Jellyfish

Despite the fact that jellyfish are not animals that we like to see up close, especially if one of their tentacles touches us, there are many different species in the marine animal kingdom. Specifically, there are more than 1.500 different jellyfish species, and the experts themselves consider that not all of them have been discovered. Many unknowns live at greater ocean depths, so new ones may be discovered in years to come.

If you want to know more about these animals and discover their characteristics, how they reproduce, what they eat... be sure to take a look at all the information we have compiled.

How are jellyfish

Jellyfish, scientifically named medusozoa, are also known as sea tears, aguamalas (or malaguas), aguavivas, aguacuajito or aguacuajada. They are pelagic marine animals, that is, they live in the oceans in the water column that is not on the continental part. Its size is usually between 5 and 40 centimeters in lengthIt depends on what species it is. There are some that are capable of reaching 200 centimeters in diameter (and also that figure in their weight).

96% of your body is made up of water. This is characterized by being gelatinous and in the shape of a bell. On it hangs what is called a "tubular handlebar." It has a mouth and a series of tentacles that are loaded with stinging cells that it uses to defend itself or to catch its prey.

In the sea it moves in a curious way since it does so through contractions in its body, taking in water and releasing it as a propeller to move. Something to note is that they can only move up or down like this, not to the sides (this depends on the ocean currents themselves, which is why they sometimes reach the beaches).

Despite being a living organism, an animal, the fact that it does not have a brain stands out. Jellyfish use nerve receptors that are what help them survive.

As for their life expectancy, it is quite different depending on the species. While some only live about 2 hours, there are other species that can do it for 6 months. And some can even live forever.

Habitat

jellyfish live in warm and tropical water areas. However, due to their adaptation, they are capable of being found in other seas and oceans with colder or warmer waters. In fact, they can withstand temperatures between -6 degrees Celsius and 31 degrees.

The usual thing is that they are in waters that are between 9 and 19 degrees. They are almost always more frequent in the Indian, Atlantic and Pacific oceans, although some species of jellyfish can also be found in the Mediterranean.

types of jellyfish

All the types of jellyfish in the seas have not yet been known, since the more than 1.500 species are not really the ones that exist, but many more that have not yet been discovered. However, some of them, the best known, are the following:

Portuguese Caravel

It is a jellyfish that differs greatly in its appearance from the most common ones, as well as in its way of life, since they like to float on the surface of the water, and have even been found in the sand on the beaches.

It is characterized by emerge in the water leaving the tentacles free and thus trapping its victims. Visually, it looks like a bag or similar, but it's actually a jellyfish.

cannonball jellyfish

It has an almost perfect round shape, white, brown or even blue in color. Although they can deceive with their appearance, because it seems that they do not have tentacles, the truth is that they do have them, only they are hidden and they only deploy them to attack their prey or defend themselves.

blue button

Its very similar to an algae, Therefore, they pose a danger when you walk on the beach or are in the water and you want to touch them to get them away from you, believing that they are not animals. Also, they are very small, but just as dangerous if they bite you.

moon jellyfish

It is one of the best known in all seas and oceans, as it has adapted well to all regions. It is also the usual species that we think of when the word "jellyfish" comes to mind since its shape is the usual one for these animals.

jellyfish sailboat

This is perhaps one of the ones that, if you come across it, don't be afraid to touch it, because, although it has poison, this is harmless to humans and visually the jellyfish is one of the most beautiful. With just a size of 7 centimeters, their blue color (in different shades), with some gold and transparent, make them very striking.

They live, like the Portuguese man-of-war, on the surface of the water, leaving their tentacles to go freely through the water to catch their food and process it inside.

Jellyfish feeding

Despite their strange shape, the truth is that jellyfish have a mouth and it is through it that they introduce their food. In addition, they also have a stomach and intestines. Their diet is based on eating other animals, that is, they are carnivorous. In fact, what they eat the most are small fish, smaller jellyfish species, crustaceans, mollusks, larvae, eggs, and yes, plankton too.

To eat, they make use of their tentacles, managing to catch their victims (and injecting them with the "poison" they carry) so that they do not escape or move. They take them to their mouth and it is inside where the process to process that animal takes place.

The reproduction of jellyfish

Jellyfish reproduction involves distinguishing male, female and hermaphrodite specimens, that is, having both sexes in the same individual. The latter is not common, but it may be the case, so they would not need another animal to carry out the process.

En general, reproduction takes place when eggs and sperm are released into the water, fecundating in this same medium. But it can also happen that fertilization takes place inside the female, introducing the sperm so that they reach the ovules.

Depending on the species of jellyfish, this process can take as little as a few minutes, or even a year or more. It can occur throughout the year, although it is in summer when there is more proliferation due to the warmer temperature and the increase in available food.

Once mating (or fertilization) takes place, the eggs are formed and they release a larva. This is called a "planula" and is pear-shaped. It stays attached to the jellyfish through its tentacles until, after a while, it separates and floats in the water until it finds something to attach to.

When it finds it, it begins its next phase, which is the polyp phase, where it begins to develop the solid parts of your body (mouth, tentacles…). This phase lasts approximately one year, at which time they will detach from the place where they have been fixed to move freely, already like jellyfish.