[4] Ampullae grow shortly after the larvae settles in the sediments and are used to form a strong attachment to grains of sand.

[5] The grains of sand hold it down as the juvenile forms around seven to nine ampullae to create a secure attachment to soft sediments or hard substrates surrounding the organism.

[3] Their larvae are pelagic and they lack a tadpole stage because currents carrying them to shores where they settle in the intertidal or subtidal zone and form a temporary pseudopopulation.

This snail inserts its probuscus into a siphon found on the M. occidentalis and consumes the ascidian's internal organs, leaving the tunicate untouched.

[5] Because they are ascidians, they are part of the phylum chordata and have a notochord in the larval stage, but lose it when they metamorphose into adults.