The balancers eventually fall off and their external gills grow larger.

They have small dark spots and are born with external gills.

Most were aquatic and external gills are sometimes found preserved.

They have a distinctive high tail fin and external gills.

Some amphibia are not fish, but live in water and have external gills.

It has persistent external gills and only the anterior pair of legs.

After about four months these external gills disappear and the lungs begin to work.

Burgess' thought came: 'The creatures with external gills do use them in air.

In most cases, these are external gills, visible as tufts on either side of the head.

Most other species, however, have external gills, generally, although not always, associated with the parapodia.