Operculum (animal)

A live individual of the sea snail Rapana venosa retracted into the shell, with the operculum closing the aperture
Firing sequence of the cnida in a hydra's nematocyst[1]
     Operculum (lid)
     "Finger" that turns inside out
/ / / Barbs
     Venom
     Victim's skin
     Victim's tissues

An operculum (animal) is an anatomical feature, a stiff structure resembling a lid or a small door that opens and closes, and thus controls contact between the outside world and an internal part of an animal. Examples include:

See also

A structure in ammonites which usually consists of two plates, and which was long thought to be a form of double operculum, but which more recently has been proposed to have been a jaw mechanism.

References

  1. 1.0 1.1 Ruppert, E.E., Fox, R.S., and Barnes, R.D. (2004). "Cnidaria". Invertebrate Zoology (7 ed.). Brooks / Cole. pp. 112–124. ISBN 0-03-025982-7.
  2. Ruppert, E.E., Fox, R.S., and Barnes, R.D. (2004). "Gastropoda". Invertebrate Zoology (7 ed.). Brooks / Cole. pp. 309–313. ISBN 0-03-025982-7.
  3. Hinde, R.T., (1998). "The Cnidaria and Ctenophora". In Anderson, D.T.,. Invertebrate Zoology. Oxford University Press. pp. 28–57. ISBN 0-19-551368-1.
  4. Zombori, Lajos (1999). Dictionary of Insect Morphology. Walter de Gruyter. p. 164. ISBN 3110148986.