[Animals]Information about the largest animals on earth {whale}

[Mr.Hacker]

Whale is a common name given to various marine mammals of the order Cetaceans. The term whale is sometimes applied to all cetaceans but more often it excludes dolphins and porpoises, which belong to the suborder Odontoceti (toothed whales). This order also includes the sperm whale, killer whale, pilot whale, and beluga whale. There is another species called baleen whales (in Latin: Mysticeti) and includes filtration whales that eat small creatures after hunting them, by filtering sea water through the comb structure in the mouth called baleen. This family includes the blue whale, the humpback whale, the bowhead whale, and the minke whale. All whales have forelimbs in the form of flippers, a horizontal tail, and nostrils on the top of the head. Humans have been hunting whales for centuries for their meat and as a source of valuable raw materials such as oil for lighting.
humpback whale
Anatomy
Whales have torpedo-shaped bodies with inflexible necks, limbs modified into flippers, and a nonexistent external ear remnant. Whales also have large tails and flat heads, except for beaked whales. Whale skulls have small eye sockets, long suture points except for toothed whales and beaked whales, and eyes hanging on either side of their head. Whales range in size from the 2.6-meter (8.5-foot) long, 135-kilogram (298-pound) pygmy whale to the 34-meter (112-foot) long and 190-meter (210 short tons) blue whale. The blue whale is the largest creature on Earth. The size of many species that have sexual dimorphism favors the female more, as the females are larger than the males, with the exception of the sperm whale, whose males are larger than the females.
Toothed whales, such as the sperm whale, have teeth with cells lined with ivory. Unlike human teeth, which consist mostly of enamel on the part of the teeth outside the gums, whale teeth have cementum outside the gums. Only in large whales is cementum eroded away from the tip of the tooth and enamel is visible. Baleen whales have bones made of keratin in addition to their teeth. Baleen whales have two blowholes, unlike toothed whales, which only have one.
Respiration in whales consists of expelling air through the nostril in a strong, thick fountain, followed by inhaling fresh air into the lungs. The lungs of a humpback whale can inhale approximately 5,000 liters of air. The shapes of the blowholes vary between different types of whales, making them easy to identify.
The heart of a whale weighs about 180-200 kg. Their hearts are 640 times larger than the human heart. The heart of the blue whale is also considered the largest heart among animals, and the walls of the arteries in the heart have been described as being as thick as the length of an iPhone 6 Plus mobile phone.
All whales have a thick layer of blubber. In species that live near the poles, the skin can be up to 11 inches thick. This blubber can help increase buoyancy, which is beneficial to a 100-ton whale, and somewhat protective as predators would have a hard time getting a thick layer of blubber and the energy needed to fast when moving to the equator. Man used that fat in a way to protect him from the harsh climate. They can make up to 50% of a whale's body weight. Calves whales are born with only a thin layer of blubber, but some species make up for this with thicker layers of lint.
Whales have a two- to three-chambered stomach, similar in structure to land animals. Baleen whales have a glandular stomach as an extension of their esophagus, which helps them digest food better. Whales also have gastric chambers and pylorus.
the movement
Whales have two fins on their forehead and a fin on their tail, and the flippers have four fingers. Although whales do not have fully developed lower limbs, some species such as the sperm whale and beaked whale have separate rudimentary limbs that may include feet and toes. Whales are very fast swimmers compared to dogs, which typically move at 5–15 knots, or 9–28 kilometers per hour (5.6–17.4 mph). Whales, by comparison, can swim at speeds of up to 47 kilometers per hour (29 mph). The sperm whale can reach speeds of up to 35 kilometers per hour (22 mph). Fusion of the neck vertebrae in whales, while increasing stability when swimming at high speeds, reduces its flexibility. Whales can't turn their heads. When swimming, whales rely on their tail fin to propel them through the water in a continuous motion. Whales swim by moving their tail fin and lower body up and down, propelling themselves through vertical movement, while using their flippers mainly for steering. Some species also emerge from the water, which may allow them to move faster. The skeletal anatomy also allows whales to be fast swimmers, as most species have a dorsal fin.
Whales are adapted to dive to great depths. In addition to their streamlined bodies, they can slow their heart rate to conserve oxygen. They can also divert blood from endometrial tissues to increase water pressure to the heart and brain, among other organs. Hemoglobin and myoglobin in the bodies of whales store oxygen in the tissues of the body. Because whales have a lower concentration of hemoglobin than hemoglobin, many whales exhibit a behavior known as sounding before diving to great depths. In this behavior known as sounding, the whales stay close to the surface and make several dives to shallow depths; So that their bodies can re-store oxygen, and then make a sound while diving.
the senses

The whale's ear has specific adaptation mechanisms to the marine environment. The middle ear functions in humans to compensate for the low resistance of the outside air and the resistance of the cochlear fluid. There is no significant difference between the external and internal environment in whales and other marine mammals. Instead of sound passing through the outer ear to the middle ear, whales receive sound through the throat, which passes through a cavity of little fat before the inner ear. The whale ear is isolated from the skull by air-filled sinuses, which allow for greater directional hearing underwater. Toothed whales send high-frequency clicks from an oval-shaped organ called a melon. The melon's organ is made of fat, and the skull of any melon-bearing creature contains a distinctly shaped depression. The size of the watermelon varies between species the more they depend on it. For example, beaked whales have a small bulge on top of their skull, while sperm whales have a large melon on top of their skull.
The whale's eye is relatively small for its size, yet it retains good eyesight. In addition, the whale's eyes open on both sides of its head, so that its vision consists of two fields rather than binocular vision like humans. Whale lenses and corneas can correct short-sightedness due to refraction of light. They also contain rod cells and cone cells, which means that they can see under dim and bright light conditions, but they have rod cells in a larger amount than cone cells. Whales, however, lack short-wavelength sensitive visual pigments in their cone cells, indicating that they have limited color vision unlike most mammals. Most whales have flat eyes, large pupils that constrict as they emerge to the surface to prevent damage, slightly flattened corneas, and a transparent membrane. These eye adaptations allow large amounts of light to pass through, so the whales get a very clear picture of the area around them. Whales also have glands on their eyelids and a layer of corneal epithelium that acts as a protective layer for the cornea.

communication

Whale vocalization likely serves several purposes. Some species, such as the humpback whale, communicate using melodic sounds known as whale vocalization. These sounds can be very loud, depending on the species. Humpback whales may only communicate using so-called clicks, while toothed whales use sonar waves, which may generate up to 20,000 watts of sound (+73dB) or +43dBW, and can be heard for many miles.
Captive whales have sometimes been known to mimic human speech. Scientists have suggested that this indicates a strong desire in whales to communicate with humans. Since whales have a very different vocal mechanism, imitating human speech requires a lot of effort.
Whales emit two different types of acoustic signals, which are called whistles and clicks: Clicks are rapid, broadband pulses used for echolocation in animals, although some lower frequency broadband sounds may serve a non-ecological purpose such as communication between beluga whales for example example. The pulses fire in a clicking train at intervals of 35–50 milliseconds, and these intervals between clicks are generally slightly larger than the round-trip time of the sound to the target. The second type is whistles, which are narrow band frequency signals, and are used for communication purposes such as phone calls.
The intelligence of whales

Whales are known to learn, cooperate, plan and grieve. The cerebral cortex of many species of whales contains elongated spindle neurons, which prior to 2007 were known only to exist in embryos. In humans, these cells are involved in social behavior, emotions, judgment, and theory of mind. The location of these elongated spindle neurons in whales is similar to that of humans, suggesting that they perform a similar function.
Brain size was previously considered a major predictor of an animal's intelligence. Since most of the brain is used to maintain bodily functions, increasing brain-to-body-mass ratios may increase the volume of the cerebral cortex available for more complex cognitive tasks. Phonometric analysis indicates that mammalian brain volume measures approximately at ⅔ or 3/4 of the body mass. By comparing the brain size of a given animal with the expected brain size based on such an outgrowth analysis, a brain quotient is available that can be used as another indicator of an animal's intelligence. Sperm whales have the largest brain mass of any animal on Earth, averaging 8,000 cc (490 in) and 7.8 kg (17 lb) in mature males, compared to the average human brain averaging 1,450 cc (88 in) in mature males. Brain-to-body mass rates in some toothed whales such as beluga and narwhal whales are second only to humans.
Young whales are known to engage in complex play behaviour, which includes things like producing an underwater airy vortex or bubble rings. There are two main ways to produce a bubble ring: quickly blowing a blast of air into the water and allowing it to rise to the surface, or forming a ring and swimming repeatedly in a circle and then stopping to spiral the air in, forming eddies. Young whales also seem to enjoy biting the vortex rings, so that they explode in many separate bubbles and then quickly rise to the surface, and some believe this is one of the whales' means of communication. Whales are also known to produce bubble nets for the purpose of foraging.
Southern right whale
Larger whales are also thought to be somewhat involved in the play. For example, the southern right whale raises its tail above the water and stays in the same position for an extended period of time in what is known as whale sailing. This is believed to be a form of play and is commonly seen off the coasts of Argentina and South Africa. Humpback whales among other species are notorious for this behaviour.
life cycle

Whales are fully aquatic, which means that their behavior at birth and courtship is very different from that of terrestrial and semi-aquatic creatures. Because whales are unable to go to land to protect their young, their fetuses are born tail-first. This prevents the fetus from drowning, either at or during childbirth. Whales pump milk into the mouth of their young to feed them. Being mammals, whales have glands that make milk for their young, which are weaned at 11 months of age. This milk contains high amounts of fats which are intended to accelerate the development of lipids. It also contains a lot of fat, which is similar in composition to toothpaste. Females give birth to a single young with a gestation period of about a year, followed by care for up to one or two years, and a maturation period of about seven to ten years, which varies between species. This mode of reproduction causes few whales to have offspring, but increases the likelihood of both whales surviving. Females referred to as cows are responsible for caring for their young, while males referred to as bulls play no role in caring for the young.
Most baleen whales live in the poles. Therefore, this species migrates during the mating seasons to protect its unborn young from death due to frostbite. They stay there for a few months until their young develop enough blubber to withstand the very low temperatures at the poles. Young whales, referred to as calves until then, feed on the fatty milk of their mother. With the exception of humpback whales, the migratory season of whales is largely undefined. Most of them move from the Arctic or Antarctic to the tropics to mate, and to raise and educate the young during the winter and spring. Whales migrate back to the poles in the warm summer months, so the young can continue to grow while the mother can continue to eat, as she fasts in the breeding grounds. The southern right whale is the only exception to this type of life cycle. Whales migrate to Patagonia and western New Zealand, both of which are outside the tropics.
sleep

Unlike most animals, whales sleep conscious. All mammals sleep, but whales cannot afford to lose consciousness for a long time because they may drown. Since the ability to sleep in wild whales is limited, it has been recorded that toothed whales may sleep one side of their brains at a time, so they can swim, breathe, and avoid other predatory species and social contact during the sleep period.

A 2008 study found that sperm whales sleep in an upright position below the surface of the water when diving to shallow levels generally during the day, as the whales do not respond to passing ships unless they are in contact, leading to the suggestion that whales may be sleeping during these periods of dives.