Baikal seal
- The Baikal seal is the world’s only exclusively freshwater seal.
- In female Baikal seals, the breathing holes in the den are arranged according to one principle: the first is located 2–5 m from the main breathing hole, and subsequent ones are placed at increasingly greater distances.
- The Baikal seal can stay underwater for up to 25 minutes without breathing air. This is a record ability among mammals living in Lake Baikal.
- The seal lives to 50–56 years — one of the records among seals.
- The seal has 2 litres more blood than marine seals of the same size.
- The Baikal seal can reach speeds of up to 20–25 km/h, which is its maximum swimming speed in water.
- The Baikal seal is a pelagic species, meaning it spends most of its life in the water column rather than on the lake bed or at the surface.
- The seal gnaws breathing holes through ice up to 1.5 m thick with its claws.
- The Baikal seal is a pagophilic species: during periods of continuous ice cover, its life cycle is closely linked to this cover.
- It lives only in Lake Baikal and its tributaries.
Age
The Baikal seal, inhabiting the lake year-round, has a lifespan from 20 to 45 years, with the maximum recorded lifespan being 56 years, with a theoretical lifespan from 28 to 56 years. Sexual maturity occurs in the period from 4 years 5 months to 7 years 4 months. The embryo develops inside the mother for approximately nine months and does not feed independently; the pup’s eyes open at birth, and the calf is born on ice with white fur, receiving nutrition from the mother's very fatty milk and rapidly gaining weight. The puppy stage lasts from 1 to 2 months 2 weeks, after which the animal transitions to the adult stage, which swims well, dives for fish, and can remain underwater for up to forty minutes, and the duration of this stage is from 4 to 50 years.
Phenotype
The Baikal seal is a species possessing a streamlined body that helps to move quickly in water and conserve energy. In adult individuals, flippers are used for swimming, turning, and moving on ice. Sensitive whiskers have a specific color and help to find fish even in complete darkness. A pup is covered with thick white fur, which protects from the cold and helps to hide in the snow.
Physiology
The lake baikal seal measures in height from 17.8 centimeters to 4.5 meters, with a body length ranging from 1 to 1.4 meters and a mass between 49.13 and 58.99 kilograms; the species exhibits significant size variation throughout its development. During the embryo stage, the young have a body mass from 1 gram to 4 kilograms and a body length from 1 to 50 centimeters. As a newborn, the lake baikal seal’s body mass is from 3 to 20 kilograms, with a body length of 60 to 85 centimeters. The adult lake baikal seals have a body mass between 70 and 130 kilograms and a body length from 1.1 to 1.4 meters.
Habitat
The Baikal seal occupies temperate coniferous forests, which are cool with many coniferous trees and snow in winter; flooded meadows where water frequently covers the ground and there is abundant grass; taiga characterized by cold winters and numerous coniferous trees such as spruce and pine; and tundra with very cold temperatures, a short summer, few trees, and much moss. The species’ habitat includes freshwater lakes and ponds, swamps and marshes, land, highlands and tundra, and terrestrial forests. The climate features cool summers, with temperatures from 15 to 20 degrees Celsius; winters with little precipitation, but more precipitation in summer; very cold winters and very hot summers; dry and snowy winters with little rain but much snow; and summers with abundant rainfall and cool temperatures, along with snow in winter.
Shelter
The Baikal seal is found on the ice of Lake Baikal; the species uses lairs for breeding, resting, and protection from the cold. These lairs are constructed from snow, providing shelter for the animals.
Geography
Lake Baikal seals inhabit the freshwater realm and the Palearctic region, specifically the East Siberian taiga ecosystem. The species is found only in Lake Baikal, a large lake located within this region.
Feeding
The Baikal seal feeds exclusively on fish, hunting underwater and using its vision and sensitive whiskers to locate prey; the species employs an active hunting strategy, consuming fish such as golomyanka, bychki, perch, other lake fish, and small fish, including yellowtails and sig. The young are fed milk, and the daily food requirement ranges from 3 kilograms to 6 kilograms. Hunting occurs in water, and while the animal is consumed in some cultures, it is not considered halal or kosher.
Reproduction
The Baikal seal’s gestation period lasts nine months, and the female gives birth to a single pup in a snow den on ice; the mother feeds the pup with milk for about two months and protects it. The species reproduces through live birth, with pups being born alive on land, not hatching from eggs or larvae. A litter has one pup, and the female produces offspring once every year. The young reach maturity from four to eight years of age. Reproduction is always achieved through fertilization, without generation changes. The species inhabits and develops on land, outside of bodies of water, with eggs, larvae, or pups developing in nests built on land or close to it. These ground nests are located directly on the surface of the soil on land, where only the mother displays parental care.