Spiracles are small openings on the surface of some animals that usually lead to respiratory systems. In elasmobranchs (sharks and rays), a spiracle is found behind each eye, and is often used to pump water through the gills while the animal is at rest (Fouts, 2003). A spiracle is also found in primitive bony fishes as the chirrups. Spiracles in insects Insects and some more advanced spiders have spiracles on their exoskeletons to allow air to enter the trachea (Solomon et al., 2002). However, t… (More on Spiracles)