[6] On its posterior end is a haptor, a specialized organ for attaching to the host fish, which has sixteen hooks around its edge.

[7] The parasites give birth to live young nearly as big as themselves and at this time, a further generation is already growing inside the neonates.

It everts its pharynx through the mouth and releases a digestive solution with proteolytic enzymes which dissolves the salmon skin.

[4] G. salaris was first described in 1952,[8] after being removed from a Baltic strain[2] of Atlantic salmon kept at the Hölle Laboratory in Sweden, near to the river Indalsälv.

A newer method of treatment employs dosing small volumes of aqueous aluminium and sulfuric acid into the river.