From time immemorial, people have tried to broaden their horizons, to know the world around them, to find answers to their many questions. What is the meaning of life and being? Is there a higher mind? What happens after death? The greatest minds of our planet throughout their lives have been wondering over these questions. In this article, we will consider, perhaps, not such a philosophical, more mundane, but no less interesting question. We will talk about jellyfish, and more specifically, about how jellyfish breed.
Lords of the seas
They have no brain, no bones, no blood. Nevertheless, their appearance flourished and multiplied actively. For more than six hundred million years, they have lived in the deepest and darkest corners of the ocean. Now they are crowding out various life forms in packs and destroying aquatic ecosystems. Yes, you were not mistaken, in this article we will talk about beautiful, mysterious and deadly creatures - jellyfish. If you add a little specificity - we will slightly open the veil of secrecy and talk about how jellyfish breed.
A wonderful creation of nature or a ruthless killer?
Many consider jellyfish to be absolutely safe creatures. But this is not so! They are terrible predators that feed on marine inhabitants (various crustaceans, zooplankton, caviar, etc.). Jellyfish use deadly weapons - their tentacles - in order to obtain food. Think these tentacles are completely safe for humans? No matter how. The stinging cells that are on them, in contact with human skin leave painful burns. But this is not the worst. There are rare types of jellyfish, contact with which can be fatal. These include the Sea Wasp, Portuguese boat and Nomura jellyfish.
As you can already understand, jellyfish are not as harmless as it seems at first glance. Do you doubt it? As evidence, we can cite the events that have been happening in Japan for more than 10 years. Due to the constant flood of jellyfish Nomura, the Japanese coast has already become a dead zone. What is the reason for this activity? The same question was asked by researchers from the University of Hiroshima. In order to find out what was the matter, I had to understand and study how jellyfish reproduce. But now Japanese scientists probably know that global warming was to blame. Can you imagine how the temperature increase is associated with an increase in the number of jellyfish? To understand this, you need to delve into the nature of these creatures, learn about how jellyfish breed. This article will help you with this.
How do jellyfish breed?
The males produce sperm, the females - the eggs. During the confluence of the sperm and the egg, a planula forms that settles at the bottom. What it is? A planula, or, more simply, a larva, is a phase of the life cycle of some animals. As a rule, during development, the larva lends itself to various metamorphoses and transformations. So, the jellyfish planula turns into a polyp, which is a representative of the asexual generation. When the polyp reaches maturity, young creatures begin to break away from it by budding.
The life cycle of jellyfish is a metagenesis. As you may have learned from the school biology course, this is one form of life cycle that is common to some animals. The essence of metagenesis is that asexual generations and generations that reproduce sexually are naturally alternating.
