For every living individual, death is the end. However, for a population, it is not just from birth to death, the most important thing is to ensure the continuation of the population. If the mode of reproduction is not reasonable, it is likely to bring about the demise of a population. Darwin once wrote a book called "The Origin of Man and Sexual Selection", which tried to explain the evolution of living things from the perspective of reproduction. It can also be seen from this perspective that reproduction is crucial for the population.
The oceans account for 71% of the Earth's surface area, and with the depth of the oceans, it can be said that the habitable space of the oceans accounts for 99% of the entire Earth. In the vast ocean, it is very laborious to find the right partner and finally complete the entire reproductive process. You know, even the largest creature in the ocean, the blue whale, is a "small fish" that is not worth mentioning relative to the entire ocean. So the question is, how do the creatures in the ocean find their "other half", and how do they complete reproduction and continue the population?
In fact, marine organisms have adopted a variety of reproductive strategies. This time we're going to talk about an interesting marine creature: the Nassau grouper, whose reproductive strategy is a strange thing in the marine biosphere. So what's going on?
<h1>The biggest "bachelor's ball" in the ocean circle</h1>
Nassau grouper belongs to the chordate phylum - teleost fish - rayfin suborder - perch family - grouper subfamily - grouper genus - Nassau grouper, mainly distributed in the tropical west Atlantic Ocean and the West Indies of the Caribbean. Nassau groupers are medium to large fish, and adult Nassau groupers can reach about 1 meter in length and weigh up to 25 kilograms, making them one of the largest fish living in coral reefs. Their mouths are large, their bodies are particularly thick, and some Nassau groupers can also change their color according to the environment, and they can generally be seen at a depth of 100 meters to the coast.
Nassau groupers are solitary fish that feed during the day. Researchers have studied nassau grouper's lifestyle habits and reproductive strategies. The researchers found that when it comes to mating season, Nassau groupers generally begin to move from their area to the outer boundary of the reef 1 or 2 days after the full moon. So, in general, people will drive in one place to a piece of Nassau grouper, which is not common in the ocean, like a large "bachelor's ball", and the Nassau grouper who comes here is planning to breed the next generation.
Because Nassau groupers can change their color according to the environment, they often change their brown and beige mixed spots into white belly and black back, telling the difference through the stark color contrast: they are ready and ready to mate, which is actually a signal that more and more Nassau groupers will come here, and sometimes the largest or oldest Nassau grouper will lead other companions to go with them. As more Nassau groupers join, the "Bachelor's Ball" will grow in size.
Nassau groupers use a physical matching method, after a large group of Nassau groupers are assembled, all nassau groupers will hover on the seabed, as soon as the sun sets, the female Nassau groupers will jump to the surface of the sea, and the male Nassau groupers will then catch up and quickly release their sperm towards these eggs, so that these eggs fertilize, the whole process is not more than a minute, but it can complete reproduction in a very short time.
<h1>The "tragedy" of the Nassau grouper</h1>
This method allowed the Nassau grouper to once have a large population, but it also became a double-edged sword, which was used by humans. What the hell is going on?
The researchers found that nassau grouper populations have been plummeting. This is mainly because Nassau groupers always complete their reproduction at the same time, in the same place, every year. In the process of reproduction, a large number of Nassau groupers are often gathered, and they are all adults. This is a boon for fishermen. As a result, whenever the Nassau groupers focus on breeding together, fishermen will stay nearby for large-scale round-ups.
As nassau grouper populations plummet, many Nassau groupers tend to wait longer when they come to breeding areas, to put it bluntly to wait for more companions to show up before starting the bachelor's dance. But this is also used by fishermen, and the longer they wait, the longer they can hunt, the more sharp the Nassau grouper will be reduced. This vicious circle led directly to the Nassau grouper being listed as an endangered species by the International Union for Conservation of Nature in 2010. By 2016, the nassau grouper population had further decreased, making it a critically endangered species, which was 2 levels higher than the threat level of giant pandas, and was completely caught by humans.