Spiders keep growing until they die

5 animals that mate to death

Parasites from the order of the fan-winged, for example, produce between 1,000 and 750,000 larvae in their first and only mating season.

They are animals with a strange lifestyle: the females bury their bodies in a host, for example a lonely bee, and never leave it again. Since they have no use for wings, eyes, legs, or antennae, the females retain features from early stages of development and therefore look like mini marshmallows.

The only part of the body that peeps out of the host is the brood canal - an opening through which the male fertilizes the female and through which the larvae crawl out.

The males, which live up to six hours, fly around looking for such buried females. They mate with them and then die, says Kathirithamby. After the larvae hatch from the female, the female also dies.

Mysterious mating of eels

Fish are known for their fertility and large clutches.

Pacific salmon die after spawning, but their largest species, the king salmon, lays up to 5,000 eggs.

American eels can produce up to 30 million eggs at one time, but their sex life is still a mystery, says John Casselman, a professor at Queens University in Ontario, Canada.

These eels sometimes only reach sexual maturity after 20 years. Then they swim into the Sargasso Sea. So far, scientists have not been able to observe the process of spawning, but suspect that it happens at great depths. However, they have seen schools of eel larvae coming from this direction.

The American eel is now endangered by various factors such as overfishing and the blocking of its habitat by dams. Therefore, it may well be that we will never be able to reveal its mating secrets.