Fin whales are the second largest mammal in the world, and in terms of body length, they are not much smaller than the blue whale, the world's largest mammal. The largest known fin whale can grow to more than 25 meters in length and weighs 74 tons. Much lighter than the same size of blue whales, because fin whales are slender and much slimmer than blue whales.
When fin whales move downstream, they act like a submarine, and their streamlined bodies allow them to effectively overcome the resistance of the current. So, they're extremely fast! It is estimated that when sprinting at full strength, their speed can be about 46 kilometers, almost like a sharp arrow off the string, so they have gained the reputation of the sea greyhound.
Like blue whales, fin whales feed on small animals in the sea such as krill and small fish, and belong to baleen whales.
Baleen whales include blue whales, fin whales, humpback whales and other whales, which are characterized by their large size, almost all of which are over 30 tons. Moreover, they have about 300-500 hundred whiskers on each side of their mouths, and with the help of these whiskers, they can filter the small animals that swallow into their mouths.
The picture below shows a baleen whale with its mouth open, looking closely at the place where the teeth were originally on both sides of the mouth, and the long whiskers are evenly distributed
Below is a frontal cross-sectional view of the beak of a fin whale
Another feature of baleen whales is that the head is larger, so the capacity of the mouth is also large. For example, fin whales can put about 70 cubic meters of seawater in their mouths, almost the same weight as their own, which is a real blood basin mouth!
In order to meet the energy needs of the body, the fin whale has at least 3 hours of time to eat every day.
Their main food is a large number of krill, when the krill colony is found, the fin whale quickly approached, opened its giant mouth, and pushed forward at a speed of about 10 kilometers per hour, dozens of tons of seawater were swallowed together with the krill in the water, and then the fin whale filtered out the seawater, kept the krill and swallowed, and each bite would eat about 10 kilograms of krill.
Because of their size, an adult fin whale may eat 1.8 tons of food a day, which means they have to eat at least 180 bites to eat.
When they're full, they gather in groups of three or five to rest or chat with whales in the distance. Fin whales have a unique vocal system that emits ultra-low frequencies of 16 to 40 Hz and is able to communicate freely with other whales hundreds of kilometers away.
Therefore, although they are far away, with this unique way of communication, they can quickly find the same kind of people in a radius of tens of thousands of square kilometers, which is very necessary for them to pass on their generations! Because, during the breeding season, they can communicate their feelings before meeting, and then choose a place to meet and talk!