It is certain that the mouth indirectly communicates with the spouting canal; but it cannot be proved that this is for the purpose of discharging water through the spiracle.
If it did breathe through open spiracles, these would be a weak point in the exoskeleton, where material inside could burst out from the pressure difference.
Insects breathe through a network of tiny tubes called tracheae, which extend throughout their bodies and open to the outside world through small holes called spiracles.
Oxygen enters these spiracles and diffuses directly into the tracheal system, delivering oxygen to cells and tissues, bypassing the need for a circulatory system to transport oxygen.
On every side the seven gables pointed sharply towards the sky, and presented the aspect of a whole sisterhood of edifices, breathing through the spiracles of one great chimney.
Nurse sharks even nap on the seafloor; however, they use a form of ram ventilation in which they draw in water through nostril-like structures near the eyes, called spiracles, and force it out through the gills.
You would almost think a great gun had been discharged; and if you noticed the light wreath of vapor from the spiracle at his other extremity, you would think that that was the smoke from the touch-hole.