1 Invasive Marine Invertebrate

Scientific Name: Hemigrapsus sanguineus

Common Name: Asian Shore Crab

Location Found: Canoe Beach, Nahant MA; on shore in the intertidal and 10-15 feet deep in subtidal

Habitat Types: intertidal and subtidal around rocky substrate

Physical Description: 3 spines on each side of the carapace, purple/red/brown color with banded legs (https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=183; Pollock, L. W. (1998). A Practical Guide to the Marine Animals of Northeastern North America. New Brunswick, NJ: Rutgers University Press)

Fun Fact: Introduction unknown but speculated from ballast water discharge. First seen in MA in 1992 (https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=183)

Northern Moon Snail found in Nahant at Pumphouse Beach during a dive. It was fully emerged from its shell, crawling along the seafloor.

Moon Snails have very dull white and blue-gray shells with dark brown operculums. They are found along the entire Northeastern United States coastline along the benthos, where they hunt for clams and other bivalves.

Members of the moon snail family, Naticidae, have sinuses in their mantle cavities that allow them to inflate their foot and mantle with water, greatly expanding its volume to actually encompass part of the shell as seen in this picture. When they are disturbed they will expel this water quickly to shrink their bodies back inside their shells.

https://www.pugetsound.edu/academics/academic-resources/slater-museum/exhibits/marine-panel/moon-snail/

Common name: Common Sea Star, also known as Asterias vulgaris. Also called the Northern Sea Star.
Location found: Found on a dive about 15 ft down on an area densely packed with rocks on top of a sand bottom. Found on Pump House Beach in Nahant, MA.
Habitat types: A. vulgaris are found on rocky shores along the coasts of the Atlantic Ocean. (http://animaldiversity.org/accounts/Asterias_rubens/)
Physical description: The A. vulgaris (or A. rubens) was identified based on the white madriporite. One of its arms was about 3.5-4 cm in length. It's body had a orange/red coloration.
Fun fact: A. vulgaris are considered "the most common and familiar starfish in the north-east Atlantic region" of England and Ireland. (https://www.marlin.ac.uk/species/detail/1194)

2 Marine Invertebrate

Scientific Name: Homarus americanus

Common Name: American Lobster

Location Found: Canoe Beach, Nahant, MA; 10-15 feet in subtidal

Habitat Types: found in the rocky subtidal zone along the Atlantic coast of North America from Canada to New Jeresy

Physical Description: Crustacean; unique body compromised of 2 main body parts (head/body and tail), 2 large claws and 2 antennae. Usually dark green/brown/orange in color.(Martinez, A. J. (1994). Marine Life of the North Atlantic Canada to Cape May. Locust Valley, NY: Aqua Quest; Pollock, L. W. (1998). A Practical Guide to the Marine Animals of Northeastern North America. New Brunswick, NJ: Rutgers University Press)

Fun Fact: One of their claws can exert pressure of up to 100 pounds per square inch. (http://time.com/3184569/11-lobster-facts-that-will-leave-you-shell-shocked/)

Common Name: Flat or Yellow Periwinkle

Found during low tide on rocky shore in Nahant, MA searching through Ascophyllum nodosum

Habitat: Commonly found from Arctic to New Jersey on Fucus and Ascophyllum in the intertidal zone.

Physical Description: Small gastropod with low spire and 4 whorls with the last whorl being the largest. Color varies from brown, yellow, and orange to black or green. Can also have white or brown spiral bands on shell. Size is 1/2 inch.

Fun Fact: Lays egg masses directly on algae and those eggs take about 4 weeks for the young periwinkles to come crawling out!

Source: https://www.marlin.ac.uk/species/detail/1487

This species can be found from Canada all the way down the east coast to the Gulf of Mexico. It can hybridize with another type of mussel in the southern part of its range. The defining features of this species are the grooves that cover its shell.

Fun fact:
This species usually only reproduces one time per year but in Venezuela 2 reproductive cycles per year has been observed.

https://en.wikipedia.org/wiki/Geukensia_demissa

European Green crab, found in Nahant at Pumphouse Beach, 15 feet deep on a dive among algae encrusted rocks. Can vary in colors but usually are dark green like this one. Typically found in shallow estuarine and marine waters.

They are an invasive Species from Europe. Identified by the five marginal teeth along the outer carapace in between each eye and the legs.

Older individuals will sometimes change the color of their underside from green to orange and red. This seems to be an attractive color to mates and results in a thicker carapace as well, though results in a lack of environmental adaptability and tolerances with salinity and temperature changes.

https://www.marlin.ac.uk/species/detail/1497

Common name: Forbes' Sea Star
Location Found: This sea star was found at a depth of about 17 ft on a rocky/sandy ocean floor. It was found during a dive on Pump House Beach in Nahant, MA.
Habitat Types: Forbes' Sea Stars are found in waters from the Gulf of Maine to Texas. They typically live on rocks, gravel, or sand bottoms in the water or intertidal zone. (https://www.acaquarium.com/animals/forbes-sea-star/)
Physical description: This sea star was identified as a Forbes' Sea Star because of its orange madriporite. It was about 5 cm long and its body was pink/white/red in coloring.
Fun Fact: Sea stars can grow back limbs after a loss of one. They can sometimes overcompensate, however, and regenerate two limbs in place of one lost one. (https://www.acaquarium.com/animals/forbes-sea-star/)