The blue whale is the largest type of baleen whale. The longest one was a female whale caught in Antarctic waters from 1904 to 1920. It was 33.58m long and weighed 170 tons.

Females appear larger than males, and the southern blue whale is larger than the northern blue whale.

Viewed from above, the muzzle is broad and flat.

The dorsal fin is small, about 0.4m high, located in the rear 1/4 of the body.

The flippers are smaller, accounting for 15% of the body length.

The width of the caudal fin is 1/3 to 1/4 of the body length, and the trailing edge is linear.

There are 55 to 88 sting grooves, the longest of which reaches the umbilicus.

There are 270 to 395 whisker plates on each side.

The back of the body is dark gray-blue, the belly is slightly lighter, and the mouth and whiskers are black.

Living habits: Blue whales feed on plankton and their staple food is krill.

A blue whale consumes 2 to 4 tons of food every day.

The swimming speed is 2~6km/h when feeding, 5~33km during migration, and the maximum speed per hour is 20~48km.

Generally, 10 to 20 small dives are followed by a deep dive. The interval between shallow dives is 12 to 20 seconds, and the deep dive can last for 10 to 30 minutes.

The spray mist column is narrow and straight, 6 to 12 meters high.

Blue whales reach sexual maturity at about 10 years old. Northern blue whales give birth and mate in late autumn and early winter. In the southern hemisphere, they mate in the southern winter, with July being the peak season.

The breeding season differs between the northern and southern hemispheres by half a year.

During the gestation period of 10 to 11 months, the calf is 6 to 7 meters long and weighs about 6 tons.

The lactation period lasts for half a year, and the weaning length can reach 16m.

Estimates of the maximum age range from 30 years to 80 to 90 years.