mollusks, fish and plankton, and some species can also prey on seals, fur seals, etc. At regular intervals they must surface to breathe. Generally, in winter they swim from high-latitude cold-water areas to low-latitude warm-water areas to give birth, and in summer they swim back from low latitudes to high-latitude cold-water areas to feed. Due to environmental degradation and heavy hunting by humans, members of the whale group, especially some of the large members, have been widely hunted because of their high economic value, and many cetaceans are already on the verge of extinction.