spiracle

American  

[spahy-ruh-kuhl, spir-uh-] / ˈspaɪ rə kəl, ˈspɪr ə- /

noun

1. a breathing hole; an opening by which a confined space has communication with the outer air; air hole.

2. Zoology.

   1. an aperture or orifice through which air or water passes in the act of respiration, as the blowhole of a cetacean.

   2. an opening in the head of sharks and rays through which water is drawn and passed over gills.

   3. one of the external orifices of the tracheal respiratory system of certain invertebrates, usually on the sides of the body.

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spiracle British  

/ ˈspaɪərəkəl, spɪˈrækjʊlə, ˈspaɪrə- /

noun

1. any of several paired apertures in the cuticle of an insect, by which air enters and leaves the trachea

2. a small paired rudimentary gill slit just behind the head in skates, rays, and related fishes

3. any similar respiratory aperture, such as the blowhole in whales

4. geology a protrusion of sediment into a lava flow, formed by the explosive transition of water into steam

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spiracle Scientific  

/ spĭr′ə-kəl,spī′rə- /

1. An opening through which certain animals breathe, such as the blowhole of a whale or one of the openings in the exoskeleton of an insect.

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Other Word Forms

• prespiracular adjective
• spiracular adjective
• spiraculate adjective

Etymology

Origin of spiracle

1300–50; Middle English < Latin spīrāculum air hole, equivalent to spīrā ( re ) to breathe + -culum -cle ²

Example Sentences

The skull of Elpistostege contains a clue: at the back of the head is a pair of large holes called spiracles.

From Scientific American

Colosteids lacked spiracles and breathed solely through their gills using water taken up through the nares.

From Nature

They breathe through tiny tunnels from exterior holes called spiracles that allow the air to flow through tunnels into their bodies.

From New York Times

They breathe through spiracles — small holes on their backs — rather than their mouths, allowing them to almost bury themselves in silt and sand.

From Washington Post

Certain species, such as nurse sharks, can do this by sucking water through their mouths or special openings on their heads known as spiracles.

From BBC