The statement contains a few inaccuracies. Crustaceans are actually invertebrates, not vertebrates. They belong to the class Crustacea within the phylum Arthropoda. This group includes animals like crabs, shrimp, krill, barnacles, crayfish, lobsters, and sea lice.
Furthermore, while many crustaceans are found in marine environments with high salt content, some species, such as crayfish, are commonly found in freshwater habitats. Additionally, some crustaceans can even tolerate brackish water, which is a mix of fresh and saltwater.
If you have more questions or need additional information about crustaceans or related topics, feel free to ask!