The tubercles on their test are perforated, and most species possess gills.

The larva possesses gills and does not leave the pond environment where it was hatched.

They are viviparous animals, giving birth to young that possess external gills.

Possessing both lungs and gills, she could breathe and exist indefinitely on land or under the sea.

All chordates possess a notochord and gills at some stage of their development.

It has been claimed that some forms possessed gills and gill slits.

Dwarf sirens possess external gills throughout adulthood and lack hind legs.

Unlike some other sea urchins, they also possess gills.

At this moment he is revealed to possess gills and webbed hands.

This larval stage also possesses tails and gills that are not quickly resorbed in comparison.