Freshwater seals! Well, that doesn’t really sound true but they do exist. These seals go by the name ‘Nepra’ and are found in only one location in this entire world. Wondering how they look like and what are their physical features and lifestyle habits? Continue reading to find out some amazing Nerpa seal facts. We are sure they will fascinate you!
|Binomial Name||Pusa sibirica OR, Phoca sibirica|
|Average Length||4 feet 3 inches (1.3 meters)|
|Litter Size||1 but sometimes the females give birth to twins|
|Weight||Average 70 kilos but can reach 150 kilos|
|Average Diving Time||20 minutes to 25 minutes|
|Maximum Diving Time||70 minutes|
|Primary Food||Golomyankas or Baikal Oilfish|
|Gestation Period for Females||9 months|
|Sexual Habits||Slightly Polygamous|
|Territorial Nature||Slightly Territorial|
|Natural Predator||Brown Bear|
|Future Threat||Global Warming|
Amazing Nerpa Seal Facts: 1-5
1. Lake Baikal (which is the largest, oldest and deepest freshwater lake in the world) in Russia is the only freshwater body in this world where seals live. The zoological name of these seals is Pusa Sabricia. They are the only species of seal which live in freshwater. They are also commonly known as Nerpa.
2. The ancestors of this species are not known accurately. However, it is assumed that they originated from Ringed seals (Phoca hispida) and they were geographically isolated with the Ringed seals around half a million years back. This is one of the hypotheses of the scientists, which is called as Arctic Origins hypothesis.
3. The other hypothesis, The Paratethyan hypothesis assumes that the phocine seals made their way from south to the Lake Baikal through the Caspian Sea.
4. Irrespective of the hypothesis put forward, it is a mystery for scientists and common people about how the Nerpas reached Central Asiatic waters when their counterparts were in the northern Arctic region.
5. Scientists assume that they were propelled by the polar ice during the ice age when the ocean’s water entered the mouth of River Tunguska through the Yensei valley.
Amazing Nerpa Seal Facts: 6-10
6. They are famous for swimming upstream a river. They are also known for the travelling and changing from one river to another river.
7. There are chromosomical and genetic proofs as well to know that the Nerpas are related to other arctic seals.
8. They are the world’s smallest pinnipeds (a carnivorous aquatic animal of the order Pinnipedia). They, in fact, are the only pinniped species that is present in the freshwaters.
9. The adults are of 1.2-1.4 metres long and weigh around 63-70 kilos. The males are bigger than females. Seal-calves or the young ones are 4 kg at birth and 65cm long.
10. They reach sexual maturity at different times. Females attain sexual maturity from 3-6 years and males from 5-7 years. They live for more than 50 years.
Amazing Nerpa Seal Facts: 11-15
11. They can hold their breath for about 70 minutes! It is because of two reasons. The first reason being the extra 2 litres of blood present in their body and the second being the extraordinary capacity of their blood to hold oxygen for longer time. Because of this, they can dive up to 300 metres of depth.
12. This species of seal is more graceful than seals of other species especially females.
13. Nerpas usually hunt at nights and they use their vibrissae (the hair present on their mouth and face) to track their preys.
14. Their favourite food is the golomyanka fish and bullheads. The reason for the night hunts is the availability of golomyanka fish.
15. Nerpas are blamed for the decline in the population of a fish species known as omul fish but unfortunately that isn’t true. Contrary to what people think, they eat golomyanka and increase the chances of living for omul fishes.
Amazing Nerpa Seal Facts: 16-20
16. Adults eat around 3-4 kg of food every day. This might look little but if you see it annually one Nerpa consumes around a ton of food!
17. Baikal seals are famous for maintaining breathing and haulout holes. Adults maintain one primary hole and other accessory holes whereas the juveniles or the young ones have only one hole.
18. These holes are called as lairs. These lairs are hidden by snow-drifts or ice mounds. This is where they rest being away from the predators.
19. They breed during the months of February-March and the pups are born in the ice dens created by the female seals.
20. Pregnant females come out of the lake during winters whereas the males prefer to stay in waters in their breathing holes.
Amazing Nerpa Seal Facts: 21-25
21. On an average a female Nerpa can give birth to 20 pups in her lifetime. The gestation period is 11 months. After that the female nurse the young ones for about 2-2.5 months.
22. The Nerpa seal calves are born in late winter or early spring.
23. Nerpas living in the southern part of the lake are small because as pups they get separated from their mothers because the mothers give birth to premature babies. The reason behind this in the southern part of the lake, the ice breaks up and forces the females to wean earlier than the usual time.
24. Usually the female gives birth to one pup. But the Nerpas are one of the two species which has the chance of giving birth to twins. The twins remain together for some time after delivery.
25. The seals attain different colours during different times. Moments after birth, they are of yellow-green colour and at the time of two weeks, they become white. Adults have silver-grey skin. This is one of the differences between the Nerpa and other seals.
Amazing Nerpa Seal Facts: 26-30
26. They are often hunted down by poachers, local people and brown bears.
27. They were hunted down for their fur, soft meat and fat. They were used as an item in barter system and were also considered as talisman.
28. The number of Nerpas are declining rapidly. From 104,000 in 1994 their population decreased to mere 60,000. The mortality rate in the seal-calves has increased three times the number it was before.
29. There are many reasons for the decline. The poachers, pollution, Canine distemper Virus (a virus which is infecting the seals transmitted from dogs and other terrestrial mammals) etc. are all responsible for the decline. The seals are rapidly ageing as well.
30. Irrespective of their alarmingly high rate of decrease in population, International Union for Conservation of Nature (IUCN) listed the Nerpa in Least Concern in its Red list. Least Concern animals are not qualified as threatened, or near threatened or conservation dependent.