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Marine Invertebrates

Many species of invertebrates can be found swimming or crawling in New York's marine waters. Invertebrates are animals that do not contain a backbone. Many of the species harvested in NY waters contain a shell or a hard exoskeleton for protection. To grow, an individual will shed its outer shell multiple times during its lifetime, in a process called molting.

Learn about the most common marine invertebrates that can be found in New York's waters below:

American Lobster

american lobster
American lobster

(Homarus americanus)

Lobsters are found from Maine through North Carolina in offshore waters and from Maine to New Jersey in inshore waters. They prefer to live in rocky crevices or burrows. The Gulf of Maine/Georges Bank stock is above target population levels, while the Southern New England stock (the populations seen in our waters) is below target levels. The main diet of a lobster is crabs, mussels, clams, starfish, sea urchins and various marine worms. Lobsters eat mostly animals, but if these resources are scarce, as they are sometimes in the spring, a lobster might eat plants, or even sponges to survive. Lobsters can molt up to 25 times over a period of 5-8 years between the time they hatch and are able to reproduce. Lobsters usually mate after the female molts and the female can carry the males sperm internally for up to a year and the fertilized eggs for 9-11 months. Egg bearing females can be seen in inshore waters during late spring and early summer and they are illegal to harvest.

For information on harvesting lobsters, visit Lobster Permits.

Atlantic Horseshoe Crab

atlantic horseshoe crab
Atlantic horseshoe crab

(Limulus polyphemus)

Horseshoe crabs have been around for 380 million years and are considered a living fossil. The Atlantic horseshoe crab can be found from Maine to the Gulf of Mexico and can live up to 20 years. Although they are called crabs they are more closely related to spiders and scorpions. Adults spawn at high tide around the full and new moon. Their eggs are a very important food source for shorebirds and fish. Adults are harvested for use as bait in the eel, conch, and killifish fisheries, as well as for their blood in the medical industry. Limulus amebocyte lysate (LAL) is a clotting agent in horseshoe crab blood which is used to detect human pathogens and is required by the FDA.

For information on recreational harvest of horseshoe crabs visit, Recreational Saltwater Fishing Regulations.

For commercial harvest information visit, Commercial Limits for Lobsters, Crabs, and Whelk.


whelk and egg cases
Whelk and egg cases

Whelk is a common name that applies to many species of large predatory sea snails. Two species that are commonly found in our waters are channeled (Busycon canaliculatum) and knobbed whelk (Busycon carica). Both species can be found from Massachusetts to Florida and prefer sandy substrate and are located in the intertidal and subtidal zones. Channeled whelk prefer shallow waters, where knobbed whelk alternate between deep and shallow waters depending on the season. These two species are easy to tell apart, the channeled whelk has channels going along its body whorl whereas the knobbed whelk has a series of knobs along its body whorl. Both shells are considered right handed, which means if you hold the shell with the opening facing the viewer, the opening will be on the animal's right side. These marine snails are predators, preying upon clams by hammering away at their shells and consuming the soft part of their bodies. Both species are increasingly becoming and important fishery in our local waters.

Crab Species

For information on recreationally harvesting crabs, visit Crabbing in New York.

Blue Crab

blue crab
Blue crab

(Callinectes sapidus)

Blue crabs are named after their bright blue claws. Their scientific name means "beautiful savory swimmer". They can be found in estuaries from Nova Scotia to South America. Blue crabs play a vital role in the marine ecosystem as predators, regulators, and consumers in benthic, seagrass, and saltmarsh communities; and as a prey species they act as a food source to a wide diversity of ecologically and economically valuable organisms.

Males mate several times throughout their lifetime, where females only mate once during their terminal molt into maturity. Mature females migrate to the mouth of the estuary where eggs are spawned and carried to the ocean by tides. During the fall months, newly hatched blue crabs utilize the tides to make their way back into the estuaries where they will grow.

Blue crabs are one of the most harvested creatures on the planet and provide important commercial and recreational fisheries along the Atlantic coast of the United States. For information on the commercial blue crab fishery, visit Commercial Limits for Lobsters, Crabs & Whelk.

Jonah Crab

(Cancer borealis)

jonah crab
Jonah crab

Jonah crab are found from Newfoundland to Florida. They move offshore in the fall and the winter, with females moving back inshore in the late spring and summer. Jonah crabs can be distinguished from other cancer crabs by their robust claws with dark brown tips. They eat mussels, arthropods, snails, and polychaetes. In the past, Jonah crabs were mostly considered bycatch from the lobster fishery, but recently are becoming an increasingly important fishery.

To learn more about Jonah crabs, visit Atlantic States Marine Fisheries Commission's website (link leaves DEC website).

Atlantic Rock Crab

(Cancer irroratus)

rock crab
Rock crab

Rock crabs can be found from Labrador to South Carolina. They are similar in appearance to Jonah Crab. Rock crabs can be distinguished by their brownish spots on their carapace and by the smooth edges to their teeth along the edge of the carapace. They are scavengers that feed on algae, mussels, arthropods, snails, and polychaetes. Rock crabs were once considered a nuisance in the lobster fishery because they would steal the bait from the lobster traps, but now are a popular fishery themselves.

Atlantic Spider Crab

(Libinia emarginata)

Spider crabs can be found from Nova Scotia to Florida. Spider crabs are a non-threatening species that can be found living in all types of substrate, but are most commonly found in shallow bays and estuaries. They are very tolerant of polluted environments or areas with low oxygen. Spider crabs are scavengers that mostly feed on detritus and algae. They defend themselves by camouflaging themselves with debris and algae, and due to this behavior are also called decorator crabs.

Lady Crab

(Ovalipes ocellatus)

Lady crabs are named due to their brightly colored yellow and purplish leopard pattern on their carapace. Lady crabs are found from Canada to Georgia. They are aggressive crabs that live in shallow waters throughout bays. Lady crabs feed mostly on molluscs, but also eat both dead and live fish, crabs, and other invertebrates. Their meat is not considered as tasty as other crab meat, so they are not harvested commercially.