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When people first think of mammals, they often think of elephants, monkeys, bears, and other land animals. However, there are many species of marine mammals. Class Mammals has about 6 495 species! These diverse species inhabit every land biome and every ocean around the world.
Mammals come in all shapes and sizes, and many have incredibly unique adaptations. While it is hard to believe that the naked mole rat and the gorilla are related, as mammals they share key characteristics that set them apart from other groups of animals such as reptiles or birds. In this article, we’ll look at how mammals differ from other life forms on Earth, what mammals exist in our oceans, and, above all, where whales fit into this tangled web. So are whales mammals? Let’s figure it out!
What is a mammal?
Kingdom Animalia includes the entire animal kingdom. In the animal kingdom, type Chordates includes all animals that have a notochord at some stage in their life. Inside a subtype Vertebrates (those with a spine) is a class Mammals– a class of mammals.
Mammals include three groups known as monotremes, marsupials, and eutherians (also called placental mammals). These groupings are based on several traits, most notably the animal’s reproductive system. Monotremes are egg-laying mammals, including platypuses, echidnas, and their fossil ancestors. Marsupials are mammals that give birth to babies in a pouch. Common examples of marsupials are kangaroos, possums, and Tasmanian devils. Euterians, or placentas, give birth at a relatively late stage of development and feed the offspring during pregnancy using the placenta. Eutherians have distinctive anatomical characteristics that allow for longer development and larger babies. It is wrong to call “placentals” because marsupials also have a placenta.
What makes mammals different from other groups of animals?
Mammals differ from birds, reptiles, amphibians, fish and invertebrates in three key ways.
First, all mammals have wool or wool. In some species this looks like a very prominent thick coat, while in others it may be less noticeable. For example, dolphins are marine mammals and they are no exception to this rule. Although dolphins do not have a fur coat like many other mammals, they do have hair follicles around their snouts. Dolphins have whiskers in the womb, but most of them lose them shortly after birth. The Amazon dolphin retains this whisker and uses it for sensory purposes when searching for prey. All mammals have hair or fur to some degree.
The second distinguishing feature of mammals is the presence of three bones in the middle ear, which are collectively called ossicles. The bones are the bones of the malleus, incus, and stirrup. They are located in the middle ear, behind the eardrum, also known as the eardrum. These bones are the smallest bones in the human body! They play an important role in transferring energy from the vibration of the eardrum to the inner ear. Without these bones, mammals would not be able to hear.
The third, very important feature of mammals is the presence of mammary glands. In fact, mammals are named after the Latin word for mama, which means breasts. The mother’s mammary glands produce milk for her offspring. Mammary glands are present in male and female mammals, but females experience increased development following estrogen influx during puberty. All mammals, including those in which this is not immediately visible, have mammary glands.
Mammals have many other similarities, but the key ones are the presence of hair or fur, middle ear bones, and mammary glands.
What are marine mammals?
So we know where mammals are in the animal kingdom and what makes them different from other groups of animals, but what are marine mammals? As the name suggests, marine mammals spend most of their time in the water. Marine mammals have their own list of unique adaptations to cope with low temperatures, high pressure depths, swim and breathe efficiently while living in the water.
Some marine mammals include dolphins, otters, seals, walruses, and even polar bears! Although polar bears do not live in water like dolphins, they are considered marine mammals due to the fact that they spend a lot of time in the water and rely on it for food and survival. Many marine mammals have fins or flippers rather than arms and legs like other mammals. Interestingly, the anatomy of the fins is very similar to the arm or leg of a land mammal. For example, the pectoral fins of a dolphin have humerus, radius, and ulna, just like the hands of terrestrial mammals. Marine mammals also share the same three key characteristics of mammals: hair or fur, middle ear bones, and mammary glands.
Are whales mammals?
Whales are mammals! In fact, the blue whale is the largest mammal and largest animal that ever existed! The blue whale usually weighs 220 US tonnes or 440,000 pounds. This is over 30 elephants in weight! Sperm whales have the largest brains of any existing or extinct animal species. Whales belong to the infraorder Cetaceans in class Mammals… Cetaceans include 89 species of closely related whales, dolphins and porpoises. There are species of whales that inhabit all the oceans of the world, and even species of whales that inhabit deep-sea ecosystems.
All whales have typical mammalian characteristics. Whales are placental mammals that give birth to live offspring. They have mammary glands, lactate, and they feed their young. All whales have hair follicles, although most do not grow or retain hair. They also have three middle ear bones typical of mammals. In addition, all mammals breathe air and do not have gills. Whales also breathe air, but they can remain submerged for long periods of time before needing to surface. The sperm whale can stay under water for up to 2 hours!
Whale species are incredibly diverse and have many different behaviors and adaptations. Many whales, despite their incredible size, feed on krill and small fish. However, killer whales feed on fish, sharks and other whales. There have even been reported cases of great white sharks being killed! Killer whales are some of the world’s most sophisticated hunters, and they can team up against animals much larger than themselves, such as blue whales. Sperm whales are also incredible hunters and the largest toothy predators in the world. They are the deepest diving mammals in the world and the main predators of giant squid and colossal squid.
How are the different types of whales doing today?
Whales have different conservation status depending on the species. Of the cetaceans, 7 species are vulnerable, 11 are endangered and 5 are endangered. Threatened whale species include killer whales, Mediterranean sperm whales, and blue whales. Killer whales are top predators, that is, no other animals hunt them. Thus, they are key species and play a very important ecological role, which will make their ecosystems vulnerable to destruction if they become extinct.
The main threats to whale species are whaling, by-catch and habitat destruction due to pollution and global warming. Commercial whaling – large-scale whaling for profit – has been a large industry for 17 years.th, eighteenth, and 19th centuries. The industry peaked in its most profitable year in 1853. American profits reached $ 11 million, which is the equivalent of $ 348 million today, adjusted for inflation. Despite the creation of the International Whaling Commission (IWC), the member countries of Norway, Iceland and Japan still have significant whaling industries. Whales also inadvertently end up as by-catch when the commercial fishery tries to catch other species.
Since the inception of the IWC, some whale species have begun to repopulate. The IWC has two recognized whale sanctuaries, including 11.8 million square miles in the Southern Ocean and the entire Indian Ocean south of 55º S latitude. However, the IWC is a voluntary organization that a country can leave without any obligation to stay. The Commission is also unable to enforce any laws it enacts.
Whales in captivity
Whales that are kept in captivity for human entertainment have been controversial for years. While it might seem cool to see such a majestic creature up close, whales have no place in aquariums. 176 killer whales died in captivity, not counting another 30 miscarriages or stillborn babies. Forty whales died in captivity in SeaWorld alone, and today there are 19 of them in captivity. There are currently 58 killer whales in captivity worldwide.
The conditions in theme parks and aquariums are not suitable for these beautiful animals. At the Miami Marine Aquarium, a killer whale named Lolita is kept in an aquarium that is less than twice its length at any given time. In such a confined space, she practically cannot move. In the vast majority of captive killer whales, the dorsal fin is destroyed, which means that it no longer stands upright and hangs to the side. The Whale and Dolphin Conservation Organization says it has a lot to do with swimming in small circles due to lack of space. Broken fins are incredibly rare in the wild.
Several studies have shown that the lifespan of killer whales in captivity is three times shorter than in the wild. They are more susceptible to disease in captivity, and because of the shallow depth of their reservoirs, they are more susceptible to sunburn and the development of cataracts due to UV exposure. Prolonged exposure to ultraviolet light can damage the skin of killer whales, including melanoma. A 14-year-old male killer whale named Taku was kept at SeaWorld San Antonio until his unexpected death. It was determined that he died of pneumonia, common among captive killer whales, and that he was infected with West Nile virus.
While whale watching in aquariums can be fun, don’t be sure that whales feel the same way.
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