There is a hole called a spiracle behind each eye.
Insects ‘breathe’ through a tracheal system, with external openings called spiracles and increasingly finely branched tubules that carry gases right to the metabolizing tissues.
The lantern nerves, which appear to be modified spiracular nerves, do not synapse directly on the photocytes, but rather in the tracheal system, which in insects delivers air directly to the tissues.
Catsharks have moderately large spiracles , or respiratory openings, and five pairs of gill slits.
Its spiracles located behind the eyes allow the guitarfish to remain under the sand for long periods of time and breathe easily by flushing clean water over the gills.
Two of these tissues, which can be readily dissected, are the anterior spiracular glands of third instar larvae and the male ejaculatory bulb.
The spiracular notch is deep and forms a well-defined break between skull table and cheek.
It has long been suggested that insects close the spiracles to prevent desiccation, minimizing water loss but exposing themselves to hypoxic stress.
It does seem to be associated with the spiracular groove; but such an ossification is also present in, for example, Cladistia.
In many cases, the transitional bones and the cheek are separated by a deep extension of the old spiracular slit, referred to in tetrapods as the ‘otic notch.’