The fertilised eggs are retained in the mothers' gill chambers where they begin their development.

The time required to engorge itself with blood and leave the host's gill chamber ranges from 30-145 seconds.

From the second instar on, the larvae migrate to the gill chamber, where they stay up to several months.

When young are produced, they brood in the female's gill chamber.

When she locates one the worm enters the gill chamber.

Another important adaptation that helps breathing while out of the water are their enlarged gill chambers.

These large gill chambers close tightly when the fish is above water.

The gill chamber is also sometimes used by the commensal fish Careproctus to hold its eggs.

It enters and leaves the gill chamber during the host's ventilating movements.

The second instar is spent in the crab's gill chamber.