Aquatic (water-dwelling) invasive species are non-native plants, animals, and other organisms that have evolved to live primarily in water (aquatic habitats) rather than on land (terrestrial habitats). Aquatic habitats are habitats that are covered with water all or part of every year. From oceans to bogs, many types of aquatic habitats exist.
Aquatic invasive plants include algae, floating plants, submersed plants, and emergent plants. Aquatic invasive animals include insects, fish, reptiles, mollusks, crustaceans, and amphibians. Other aquatic invasive organisms include pathogens (disease-causing organisms), such as molds, fungi, bacteria, and viruses. (Source - eXtension: Aquatic (Water-Dwelling) Invasive Species)