What are spiracles ?
1 Answer
Spiracles are openings on the surface of some animals, which usually lead to respiratory systems.
Explanation:
Insects have spiracles on their exoskeletons to allow air to enter the trachea. These spiracles are located laterally along the thorax and abdomen of most insects - usually one pair of spiracles per body segment. Airflow is regulated by small muscles that operate one or two flap like valves within each spiracle - contracting to close the spiracle, or relaxing to open it.
The timing and duration of spiracle closures can affect the respiratory rates of the organism. Spiracles may also be surrounded by hair to minimise bulk air movement around the opening, and thus minimise water loss.
In some fish spiracles exist as a small opening behind each eye that leads to the mouth.
