Jellyfish – Marine Animals

The jellyfish are marine animals with gelatinous bodies, have unique characteristics and have a very varied type of food.

The jellyfish (Medusozoa) are marine animals, invertebrate beings belonging to the Cnidaria phylum, are pelagic, gelatinous, bell-shaped body from which a tubular handle hangs, with the mouth and at the lower end, sometimes prolonged by long tentacles loaded with urticant cells called cnidocytes. These animals appeared about 500 million years ago.

The jellyfish live in the sea, so they fall into the category of marine species, and as has been recorded, during all the time they have in our world, which is not little, they have lived there since they have adapted to the perfection to this medium and only need to approach the coasts or places with rocks for their reproductive cycle.


The anatomy of a jellyfish will change relatively according to the species that is being talked about, since there are several species, classified from their shapes and colours, even in behaviour when living in water. A specific fact of these is that they have a hole in the middle of their bell through which they eat food and also defecate.

For example, venom is another of the main characteristics of the Cnidaria family, which use stinging cells called cnidocytes that harbour a variety of very potent toxins that make their prey in a few seconds paralyzed and even dead. Although most of the jellyfish species that exist in the world are not deadly to humans, it is true that many of them can kill a person in a matter of minutes or hours, which means you have to prevent the bites, since it can cause you very serious damages and even death.

Feeding the jellyfish

The jellyfish feed mainly on plankton, crustaceans, fish eggs, other jellyfish and small fish, so they are considered carnivorous animals. They have a hole in the middle of their bell that ingests food and also defecates.

They hunt passively and use their tentacles as a network, a way that facilitates hunting is their way of swimming, because when they move they make a greater number of prey closer to their tentacles.

Jellyfish predators

Its main predators are other species of jellyfish, although they can also be prey for tunas, sharks, swordfish, sea turtles and some of the Pacific salmon species.

Sometimes, it is likely that some seabirds feed on these jellyfish, but only by accident, because their real purpose is to capture the crustaceans that adhere to the bell jellyfish.

Jellyfish habitat

Most jellyfish are sea animals, but there are also freshwater species. To mention the Hydromedusae, whose most notable example is the cosmopolitan freshwater jelly Craspedacusta sowerbii, whose diameter is less than 2.5 cm and whose body does not have any coloration. There are also populations that only inhabit the lakes, such as the jellyfish of the lakes in Palau.

Jellyfish - Marine Animals

They can inhabit the same near the plankton as at the bottom of the sea. The medusa of the reverse of the genus Cassiopea usually remains at the bottom of shallow lagoons. Other jellyfish, such as the Staurocladia and Eleutheria, find it almost impossible to move or swim with their tentacles through rocky bottoms or algae buds.

A good part of the Hydromedusae and Scyphomedusae that live on the coasts, can be seen in the bottom to stop swimming and resting for a while. The Stauromedusae can be found attached to any firm element of the seabed, such as algae or rocks.


Source: La Verdad Noticias