Females mate 200 times but keep eggs for perfect partners

Let's pretend until you really do. The grouper kicks the mating hundreds of times but secretly keeps the egg until it is certain that the partner is worthy of him.

According to New Zealanders, during mating season, spring bream (Lethenteron kessleri) male and female in Siberia meet in special nests at the stream where they live. A female is said to mate up to 200 times with 10 males or more.

So far, the benefits of these marathons for the female grouper are still unclear, because they require a lot of energy. Recently Japanese researcher Itsuro Koizumi from Hokkaido University and colleagues discovered that during most mating, the grouper kicked the stream without launching eggs.

Screenshot of a stone grouper.

Potential fish did not seem to notice when the female partner tricked them by holding the eggs, according to researcher Koizumi, because they still release sperm into the water.

The female rock grouper are more likely to participate in mock mating when participating in the fun with a lot of male fish, suggesting that they are the picky fisher with more options. This is consistent with the theory that pretending to mate allows the female to choose a father for her children.

Some female and female mammals also mate with many males - a process known as a secret choice. But with females sucking, this involves sperm selection once it is actually in the female reproductive tract. The secret choice of females in species where fertilized eggs outside the body have only been recorded in a few animals.

Even so in mating marathons, rocky grouper may not choose a father for his children based on the power of the male. Instead, it may be related to how many stones males can move during the nest building, researcher Koizumi said.

The rocky grouper only develops eyes when they are mature and the females have larger eyes than the males - possibly because they need eyes to filter out the best partner.

Rocky grouper, also known as "vampire" fish has a length of 60cm to 90cm. They look like eels, but their behavior is like leeches. With a round mouth like a disc and sharp teeth, rocky grouper clings to other fish and sucks their blood and body fluids, causing them to weaken or die.