From crabs to octopuses, clams to marine worms, invertebrates play a significant role in ocean ecosystems. Many are important prey for fish, marine mammals, and humans. Others, such as corals and oysters, create essential habitat for marine species.
NOAA Fisheries is responsible for the sustainable management of many species of invertebrates—including white shrimp, Alaska snow crab, and Quahog clam—commonly harvested for human consumption. We are also responsible for protecting invertebrate species listed under the Endangered Species Act such as white abalone and elkhorn coral.
Invertebrates are the most diverse group of animals in the ocean. Some common marine invertebrates include mollusks, crustaceans, and corals.
Mollusks are a category of invertebrates with over 50,000 known species. They are soft-bodied animals that may have a hard external shell (formed by secreting calcium carbonate), a hard internal shell, or no shell at all. Mollusks include abalone, conch, oysters, and clams, as well as octopus and squid.
Crustaceans are a subcategory of invertebrates closely related to insects and spiders. They typically have a body covered with a hard shell or crust. Crustaceans include shrimp, krill, lobsters, and crabs.
Corals are known as colonial organisms because many individual creatures live and grow while connected to each other. The tiny, individual organisms that make up large coral colonies are called coral polyps. Stony, shallow-water corals—the kind that build reef habitat—are one type of coral. There are also soft corals and deep sea corals that live in dark, cold waters.
Species News
Juvenile coho salmon. Credit: iStock
Alexandrium catenella is the main species of algae that produces paralytic shellfish toxin in Southeast Alaska. Credit: University of Alaska Fairbanks/Courtney Hart.
Underwater photograph of a juvenile red king crab. Credit: NOAA Fisheries/Chris Long
A floating operations wharf with an oyster tumbler. Inside, workers remove barnacles from the oysters before they are graded and counted by an Oystek oyster grading machine. A solar-powered FLUPSY is attached to the wharf. During the 2024 Northeast Aquaculture Conference and Expo, Dale Leavitt, formerly of Roger Williams University, led a tour of Blue Stream Shellfish, which has been expanding in Fairhaven, Massachusetts. Credit: Lynn Fantom
Multimedia
Children fishing on a dock in Charleston, South Carolina. Credit: Jae Schmitz
Bering Sea snow crab support a valuable commercial fishery. Photo: NOAA Fisheries.
Research
Frequent Questions: Ruth D. Gates Coral Innovation Grants
Find answers to frequent questions about the FY2024 Ruth D. Gates Coral Restoration Innovation Grants
Scallop Vessels Transition to the Pre-Trip Notification System April 1, 2024
The Industry-Funded Scallop observer program vessel notification method will change at the start of the 2024 Atlantic sea scallop fishing year.
Sounds in the Ocean: Fish and Invertebrates
Listen to exemplar sound clips of marine sounds, taken from passive acoustic recorders. We have compiled these sounds to provide examples of the variety and breadth of fish and invertebrate sounds.
Understanding Sustainable Seafood
Well-managed wild-capture fisheries and environmentally responsible marine aquaculture play an increasingly important role in our food supply, our health, and the environment.
