What Do JellyFish Eat?

What do jellyfish eat?

Jellyfish have existed on planet earth even before the age of dinosaurs. There are more than 200 different species of jellyfish inhabiting the oceans. Some of them are even found in fresh water. Jellyfish are found in all oceans, at varying temperatures and depths.

Jellyfish derive their name from their jelly like main body. The bell-shaped jellyfish body has long tentacles attached to it. The lack of skeletal system gives them an unusual appearance, as documented in our jellyfish pictures. The brain-less jellyfish is amusing to watch.

Jellyfish are carnivorous and ravenous eaters. The mouth of the jellyfish is located underneath the bell-shaped body. Its simple digestive system consists of a gastro vascular cavity attached to the oral opening, which does the function of the stomach.

The same opening under the body that serves as its mouth is used for releasing excreta from the body. The food entering the opening is digested in the cavity attached to it. The waste matter generated is expelled through the same opening.

Jellyfish normally eats whatever their long tentacles catch while drifting in the ocean currents. A few species of jellyfish like the box jellyfish are good swimmers and chase their prey. The main food sources of jellyfish are smaller fishes, eggs and larvae of sea creatures and zooplankton. The larger species of jellyfish eat crustaceans and other jellyfish.

The tentacles are the main devices to catch prey for jellyfish. These tentacles have thousands of cnidocytes with stinging capsules or nematocysts containing venom. Even though these creatures are brainless, their nervous system is highly developed. When the tentacles touch a potential prey, the cnidocytes are activated immediately. They shoot nematocysts at the prey, which attach itself to the skin of the prey. The venom present in these nematocysts is released, which in turn stuns the prey.

The shocked prey is caught by the arms surrounding the oral opening and brought to the mouth. The food is digested immediately in the chamber attached to the opening and nutrients absorbed by the body. The waste is discharged through the same opening.

Many species of jellyfish are passive hunters and wait for their prey to come to them. They have sticky tentacles and drift along the currents waiting for a prey to get trapped in the tentacles. They eat mostly zooplankton, eggs and larvae of other marine creatures and crustaceans.

Some species of jellyfish are aggressive hunters and they are equipped with potent venom in their tentacles. This venom when ingested in the prey either paralyzes or kills it. This group of jellyfish preys on smaller fishes, crustaceans and even other jellyfishes. Some jellyfish is known to eat other jellies as large as themselves. Learn more about poisonous jellyfish.

Some species of jellyfish like the spotted jellyfish are filter feeders. They consume large quantities of seawater and absorb the food present in it. The spotted jellyfish is known to cause havoc in the marine life by consuming large quantities of useful zooplankton. They are also known to devour eggs and larvae of commercially important marine animals like shrimps and oysters. Source