The reproductive organs of whales are hidden in the body

On today's planet, the largest animal in size is the blue whale, but the blue whale's eggs are not the largest. The right whale's eggs weigh 500 kilograms, 20 times heavier than the blue whale's eggs, making it the heaviest animal with the heaviest eggs in the world.

So the question is, what is the use of the right whale having larger eggs? (The whale's reproductive organs are hidden in its body and usually invisible).　　

Right whales

Right whales are baleen whales, they do not have formed teeth, only teeth like combs, these teeth are called baleen plates.

Right whales have 200-300 baleen slats at each end of their mouths. This causes them to be unable to hunt by tearing each other, and can not tear the larger prey into pieces, can only swallow the prey whole, so their main food is a variety of small fish and shrimp, and only like a large gathering of small fish and shrimp is its prey, a single small fish and shrimp does not attract its attention.

When hunting, right whales will swallow small fish and shrimp mixed with seawater, which will then be filtered out through comb-like teeth and the small fish and shrimp will be left in the mouth to enter the digestive system.

Because of the large size of right whales and their high demand for food, it is impossible to support groups of right whales in local waters, so in most cases, right whales will survive alone, with only their calves living with their mothers.

Right whales reach sexual maturity at about 10 years of age and then breed every three years, during which time they gather in a bay to find a mate.

Unlike most animals, the mating process does not involve fierce fighting; almost all males are allowed to mate, and each female right whale will also mate with multiple males.

This is very rare in nature, knowing that male lions in lions will fight for the right to mate, and only the victorious lion king can mate with the females in the population.

Male right whales can obtain mating rights without same-sex competition, meaning that many males have the opportunity to keep their offspring. However, although females will mate with multiple males, females will only reproduce once every three years or so, producing only one calf at a time, which means that many males will mate with females, but they may not always be successful in leaving offspring, and to do so, the male's sperm will need to compete fiercely within the female's body, which is called internal reproductive competition.

Reproductive competition

Reproductive competition is ubiquitous, and many animals have adopted an in-viva competition strategy. For example, in chimpanzees, females mate with multiple males during estrus. Of course, males will defeat other males before they can mate with females to gain access to mating.

But the male will leave the female after mating, resulting in the female will also have sex with other males, so that the male's sperm will again compete in the female's body.

For sperm, the female's body is not a suitable environment for survival, it maintains a weak acid environment, which can corrode sperm and cause them to die.

Secondly, the mucus in the female's body blocks the sperm and at this step, a large number of sperm are blocked by the mucus and cannot proceed to the next step. Even if some lucky ones encounter the egg cell, there is still a membrane on the surface of the egg cell and to get through it, it takes about 10 or so sperm to release the enzymes they carry, the only time one sperm will enter it, and once the sperm gets inside the egg cell, the egg cell turns into a fertilized egg and closes the outer membrane, making it impossible for other sperm to enter.

The first of these is the one in which the sperm is consumed to have a chance to combine with the egg cell, which will lead to a higher chance of reproduction for those who produce more sperm, which is why the chimpanzees have relatively larger balls.

Organisms that use in nitro reproductive competition alone usually have smaller balls. For example, although gorillas are physically strong, their balls are very small. This is because gorillas can expel males by force and dominate all females in the population so that they can get females pregnant with their offspring even though they produce a limited amount of sperm.

The reason why the eggs of right whales are as high as 500 kg is partly that they are very large, adult individuals can reach 50-90 tons, and partly because when they mate, war does not break out between the males, but each will have the opportunity to mate with females, who only produce one litter at a time, which makes the competition for sperm extremely fierce, leading to the fact that only the production of a greater number of males will have a chance to leave offspring. Under this survival pressure, right whales have evolved such huge eggs.