Jellyfish what kind of animal

But, as Dr. Ames points out, the differences in this case overwhelm the similarities. For a shared trait to be relevant in classifying organisms into groups, it has to have been passed down from a shared common ancestor.

Besides, there are other significant differences between these two tentacled creatures. Cephalopods have three layers of tissue while jellyfish only have two, and two openings to their digestive tracts while jellyfish only have one. Cephalopods also have large brains and other organs that jellyfish lack. This jellyfish, a member of the phylum Cnidaria, can have tentacles up to feet long 58 meters and a bell almost 7 feet 2 meters in diameter. Their closest cousins include corals and anemones.

A phylum is one of the large groupings used in taxonomical classification to refer to a group of creatures that has evolved from a common ancestor. For example, humans belong to the phylum Chordata, which includes all the organisms with backbones as well as others with backbone-related structures.

Sea turtles relish the taste of jellyfish. Some jellyfish are clear, but others are in vibrant colors such as pink, yellow, blue, and purple, and often are luminescent.

The Chinese have fished jellyfish for 1, years. They are considered a delicacy and are used in Chinese medicine. All rights reserved. Personality Quizzes. Funny Fill-In. Amazing Animals. Weird But True! The body of a jellyfish exhibits radial symmetry and is divided into three main parts: the umbrella, the oral arms around the mouth and the stinging tentacles.

They have an internal cavity, in which digestion is carried out. This cavity has a single aperture which functions both the mouth and the anus. Jellyfish are carnivores and can increase in size rapidly and procreate in large numbers when food is abundant. However, if food is scarce, they can become smaller. These animals, of a gelatinous consistency, have a very unsophisticated anatomy which is nevertheless very effective.

They feed mainly on zooplankton, small crustaceans, and in some cases, small fish and other jellyfish also form part of their diet. In order to reproduce, males and female jellyfish release sperm and eggs into the water sexual reproduction. After fertilization, they develop larvae which give rise to new jellyfish or polyps that settle on the sea floor. From these polyps, by means of asexual reproduction, new free-living jellyfish may develop. The tentacles, with their stinging cells, serve as defense and as a powerful weapon for capturing prey.

When they come into contact with their victims, the nematocysts cells loaded with poison present in the tentacles release their harpoons or filaments and release a toxic substance that paralyses the prey. The oral arms help in the capture and ingestion of the captured animal. Among the predators of the jellyfish, the following have been identified: ocean sunfish, grey triggerfish, turtles especially the leatherback sea turtle , some seabirds such as the fulmars , the whale shark, some crabs such as the arrow and hermit crabs , some whales such as the humpbacks.

Some other cnidarians such as anemones, certain nudibranches small molluscs without shells also feed on jellyfish. Some of these may even take over their stinging cells to use in their own defense. Jellyfish are classified in the Animal Kingdom within the Phylum of the Cnidarians that belongs to the sub-Kingdom of Metazoans organisms with tissues, organs and systems of organs with radial symmetry such as the jellyfish, anemones hydra and corals. Within Cnidarians, it is possible to differentiate four large groups, each with its own characteristics.

They show the phases of polyp and jellyfish alternately. They are generally small and they can be colonial or solitary. The siphonophores are included in this class. They are floating colonies of polyp individuals and jellyfish with great and abundant poisonous cells for self-defense which, in certain cases, can be lethal to humans.

The siphonophores form complex colonies of individuals specializing in different functions; some serve as the flotation organ, others for nutrition, defense or for feeling.

Among the best-known species of siphonophores, are the by-the-wind sailor Velella spirans or the Portuguese man of war Physalia physalis , which can produce painful burns for bathers, and even heart failure. This is the group of those known as true jellyfish.