What Is Spiracle in Fish?

The spiracle is a small hole behind each eye that opens to the mouth in some fish. In the primitive jawless fish, the first gill opening immediately behind the mouth is essentially similar to the other gill opening. ... Blowholes in cetaceans are also sometimes referred to as spiracles.

What does a spiracle do?

Structure of the spiracle

Insects have spiracles on their exoskeletons to allow air to enter the trachea. In insects, the tracheal tubes primarily deliver oxygen directly into the insects' tissues. The spiracles can be opened and closed in an efficient manner to reduce water loss.

What's the function of the spiracle in sharks?

Many sharks, especially bottom-dwelling species, have paired openings called spiracles located between the eye and the gill slits. Spiracles are used to take in water and ventilate the gills, even while the shark may be feeding or at rest on the bottom.