- 1Any of a series of openings between the gill arches of a fish, through which water passes from the pharynx to the exterior, bathing the gills in the process.More example sentences
- One small gill slit is found in front of each pectoral fin.
- Water exits through the gill slits at the back of the head.
- Water is taken in through the spiracles, passed over the gills, and expelled through the gill slits on the underside of the body.
- 2A set of grooves similar to gill slits found in embryos of higher vertebrates.More example sentences
- This may be illustrated by the gill slits in the embryos of higher vertebrates like reptiles, birds and mammals.
- Thus, the gill slits of the early human embryo supposedly repeat our distant ancestral past as a fish, while the transient embryonic tail, developing just afterward, marks the later reptilian phase of our evolutionary ascent.
- Another myth is the claim human embryos go through a fish-like stage and display gill slits.