Gliding through deep waters, these magnificent whales are the biggest marine fish and have been in existence for a long time. Earlier, these whales were seen dwelling in deep oceans. However, now on the verge of extinction, these whales are mainly found in the deeper waters of Arctic and Antarctic Oceans. They are often seen traveling in pairs and emit low frequency sounds to maintain distance among themselves. Though they dwell in cold waters, during winters they migrate to temperate waters to mate and breed. This massive blue whale obtains its physique from feeding on around 4 tons of krill every day. The following article gives you a brief idea about their anatomy. Anatomy These whales stretch up to 98 ft and weigh around 200 tons. Their long and thin body structure helps them glide swiftly into deep waters. They have a deep U shaped mouth and have a blowhole on upper surface of their head. These whales have around 300 baleen plates, each 3.2 meters long, and have 60-90 grooves that run down parallel to the body from the lower jaw. They have small dorsal fins, but the size and shape of these fins differ from one whale to the other. They come to the water surface for breathing. As it swims to the surface, it lifts its shoulders and breathes through the blowhole, which is located at the top of its head. These whales have two blowholes which are well protected under a splash guard. They have a tendency to raise their tail fins while breathing and are recorded to release a 12 meter vertical spout while breathing. The flippers of whales, which are 9.8-13 ft in length, have small spots or patches, while the color may vary from one whale to the other. The lower part of the flippers are mainly white, while the upper ones are gray. They mainly feed on tons of krill. In order to consume their favorite food, the whale opens its large mouth and swallows in plenty of water along with krill, expanding its skin that covers its throat and stomach. It then pushes out all the water through its baleen plates. These whales can weigh up to 180 metric tons and can swim at a speed of 50 kilometers per hour. They appear bluish, but their belly appears to be yellowish. As they gracefully cut through the deep waters, these whales emit sounds reaching 155 to 188 decibels, and their calls reach a frequency of 10 to 40 Hz. Winter is the time when they come together to mate. The average gestation period is 10 to 12 moths. The female gives birth once in two to three years. The calf, at the time of birth weighs about 2.5 metric tons and is 7 meters long. The process of weaning continues up to six months and the calf consumes a minimum of about 380 - 570 liters of milk. Males reach sexual maturity a little later than females. By 8-10 years of age, the males reach 22 meters in length. This is when, they are ready for mating. Females are ready to mate when they turn 5 years old and are around 21 meters in length. Being the largest living marine mammal, their anatomy is actually quite complex to understand. Their superbly built body helps them survive in the cold temperatures of the Antarctic and Arctic oceans and as well has helped them migrate to warmer zones during the peak of winter. Even though whales are known to live up to 100 years, their population has decreased due to massive hunting, oil leakages, and getting hit by ships. These all incidences have now put these species into zone of extinction.