spiracle

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spi·ra·cle

(spī'ră-kĕl, spir-),
An aperture for breathing in arthropods and cetaceans; a similar opening in sharks and related fishes.
[L. spiraculum, fr. spiro, to breathe]

spiracle

(spĭr′ə-kəl, spī′rə-)
n.
1. Zoology A respiratory aperture, especially:
a. Any of several tracheal openings in the exoskeleton of an insect, spider, or other terrestrial arthropod.
b. A small respiratory opening behind the eye of most sharks and rays and certain other fishes.
c. The blowhole of a cetacean.
2. An aperture or opening through which air is admitted and expelled.

spi·rac′u·lar (spī-răk′yə-lər, spĭ-) adj.

spiracle

  1. (in fish) a gill-like cleft that opens behind the eye and through which water is drawn in for gaseous exchange (as it is through the mouth) by the expansion of the pharyngeal cavity. It is absent in many bony fish.
  2. (in arthropods) the exterior opening of the tracheae, often possessing valves that can close to prevent water loss.
References in periodicals archive ?
Posterior spiracles slightly protruding from caudal end.
Synergus filicornis: immature larva: General aspect (a), tegumental differentiation (b, under SEM), spiracle (c), and head (d) [antennal orbits (ao), maxillary (mp) and labial palpi (lp), sensillum (s)].
We think such incongruent results with character 7 could be circumvented by adopting a clear-cut proportion to define relative size of antenna, as was done by Kojima (1998) with character 35, relative size of first spiracle. Based on Figure 6 and analysis of Kojima (1998), we would tentatively suggest that the value of 0.067 [ratio between of antennal orbit /head width; this limit value was set from analyzing 27 species illustrations from Dias Filho (1975) and 116 species from Kojima (1998)] be adopted as the borderline to separate relative antennal size, with the result that some genera (e.g.
At this stage, the rays displayed tonic immobility, absence of tail and fin movements, absence of reaction to external touch and frequency of spiracle beats of less than 10 per minute.
The main key morphological characters for differentiation of the III larval stage in these three species of the subgenus Liopygia involve dorsal surface of the II thoracic segment, anterior spiracle digits/papillae, posterior spiracles, and the shape of the cephaloskeleton [3, 10].
Most puzzling were the unconcealed tympana of these species, combined with tiny auditory spiracles and other characteristics, each typical of a different subfamily.
Closer inspection of these lesions may reveal the two dark spiracles, or breathing holes, of the larvae, which are key to removing them, Dr.
They discovered that a gene in hornworm caterpillars allowed them to puff nicotine out through their spiracles (tiny holes in their sides), from the tobacco that they ate, Fox News reported.
Spiracle on A1 located ventrad and cephalad, whereas that of A2 is aligned with the remaining spiracles and located at center of segment in lateral view.