Location found: This dead Threeline Mudsnail was found on the berm of Long Beach, Nahant, MA.

Habitat types: Its range extends from the Gulf of St. Lawrence to Florida, and can be found on sandy or muddy bottoms intertidally to 90m.

Physical description: The shell of the Threeline Mudsnail is elongate and ovate with a high, conical spire and a convex body whorl. The aperture is ovate and notched at both ends; outer lip is thin, inner lip is strongly arched. Color is generally whitish to tan, but can darken to this observed brown color. Max size is 1.9cm.

Fun fact: Also known as the Basket Whelk and Dog Whelk, it is a scavenger and often found on dead fish.

Martinez, Andrew. Marine Life of the North Atlantic: Canada to Cape May. New York: Aqua Quest Publications, Inc. 1994.

The knotted wrack is found in quiet, rocky, intertidal water where there is minimal wave activity, as intense wave actions prevents this species from becoming established. It can be found from the Arctic to Long Island with its easily identifiable narrow, olive green to green black, ribless blades with air bladders. It has irregular branching with small, short branchlets.

Fun fact:
This algae is commercially valuable and is harvested and used for food emulsifiers and thickeners.

Source:
Marine Life of the North Atlantic by Andrew J Martinez 

Common Name: Atlantic Razor

Location: Found dead washed ashore on Long Beach, Nahant, MA.

Habitat: Shallow water and intertidal zones.

Physical Description: Color varies from shades of tan to brown. Length about 3 inches. Oblong.

Fun Fact: There's an identical looking species (Siliqua patula) on the Pacific coast!

http://www.marinespecies.org/aphia.php?p=taxdetails&id=159998#notes

Common name: Longwrist hermit crab
Location found: Tide pool (found alive)
Habitat: Tide pools, beaches, benthos. Littoral, sublittoral to 100 feet.
Physical Description: Carapace length up to 11 mm. Light brown to tan. Chelae(claws) are slender. Larger chela often has a dark longitudinal stripe. Often inhabit shells of Littorina spp.
Fun Fact: Shell-less individuals will often attack individuals with a shell, regardless of any size difference.

Sources: Weiss, Howard M. Marine Animals of Southern New England and New York. State Geological and Natural History Survey of Connecticut, 1995, p. 10.19.
Pollock, Leland W. A Practical Guide to the Marine Animals of Northeastern North America. Rutgers University Press, 1998, pp. 266-267.
Masterson, J. "Indian River Lagoon Species Inventory." Smithsonian Marine Station at Fort Pierce, Smithsonian Institute, 1 Sept. 2008, www.sms.si.edu/irlspec/pagurus_longicarpus.htm

Common name: Violet Tunicate
Species name: Botrylloides violaceus
Location found: Boothbay Harbor in East Boothbay, Maine
Status: Alive, attached onto rock
Habitats: Colonies attach and grow on solid substrates, and consist of individuals arranged in twisting rows. It grows on a variety of surfaces, include docks, boat hulls, buoys, ropes, pilings, undersides of rocks, eelgrass blades and algae.
Physical description: An area of tunicate attached to a substrate consit of dozens of zooids. Each zooid is a single color; all the zooids within a colony are the same color, ranging from orange, yellow, red, purple, or tan. However, the matrix is usually clear.
Fun fact: It is native to the northwest Pacific from southern China to Japan and Siberia. Outside its native range, it is considered an invasive species and are becoming more common in coastal waters of North America, most likely being spread by shipping industries
Reference(s):
https://en.wikipedia.org/wiki/Botrylloides_violaceus
http://www.exoticsguide.org/botrylloides_violaceus

Common Name: Moon Snail

Found while diving 20m in Nahant, MA on sandy bottom in September.

Habitat: From Gulf of St. Lawrence to N. Caroline on mud and sand in the intertidal to 366m deep.

Physical Description: This shell with 5 whorls and low spire. Foot is very large and gray. Shell color is gray to brown. Carnivorous snail and foot allows it to search through sand for other mollusks. Drills a hole through the shell with radula and digests contents.

Fun Fact: Eggs of the moon snail are preyed upon by green sea urchins.

Source: Marine Life of the North Atlantic Field Guide App - Martinez

The common sand dollar is found on sandy bottoms, from the low-tide line to 1 mile deep, from Labrador to Maryland. It is flat, circular, and has a thin test with a five-point petal like pattern of tiny holes on the upper surface. The mouth which is located on the ventral side has five branching grooves leading to it, with the anal opening at the edge of the test. They have a reddish purple and brownish coloring, and grow to a width of 79mm, and a height of 6mm.

Source:
Marine Life of the North Atlantic by Andrew J Martinez 

Fun fact:
With an exoskeleton made of calcium carbonate, you can count the growth rings to see how old it is.
https://www.softschools.com/facts/animals/sand_dollars_facts/1945/

Location found: This Northern (or Vulgaris) Sea Star was found on a large boulder in roughly 10m off Pump House Beach, Nahant, MA.

Habitat types: Its range extends from Labrador to Cape Hatteras, and it is more common north of Cape Cod than the Forbes' Sea Star. It can be found intertidally on rocky, sandy, and gravel bottoms up to 610m.

Physical description: The Northern Sea Star has five arms with prominent lines of spines on the upper sides of the arms; each arm has four rows of tube feet. Color can vary from red to brown, purple, or green, and max length is 30cm. Distinct white madreporite.

Fun fact: Sometimes the Northern Sea Star steals the prey of its relative, the Polar Sea Star.

Martinez, Andrew. Marine Life of the North Atlantic: Canada to Cape May. New York: Aqua Quest Publications, Inc. 1994.

https://www.mun.ca/osc/oscedu/avulgaris.php

Found diving at Pumphouse Beach in Nahant at a depth of around 10ft.

The common sea star are found intertidally on rocky, sandy, and gravel bottoms to 150' from Labrador to Cape Hatteras down to 2,000'. This sea star usually has 5 flattened arms that taper to a narrow tip and a large central disc. Often, there is a row of spines down the middle of the upper surface of the arm. The madreporite is a pale yellow, while the rest of the body can be found in shades of red, purple, orange, brown, and green.

Marine Life of the North Atlantic by Andrew J Martinez 

Fun Fact:
The common sea star is used for homeopathic remedies

http://www.waza.org/en/zoo/choose-a-species/invertebrates/star-fishes-sea-urchins-and-relatives-echinodermata/asterias-rubens

Common name: American lobster
Location found: Pump House Beach, Nahant, MA about 15 ft deep wandering the rocky ocean floor; found on a dive
Habitat types: Typically prefer rocky habitats, especially places where they can hide from predators (http://www.parl.ns.ca/lobster/overview.htm)
Physical description: This lobster was about a foot long. Most of its body was dark red, with some orange portions especially around the tail and claws.
Fun fact: Lobster used to be considered a poor man's meal, and used to be given to prisoners as meals. (http://time.com/3184569/11-lobster-facts-that-will-leave-you-shell-shocked/)

15 Marine Invertebrate

Scientific Name: Crepidula fornicata

Common Name: Common Slipper Snail

Location Found: Shell washed up along rocky beach of Little Harbor, Cohasset, MA

Habitat Types: intertidal to subtidal to 40 feet on hard substrate; Canada to Texas (Martinez, A. J. (1994). Marine Life of the North Atlantic Canada to Cape May. Locust Valley, NY: Aqua Quest)

Physical Description: rather flat shells (usually) but flatness depends on to what it is attached to; whitish shell with brown markings when alive; interior of shell extends up half the length of shell (Martinez, A. J. (1994). Marine Life of the North Atlantic Canada to Cape May. Locust Valley, NY: Aqua Quest)

Fun Fact: often found on the backs of horseshoe crabs! (Martinez, A. J. (1994). Marine Life of the North Atlantic Canada to Cape May. Locust Valley, NY: Aqua Quest)

Location found: This dead Threeline Mudsnail was found on the berm of Long Beach, Nahant, MA.

Habitat types: Its range extends from the Gulf of St. Lawrence to Florida, and can be found on sandy or muddy bottoms intertidally to 90m.

Physical description: The shell of the Threeline Mudsnail is elongate and ovate with a high, conical spire and a convex body whorl. The aperture is ovate and notched at both ends; outer lip is thin, inner lip is strongly arched. Color is generally whitish to tan, but can darken to this observed brown color. Max size is 1.9cm.

Fun fact: Also known as the Basket Whelk and Dog Whelk, it is a scavenger and often found on dead fish.

Martinez, Andrew. Marine Life of the North Atlantic: Canada to Cape May. New York: Aqua Quest Publications, Inc. 1994.

Littorina obtusata, common name flat periwinkle, is a marine gastropod found in the littoral and sublittoral zones of rocky shores, usually on brown algae. It is typically distributed in the Baltic Sea, European waters from Norway to southern Spain, the Mediterranean Sea, and the northwest Atlantic Ocean along the Gulf of Maine. This periwinkle was found on a rock located in the intertidal zone of Canoe Beach in Nahant, MA. It had a shell length of approximately 1/2", was yellow in color, and had a flat spire which is characteristic to flat periwinkles. Members of this species found on sheltered shores are typically lighter with a more uniform color, while those found on more exposed shores are darker and checkered.

References:
Martinez, Andrew. Marine Life of the North Atlantic: Canada to Cape May. New York: Aqua Quest Publications, Inc. 1994.

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