What does coelenteron mean?
The coelenteron is the single internal cavity found in the bodies of cnidarians (such as jellyfish, sea anemones, and hydras) and ctenophores (comb jellies). It functions as a combined digestive tract and circulatory system: food is captured by tentacles and taken into this cavity, where enzymes break it down, and digested nutrients then diffuse directly to surrounding tissues. Because these animals lack separate circulatory and digestive organs, the coelenteron performs both roles, and in many species its fluid also provides internal pressure that helps maintain body shape. The term derives from Greek roots meaning 'hollow intestine' and belongs chiefly to formal zoological writing. It is essentially equivalent to the more general term 'gastrovascular cavity' when applied to these radially symmetrical creatures, though it should not be confused with the coelom, a true body cavity found only in bilaterally symmetrical animals.
nounIn cnidarians and ctenophores, the single internal cavity that serves both digestive and circulatory functions; the gastrovascular cavity of a coelenterate.
- The gastrovascular cavity within the body of a coelenterate (a cnidarian or ctenophore), functioning in digestion, circulation, and sometimes as a hydrostatic skeleton.
"The researcher injected a dye solution into the coelenteron to trace nutrient distribution through the animal's body."
"Food particles are broken down inside the coelenteron by enzymes secreted from the gastrodermis."
"In hydra, the branching coelenteron extends into each tentacle, distributing nutrients throughout the body."
Standard English plural; rarely needed since discussions typically concern one organism at a time.
"Comparisons of coelenterons across species reveal differences in the complexity of gastric filaments."
Despite the name sounding like it contains a 'coelom', the coelenteron isn't one at all — jellyfish never got a true body cavity.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of coelenteron
Coelenteron comes from New Latin, formed from the Greek elements koilos ('hollow') and enteron ('intestine' or 'gut'), literally meaning 'hollow gut'. It was adopted in nineteenth-century zoological literature alongside the broader taxonomic label Coelenterata, which grouped together what are now classified separately as cnidarians and ctenophores. Related terms sharing the same roots include enteron (the alimentary canal) and coelom (from koilos alone).
Related word forms
How coelenteron is actually used
A technical term used almost exclusively in zoology and comparative anatomy. It applies specifically to the diploblastic animals once grouped as Coelenterata — modern cnidarians and ctenophores — and is largely synonymous with 'gastrovascular cavity' in that context.
Easily confused with coelenteron
The coelom is the fluid-filled body cavity found in annelids, molluscs, chordates and other bilaterians, whereas the coelenteron is the gastrovascular cavity of radially symmetrical animals such as jellyfish.