Spiraculum (arthropoda)
Spiraculum sive stigma est apertura in exosceletis insectorum et nonnullarum aranearum per quam aer tracheam intrat.

In respiratorio insectorum systemate, tubi tracheales oxygenium recte in textum praecipue reddunt. Spiracula efficaciter aperiri claudique possunt ad aquam amissam imminuendam, musculis circa spiraculum contractis et remissis. Qui musculi a systemate nervoso centrali continentur, sed chemicis locorum stimulis libere respondent. Aliquot insecta aquatica rationibus similibus aut alternis utuntur ne aqua tracheam intret. Tempora et temporis spatia conclusionum spiraculorum respiratorias organismi proportiones afficere possunt. Spiracula a setis circumdata aeris motum circa aperturam et ergo aquae amissionem imminuunt vel prohibent.

Inveniuntur spiracula in omnibus insectis, sed solum in certis araneis, sicut araneidis et lycosidis. Omnibus araneis olim erant pulmones foliacei, non tracheae; aliquot autem araneae systema tracheale evolverunt praeter tracheale insectorum systema, quod etiam exemplum evolutionis convergentis est. Quae autem araneae eorum pulmones foliaceos retinent, ut ambobus rationibus spirandi utantur.

Bibliographia
Bailey, L. 1954. "The respiratory currents in the tracheal system of the adult honey-bee." Journal of Experimental Biology 31 (4), 589–93. PDF.
Beckel, W. E., et H. A. Schneiderman. 1957. "Insect spiracle as an independent effector." Science 126 (3269): 352–53.
Chapman, Reginald F. 1998. The Insects. Cantabrigiae: Cambridge University Press.
Lehmann, F. O. 2001. "Matching spiracle opening to metabolic need during flight in Drosophila. Science 294 (5548): 1926–29. Editio interretialis.
Schmitz, Anke. 2016. "Respiration in spiders (Araneae)." Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology 186, no. 4 (Maius): 403–415. . ISSN 1432-136X. PMID 26820263. S2cid 16863495.
Solomon, Eldra, Linda Berg, et Diana Martin. 2002. Biology. Brooks/Cole.
Swales, L. S., I. Cournil, et P. D. Evans. 1992. "The innervation of the closer muscle of the mesothoracic spiracle of the locust." Tissue and Cell 24 (4): 547–58. Editio interretialis.
Wilmer, Pat, Graham Stone, et Ian Johnston. 2005. Environmental Physiology of Animals.'' Oxoniae: Blackwell. ISBN 9781405107242. Editio interretialis.

Notae

Systema respiratorium
Anatomia arthropodorum