Eyestalk

Eyestalk
Pulmonate land snails usually have two sets of tentacles on their head: the upper pair have an eye at the end; the lower pair are for olfaction.

In anatomy, an eyestalk (sometimes spelled as eye stalk or known as an ommatophore) is a protrusion that extends the eye away from the body, giving the eye a better field of view than if it were unextended. It is common in nature and in fiction.

In nature

Well-developed eye of Eustrombus gigas on eyestalk. There is a small tentacle on the eyestalk also.

In nature, eyestalks are sometimes called tentacles, and may have olfactory organs and/or eyes at the end. Examples include snails, the trilobite superfamily Asaphoidea, and fly family Diopsidae. The crustacean family Polychelidae have eyestalks but no eye.

In fiction

A beholder is a fictional character that sports numerous vertical eyestalks. Many Dalek variants have a horizontal eyestalk.

Tripods from Star Wars have eyestalks.

References


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Look at other dictionaries:

  • Eyestalk — Eye stalk , n. (Zo[ o]l.) One of the movable peduncles which, in the decapod Crustacea, bear the eyes at the tip. [1913 Webster] …   The Collaborative International Dictionary of English

  • eyestalk — [ī′stôk΄] n. a movable stalk with a compound eye at the tip, as in lobsters, shrimps, snails, and certain other crustaceans and mollusks …   English World dictionary

  • eyestalk — a moveable, elongate peduncle bearing an eye at the tip, e.g. in the larvae of Idiacanthidae. Placodermi and Chondrichthyes have an eyestalk, a small cartilage linking the eyeball to the braincase …   Dictionary of ichthyology

  • eyestalk — noun Date: 1854 one of the movable peduncles bearing an eye at the tip in a decapod crustacean …   New Collegiate Dictionary

  • eyestalk — see ocular peduncle …   Dictionary of invertebrate zoology

  • eyestalk — /uy stawk /, n. Zool. the stalk or peduncle upon which the eye is borne in lobsters, shrimps, etc. [1850 55; EYE + STALK1] * * * …   Universalium

  • eyestalk — noun A motile stalk having an eye at the tip Syn: ommatophore …   Wiktionary

  • eyestalk — A pre segmental appendage on either side of the median line of the carapace and bearing on its distal surface the cornea [Ingle, 1983]. Articulating eye comprising peduncle and (usually) pigmented cornea [Poore, 2004]. Peduncle movably… …   Crustacea glossary

  • eyestalk — eye•stalk [[t]ˈaɪˌstɔk[/t]] n. zool. a stalk or peduncle upon which an eye is borne, as in a lobster or shrimp • Etymology: 1850–55 …   From formal English to slang

  • eyestalk — /ˈaɪstɔk/ (say uystawk) noun the stalk or peduncle upon which the eye is borne in lobsters, shrimps, etc …  

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