Jellyfish are sea creatures that are part of the Medusozoan subfamily. Here you not only can learn everything about jellyfish but also see them in the following animated images.
What are jellyfish? Jellyfish are animal organisms with a complex physiological structure that goes through a particular phase of development.
Jellyfish Animated Images
Jellyfish are a way of life and an evolutionary stage for individuals who are members of the Medusozoa subfamily. The jellyfish is not a fish since they are classified in different groups because they are different from other animals.
The body comprises a non-living gelatinous substance called mesoglea, created mainly by water (90%). This gelatine is wrapped by a layer of skin of only one cell thickness.
They weigh only a few grams because they are too light to float in water and move with currents. The size ranges from 12 – 200 cm, and the largest recorded jellyfish is about 35 m long.
Their life expectancy varies between species. Some may last a few hours, others six years, and the Turritopsis nutricula jellyfish is a species that can live forever (recently recognized capacity), as long as a predator does not hunt it.
The body is symmetrical, allowing them to locate danger or food in any direction. They lack a brain and instead have nerve receptors, and only 5% of their body is composed of solid materials.
They swim through the sea horizontally, taking advantage of currents or wind; however, they can also swim vertically.
Jellyfish’ tentacles are close to the mouth and range from four to eight (depending on the species), vary in length. The tentacles are used to catch and sting their prey.
Each tentacle is covered with skin that includes stinging cells, some sting, some grab, and some stick. The jellyfish itself produce these cells at an alarming rate, so they are disposable.
The stings have venom that is used for various purposes, such as stunning and killing their prey. For example, the sea wasp or box jellyfish from Australia has a sting capable of killing a human.
The longest tentacle is the one that produces the sting. The scientists have proven that the only part of the jellyfish can be touched without any problem, but we recommend not to play it and to flee from them when they are spotted.
The jellyfish spends its whole life in the open water. It can be found in all warm and cold seas, also in the open sea, and on the coasts. Only rare species live in freshwater.
There are also jellyfish species that prefer to stay at a shallow depth, close to the surface, while there are jellyfish that successfully live at thousands of meters deep.
Some jellyfish that live in rivers or lakes have a lot of agility to move around these bottoms as they seek to rest among the algae or rocks.
In contrast, others can barely move on the rocky bottoms because their long tentacles make their passage difficult. Seeing them so clear, we might think that they result from a mixture of air, light, and seawater.
Still, in reality, they are very greedy and permanently ingest plankton – tiny animals that live in suspension in the water – and, when they can, also little fish.
The tentacles carry the food inside the umbrella, where it is gradually surrounded and absorbed by the manubrium.
To advance in the water, the jellyfish uses the bell and the swimming paddle. By contracting the bell, it pushes the water backward, and in this way, it projects the body forward. Some colonies have individuals exceptionally gifted for swimming.