Gills are used in the exchange of oxygen and [[1]] in the respiration of molluscs.

Gills are used in the respiration of molluscs such as snails, clams, and squids to exchange oxygen and carbon dioxide.

Molluscs are aquatic animals that rely on oxygen to fuel their metabolic processes. They use gills to extract oxygen from the water and expel carbon dioxide. 

The gills are found in the mollusc's mantle cavity and are made up of thin, highly vascularized filaments covered with many small, feather-like projections called lamellae. 

The gills' large surface area allows for a large area for gas exchange between water and blood.

Water diffuses oxygen into the bloodstream and carbon dioxide into the water as it flows over the gills.