What kind of food does the blue whale eat? How many tons do you eat a day?

The blue whale is a marine mammal belonging to the suborder baleen. There are four subspecies. The blue whale is considered to be the largest known animal on Earth, measuring up to 33 meters long and weighing 181 tons. So what kind of food do blue whales eat? How many tons do you eat a day?

What kind of food do blue whales eat?

Like other baleen whales, blue whales mainly feed on small crustaceans (such as krill) and small fish, sometimes including squid. Krill is the most numerous animal in the world and is widely distributed in the north and south polar seas. It is precisely because of such abundant food, and there is no weight limit for living in the water, so the blue whale can grow so large. The stomach of a blue whale is divided into four. The first stomach is swollen by part of the esophagus, so it has a great appetite. It can swallow about 2 million krill at a time. It eats 4000-8000kg of krill every day. If the food in its stomach is less than 2000 kg, it will feel hungry.

Blue whales feed on plankton and feed on krill (krill). A blue whale consumes 2-5 tons of food a day. The swimming speed is 2-6 km / h when feeding, 5-33 km / h in migration, and up to 20-48 km / h when being chased. Generally 10-20 small diving followed by a deep diving, shallow diving interval of 12-20 seconds, deep diving can last 10-30 minutes. The spray column is narrow and straight, 6-12m high. Krill is the main food for blue whales, and the plankton eaten by blue whales belong to different species depending on the area of the ocean. In the North Atlantic, northern krill is the main food for blue whales. In Antarctica, Antarctic krill is the main food for blue whales. The blue whale usually preys on the densest krill it can find, which means it needs to feed in deep water (more than 100 meters) during the day before it can reach the surface at night. The diving time of blue whales in the process of foraging is usually 10 minutes. Diving for 20 minutes is not uncommon, with the longest recorded diving time being 36 minutes (Sears, 1998). In the process of predation, blue whales swallow large groups of krill and large amounts of sea water at the same time. Then squeeze the abdominal cavity and tongue and squeeze the sea water through the whalebone plate. When the sea water is discharged from the mouth, the blue whale swallows the rest of the krill that cannot pass through the whalebone plate.

Life habits of blue whale

breathing

Although the blue whale lives in the sea, like other mammals, it breathes through its lungs, which weigh more than 1000 kilograms and can hold more than 1000 liters of air. With such a large lung capacity, the number of breaths is greatly reduced, only to breathe out of the water every 10-15 minutes. When breathing, you first expel the exhaust gas such as carbon dioxide from the lungs from the nostrils, and then inhale fresh oxygen. Whenever its head comes out of the water to breathe, it first expels the exhaust gas such as carbon dioxide from the body. When this powerful hot air rushes out of its nostrils, it can be ejected to a height of about 10 meters, and the nearby sea water is also swept out of the sea surface. A magnificent column of water appears on the blue sea surface, which looks like a sea fountain from afar, and makes a loud sound like a train whistle. People call it "spray tide". People can determine the position of the blue whale according to the sound it makes when it jets, the height and shape of the tide. Blue whales live in the oceans. Blue whales are rarely seen in Chinese waters, and blue whales have been recorded in the Yellow Sea and South China Sea. It usually dives no more than 100 meters, but some individuals can dive to a depth of 500 meters for 10-20 minutes, followed by 8-15 jets in a row.

Whales usually don't raise their tails before diving, but blue whales always put their tails out of the water before diving, sometimes jumping high out of the water, and then quickly diving into 30-40 meters of water in search of food. Usually it also likes to draw water with its caudal fin, which is a pastime with a variety of uses and purposes, which may be playing games, or to attract the attention of peers, or to get rid of parasites on the skin.

Activity

Although 50-60 blue whales have been seen moving in groups, they rarely form groups, most of them are lonely, or only 2-3 live together. Amphibious blue whales are very harmonious with each other, swimming, diving, foraging and breathing together, like mandarin ducks, inseparable, often leaving a wide waterway behind. The three blue whales together, mostly female and a calf, are close together, followed by males, about 3 meters apart.

Despite its huge size, slow movement and often motionless, it can rise and fall freely in the water, and its tail swings flexibly, which is not only the driving force for progress, but also acts as a rudder, with a speed of up to 28 kilometers per hour.

Make a sound

The blue whale is the loudest animal in the world, and it uses a low-frequency, deafening sound when communicating with its partners. The sound can sometimes exceed 180 decibels, louder than the sound you hear when a jet plane takes off on a runway. A sensitive instrument has detected the sound of a blue whale from 80 kilometers away. By measuring the reference pressure of 1 meter from the blue whale, it is estimated that the sound of the blue whale can reach 155-188 decibels at the source. Even taking into account the different impedance of water and air, different standard reference pressure, the equivalent sound range in air is still 89-122 decibels. For comparison, the sound of a pneumatic drill is about 100 decibels. But humans may not realize that the blue whale is the loudest animal. The fundamental frequency of all blue whale populations is 10 Mel 40 Hz, while the lowest detectable frequency for humans is 20 Hz. The sound duration of the blue whale is 10 mi 30 seconds. Blue whales off the coast of Sri Lanka have been recorded singing a four-note "song" for two minutes at a time, reminiscent of humpback whale songs. The researchers believe that because this phenomenon is not seen in other populations, it may be unique to the B.m.brevicauda subspecies.