Most crustaceans reproduce sexually but there are hermaphrodites and species that change sex with age.

An excerpt from the article 22 facts about crustacean

In crustaceans, internal fertilization occurs. Most aquatic crustaceans guard their eggs and carry them with them on their legs, in body cavities or nesting bags until they hatch, while others simply attach them to rocks or release the fertilized eggs into the watery depths.