Are dolphins like whales? What's the difference in appearance? Is the orca a dolphin or a whale?

When it comes to marine mammals, dolphins and whales are probably the first things that come to mind. So, did it ever occur to you that dolphins are like whales? What is the difference in appearance between the two? Is the orca a dolphin or a whale?

In fact, dolphins and whales belong to the order Cetacea. This is a kind of mammals living in water, which has the same physiological characteristics as land mammals, such as lung breathing, viviparity, etc., and has some special physiological structures evolved to adapt to the aquatic environment.

Cetaceans are the most adaptable to aquatic life of all mammals, similar to fish in shape, and can no longer live on land at all, including some of the largest animals on earth, most of which are of medium size. Members of the existing cetaceans have fin-shaped forelimbs, complete degeneration of the hind limbs, horizontal caudal fins at the tail end, vertical dorsal fins in the north, and nostrils moved to the top of the head.

The existing cetaceans can be divided into two suborders, the baleen suborder and the toothed whale suborder. Academically, the classification of these two groups is mainly based on their feeding patterns. The main morphological feature of the suborder baleen is that there are no teeth in the mouth, but there are specialized baleen, which can be used to screen plankton, so it is filter feeding. The suborder baleen, which has two nostrils, is mostly larger and includes the largest animals in the world. The tooth whale suborder, which includes most living cetaceans, has appeared since the late Pliocene, and is mainly characterized by more or less teeth in the mouth, asymmetry between the left and right sides of the skull, only one nostril and predatory. the number and arrangement of teeth will be different from that of feeding habits. There are about 79 species of 13 families in the world.

There are many species of toothed whales, most of them are small, and a few of them are very large. The distribution of many members of the toothed whale suborder is relatively limited, many species are limited to coastal areas, and some are limited to ocean or rivers, but some are worldwide and can appear in a variety of waters.

At present, there are some different opinions on the subfamilies of toothed whales, which can be divided into three distinct groups: dolphins, beaked whales and sperm whales, each of which is divided into one or more families.

In other words, dolphins belong to mammals, cetaceans, toothed cetaceans, dolphins, commonly known as dolphins, is the most species of cetaceans and people's most familiar family, a total of nearly 62 species, distributed in the world's oceans. The body length is 1.2 to 4.2 meters and the weight is 23,225 kilograms. Most of the members are smaller, including the smallest cetaceans, which feed on fish or molluscs, and some are larger enough to prey on other sea animals. In terms of appearance, the dolphin family can distinguish between long beak, short beak and no beak, most of which have dorsal fins on the back and a few without dorsal fins.

Thus it can be seen that dolphins and whales are actually called differently, just as eagles, dogs and wolves are of the same clan, similar but not the same. The small ones are called dolphins and the large ones are called whales. It is said that the dividing line is about 5 meters long after adulthood.

So, is the orca a dolphin or a whale?

Orca is a kind of large toothed whale, which is called evil whale, killer whale, killer whale and orca because of its ferocious temperament. According to the biological classification, orcas belong to the cetacea-dolphin family. If the whale refers to the cetacean, then the orca is both a member of the dolphin family and a whale.