“What Do Jellyfish Eat?” And Other Interesting Jellyfish Facts
Whether you are considering adding these alien looking creatures to your home aquarium or just are curious about them in general, eventually questions such as “what do jellyfish eat?” will come up. With their unusual, transparent appearance and their lackadaisical behavior, one might even question the fact that they are live beings, much less that they might eat any type of food. There are many fun facts about this creature that many will enjoy discovering.
Little known facts about jellyfish
One of the most startling facts about this marine species (which are also known as Medusa) is that they are not fish at all. Rather, they are members of the invertebrate genus. Unlike most living creatures, they have no brain and no heart. This may be difficult to imagine of a living creature but the Medusa has no need of such organs. They do possess a network of nerves located in the outer layer of skin called the epidermis, which allows them to feel the touch of other creatures. These transparent beings also have no circulatory, respiratory or digestive system. They are able to breathe by means of oxygenation through a process called diffusion. There is not a single bone in the body of a jellyfish, either, which explains its ability to float effortlessly and gracefully in the ocean’s currents.
Evidence points to the existence of these mysterious creatures going back over 600 million years, a history that far exceeds that of dinosaurs.
The term “jellyfish” comes from the gelatinous material that makes up the umbrella portion of the body. This goo is covered by the thin skin. The remainder of the body consists of about 95% water encased between the epidermis and the gastrodermis.
Can and what do jellyfish eat?
Like any living creature, jellyfish must have nutrition in order to survive so yes, they do eat. Though they do not have a digestive system, they do have a gastrointestinal cavity which is where all food enters and exits the body. Long, ribbon-like tentacles extend from the outer rim of the umbrella; it is these tentacles that are used to capture food. The nourishment is then pulled toward the mouth opening and into the gastrointestinal cavity. The food begins to be broken down in the cavity, with digestion completed in the gastro dermal cells. The nutrients in the food are then distributed to the rest of the body. Extraneous matter is ejected through the anus; an opening that is shared by the mouth.
A typical meal for a jellyfish might include small fish, crustaceans, zooplankton, eggs and larvae of other marine life and even other jellyfish. In truth, whatever the tentacles are able to ensnare from the ever moving ocean currents are considered as food although it may not be nutritious. Thousands of venomous cells called cnidocytes that are highly sensitive line each tentacle. These cells contain poison of varying degrees of toxicity, depending upon the species of jellyfish. At the slightest contact with a potential prey, these cnidocytes are alerted. Nematocysts, or stinging cells, are shot out and attached to the prey. The venom contained in the stinging cell is released, stunning and sometimes even killing the hapless prey so it can be drawn into the digestive tract.
People who accidentally come into contact with jellyfish by swimming or walking in waters inhabited by the creature are also prone to being stung by them. Since their transparent nature makes them difficult if not impossible to be seen in the water, encountering the tentacles is quite easy. They are unable to determine humans from a possible food source and release the stinging cells as soon as touched. Some species are deadly while others are not toxic to humans although the stings are very painful.
How do they move?
There are numerous varieties of jellyfish that display diverse characteristics. Some are very small while at least one species, the Arctic Lion’s Mane jelly, is known to have an umbrella diameter of up to 8 feet and at least 200 foot long tentacles. Certain types of the many varieties move by means of jet propulsion, but many make no concerted effort to move on their own but rather allow the current of the water to carry them.
Where do they live?
As diverse as the types and sizes of the jellyfish is the difference in their habitats. Some species are found in warm, tropical waters while others thrive in the icy depths of Arctic oceans.
Can Jellyfish be kept in aquariums?
Although keeping these marine creatures in aquariums is difficult, it is not impossible. They are often a main source of fascination among visitors at professional marine aquariums. Though they are largely invisible in their natural habitat, they can be beautiful exhibits of color and design when placed in glass containers with blue backgrounds. They are almost always displayed in cylindrical containers because jellyfish can easily become fatally trapped in corners. Water flow must extend from the bottom of the aquarium to supply lift. Temperature of the water must be tempered according to the type of jellyfish. Any enthusiast that wishes to keep them in a home aquarium must ask questions such as what do jellyfish eat, is there special care needed for the creatures and what special equipment is needed?
When wishing to keep them in a home aquarium, asking questions like what do jellyfish eat and how should they be cared for are crucial to the survival of these fascinating creatures. Learning fun facts such as these helps individuals to better understand these marine creatures.