When people first think of mammals, elephants, monkeys, bears, and other land animals usually come to mind. However, there are also many types of marine mammals.the class Mammalia There are an estimated 6,495 species! These diverse species inhabit every terrestrial biome and every ocean around the world.
Mammals come in all shapes and sizes, and many of them have incredibly unique adaptations. While it’s hard to believe that naked mole rats and gorillas are related, as mammals they share key characteristics that set them apart from other animal groups such as reptiles or birds. This article will explore how mammals differ from other life on Earth, which mammals exist in our oceans, and most importantly, where whales fit in this intricate web. So, are whales mammals? Let’s find out!
What is a mammal?
kingdom animal world Includes all animal life.In the animal kingdom, doors chordate Includes all animals that have a notochord at some point in their life.in yamen vertebrate (backbone) is class Mammalia– Mammal category.
Mammals include three groups known as monotremes, marsupials, and eutheria (also known as placental mammals). These groupings are based on several characteristics, mainly the reproductive system of the animals. Monotremes are egg-laying mammals that include the platypus, echidna, and their fossil ancestors. Marsupials are mammals that give birth to live young in pouches. Common examples of marsupials are kangaroos, opossums, and Tasmanian devils. Eutherians, or placentas, give birth at a relatively late stage of development and use the placenta to nourish their children during pregnancy. Eutherians have unique anatomical features that allow for longer development and larger babies. However, “placenta” is a bit of a misnomer, since marsupials also have placentas.
What distinguishes mammals from other groups of animals?
Mammals differ from birds, reptiles, amphibians, fish, and invertebrates in three main ways.
First, all mammals have fur or hair. In some species this appears as a very conspicuous thick coat, while in others it may be less so. For example, dolphins are marine mammals, and they are no exception. While dolphins don’t have fur like many other mammals, they do have hair follicles around their snouts. In the womb, dolphins do have whiskers, but most shed them shortly after birth. Amazon puffer dolphins retain these whiskers and use them for sensory purposes when hunting for prey. All mammals have some degree of hair or fur.
A second distinguishing feature of mammals is the presence of three middle ear bones, collectively known as the ossicles. The ossicles are the malleus, incus, and stapes. They are located in the middle ear behind the eardrum, also known as the tympanic membrane. These bones are the smallest bones in the human body! They play an important role in transmitting energy from the vibrations of the eardrum to the inner ear. Without these bones, mammals would not be able to hear.
A third very important mammalian characteristic is the presence of mammary glands. In fact, mammals are named after the Latin word “mamma,” which means breast. A mother’s mammary glands produce milk for her offspring. Mammary glands are present in both male and female mammals, but development increases in female mammals following the influx of estrogen during puberty. All mammals, including those that are less obvious, have mammary glands.
There are many other common traits among mammals, but the presence of hair or fur, middle ear bones, and mammary glands are key.
What are marine mammals?
So, we know where mammals fit in the animal kingdom and what sets them apart from other animal groups, but what are marine mammals? As the name suggests, marine mammals are those mammals that spend most of their time in the water. Marine mammals have their own set of unique adaptations to cope with low temperatures, high-pressure depths, efficient swimming, and breathing while living in water.
Some of the marine mammals include dolphins, otters, seals, walruses, and even polar bears! Although polar bears don’t live in the water like dolphins, they are considered marine mammals because they spend a lot of time in the water and depend on it for food and survival. Many marine mammals have fins or flippers instead of arms and legs like other mammals. Interestingly, the anatomy of the fins is very similar to the arms or legs of land mammals. For example, dolphins have a humerus, radius, and ulna in their pectoral fins, like the arms of land mammals. Marine mammals share the same three key mammalian traits: 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 the largest animal that ever lived! A blue whale typically weighs 220 US tons, or 440,000 pounds. That’s the weight of more than 30 elephants! Sperm whales also have the largest brains of any living or extinct animal species.whales belong to the suborder cetaceans in class Mammalia. Cetaceans include 89 closely related species of whales, dolphins and porpoises. All of the world’s oceans are inhabited by different species of whales, and there are even whales that inhabit deep-sea ecosystems.
All whales have typical mammalian features. Whales are eutherian or placental mammals that give birth to living offspring. They have mammary glands, lactate and nurse their young. Whales all have hair follicles, although most do not grow hair. They also have the three middle ear bones typical of mammals. Also, all mammals breathe air and do not have gills. Whales also breathe air, however, they are able to stay underwater for long periods of time before needing to resurface. Sperm whales can stay underwater for up to 2 hours!
Whales are extremely diverse, with many different behaviors and adaptations. Many whales, despite their impressive size, feed on krill and small fish. However, orcas feed on fish, sharks, and other whales. They have even been documented killing great white sharks! Killer whales are some of the most experienced hunters in the world, able to team up against animals much larger than them, such as blue whales. Sperm whales are also incredible hunters, the world’s largest predators with teeth. They are the deepest diving mammals in the world and are the main predators of giant squid and giant squid.
How are the different species of whales doing today?
The conservation status of whales varies by species. Among the cetaceans, there are 7 vulnerable species, 11 endangered species and 5 critically endangered species. Endangered whale species include killer whales, Mediterranean sperm whales and blue whales. Killer whales are top predators, meaning no other animal preys on them. As such, they are keystone species with very important ecological roles, and their ecosystems can easily collapse if they become extinct.
The main threats to whale species are whaling, bycatch, and habitat destruction from pollution and global warming.Commercial whaling—the mass hunting of whales for profit—was a huge industry in the 17th centuryday18dayand 19day century. The industry reached its most profitable year in 1853. US profits amounted to $11,000,000, which equates to $348,000,000 today (adjusted for inflation). Despite the creation of the International Whaling Commission (IWC), members Norway, Iceland and Japan still have large whaling industries. Whales are also inadvertently caught as bycatch when commercial fisheries try to catch other species.
Since the founding of the IWC, some whale species have begun to repopulate. IWC has two recognized whale sanctuaries, including 11.8 million square miles in the Southern Ocean and the entire Indian Ocean south of 55º South latitude. However, the IWC is a voluntary organization and a country can leave without an obligation to stay. The commission is also unable to enforce any laws it passes.
whale in captivity
The keeping of whales in captivity for human entertainment has been a controversial topic for years. Despite how cool it might seem to see such a majestic creature up close, whales don’t belong in tanks. 176 orcas died in captivity, not including another 30 aborted or stillborn calves. SeaWorld alone has had 40 whale deaths in captivity, compared to 19 in captivity today. There are currently 58 captive orcas in the world.
Conditions in water theme parks and aquariums are not suitable for these beautiful animals. At the Miami Seaquarium, an orca named Lolita was kept in a tank that was less than twice her body length at any point. In such a confined space, she could barely move. The vast majority of captive orcas have a collapsed dorsal fin, which means that it no longer stands upright but droops to one side. Whale and Dolphin Conservation said it was mainly due to swimming in small circles due to lack of space. Collapsed fins are very rare in the wild.
Several studies have shown that captive orcas live three times shorter than those in the wild. They are more susceptible to disease in captivity, and because of the shallower tanks, they are more prone to sunburn and cataracts from UV exposure. Prolonged UV exposure can cause skin damage, including melanoma, in orcas. A 14-year-old male orca named Taku was held captive at SeaWorld San Antonio until his unexpected death. It was determined he died of pneumonia, which is common among captive orcas, and that he had contracted West Nile virus.
While watching whales in an aquarium can be fun, don’t be so sure that whales will feel the same way.
I am broadly interested in how human activities influence the ability of wildlife to persist in the modified environments that we create.
Specifically, my research investigates how the configuration and composition of landscapes influence the movement and population dynamics of forest birds. Both natural and human-derived fragmenting of habitat can influence where birds settle, how they access the resources they need to survive and reproduce, and these factors in turn affect population demographics. Most recently, I have been studying the ability of individuals to move through and utilize forested areas which have been modified through timber harvest as they seek out resources for the breeding and postfledging phases. As well I am working in collaboration with Parks Canada scientists to examine in the influence of high density moose populations on forest bird communities in Gros Morne National Park. Many of my projects are conducted in collaboration or consultation with representatives of industry and government agencies, seeking to improve the management and sustainability of natural resource extraction.
