jellyfish
Sign in to savethumb|Spotted jelly|Spotted jellies swimming in a Tokyo aquarium Jellyfish, also known as sea jellies or simply jellies, are the medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals, although a few are anchored to the seabed by stalks rather than being motile. They are made of an umbrella-shaped main body made of mesoglea, known as the bell, and a collection of trailing tentacles on the underside.
AI overview
Jellyfish are free-swimming sea creatures made up of a bell-shaped body and trailing tentacles, belonging to a major group of gelatinous animals called Cnidaria. They matter because they are abundant marine animals that play a significant role in ocean ecosystems, though the provided context does not specify additional details about their ecological or practical importance.
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Article
37 sectionsContents
- Names
- Mapping to taxonomic groups
- Phylogeny
- Definition
- Medusozoan jellyfish
- Taxonomy
- Fossil history
- Anatomy
- Box jellyfish eye
- Evolution
- Utility as a model organism
- Characteristics
- Comparison with other organisms
- Evolution as a response to natural stimuli
- Largest and smallest
- Life history and behavior
- Life cycle
- Lifespan
- Locomotion
- Ecology
- Diet
- Predation
- Symbiosis
- Blooms
- Habitats
- Parasites
- Relation to humans
- Fisheries
- Products
- Biotechnology
- Aquarium display
- Stings
- Mechanical issues
- See also
- References
- Further reading
- External links
thumb|Spotted jelly|Spotted jellies swimming in a Tokyo aquarium Jellyfish, also known as sea jellies or simply jellies, are the medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals, although a few are anchored to the seabed by stalks rather than being motile. They are made of an umbrella-shaped main body made of mesoglea, known as the bell, and a collection of trailing tentacles on the underside.
Via pulsating contractions, the bell can provide propulsion for locomotion through open water. The tentacles are armed with stinging cells and may be used to capture prey or to defend against predators. Jellyfish have a complex life cycle, and the medusa is normally the sexual phase, which produces planula larvae. These then disperse widely and enter a sedentary polyp phase which may include asexual budding before reaching sexual maturity.