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Scientific name: Tritia trivittata

Common name: Threeline mud snail

Location: Long beach, Nahant, MA

Distinguishing feature: brown to light yellow shell;pindle shape of the shell with the lines and ribs that result in a bead-like shell texture (Duane Sept, J. 2008. A photographic Guide to Seashore Life in the North Atlantic Canada to Cape Cod. Princeton Univerisity Press: New Jersey)

This crab was found crawling on a piece of red algae off of Canoe Beach in Nahant. The organism is generally found in a variety of habitats from Nova scotia to Gulf of Mexico. They are generally a reddish, brown color and an oval shape with nine spines down the midline of the upper surface. Often these crabs are covered in debris and small invertebrates. A fun fact is that males have walking legs that are twice as long as the females. (Marine Life of the North Atlantic, Andrew J. Martinez)

Also shown: Pilayella littoralis

Common Name: Red Puff Balls

Location: Found dead washed onshore at Long Beach, Nahant, MA.

Habitat: Intertidal to subtidal, can be attached to rocks, other algae, or found free floating.

Physical Description: Small, red, puffs. Can be about an inch and a half in diameter.

Fun Fact: While it may smell bad after washing up on the beach in large amounts, it is not harmful like "Red Tide" algae.

Stewart Van Patten, Margaret. Seaweeds of Long Island Sound. (Connecticut: Connecticut Sea Grant College Program, 2009) 95.

Common Name: Shotgun Kelp

Location: Found dead washed onshore at Canoe Beach, Nahant, MA.

Habitat: Shallow sublittoral zone, reaches depths of 160 ft.

Physical Description: Olive green in color when alive, with many small holes on the leaf blade.

http://www.marinespecies.org/aphia.php?p=taxdetails&id=157207#notes

Fun Fact: Found in both the Northwest Atlantic and the Northeast Pacific.

https://www.sealifebase.ca/summary/Agarum-clathratum.html

Common Name: Red Crust
Location Found: found while scuba diving, was found on ocean floor with other shells - found alive
Habitat Types: can be found on rocks, shells, and algae - ranging from inter-tidal to shallow waters
Physical Description: colony height about 0.8mm and widths 76mm
Fun Fact: Red Crust is a common species found in ship and dock fouling communities!
Source: 'Marine Life of the North Atlantic' Andrew J. Martinez 2010
National Exotic Marine & Estuarine Species Information System - Fofonoff PW 2018

Mercenaria mercenaria, commonly known as the hard-shell clam or northern quahog, is native to the eastern shores of North and Central America. It is typically found in the sand or mud habitats of shallow water. This organism was found in an intertidal mudflat at low tide. This species is distinguished by its thick oval shell. It can reach lengths of up to 127 mm and widths of up to 108 mm. It is dull grey in color with concentric growth lines across its length. A fun fact about this species is that its genus name, mercenaria, comes from the fact that Native Americans used pieces of its purple-edged shell for wampum.

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/Hard_clam

Pachycerianthus borealis, commonly known as the northern cerianthid, is found along the Atlantic coast of North America in sandy/muddy habitats from 6 to 488 m in depth. This organism was found while scuba diving at around 20 ft. This species can be distinguished by two whorls of tentacles around its mouth, the inner whorls being shorter than the outer whorls. It can grow up to 46 cm in height and 38 mm in width. The body of this species is typically colored brown and its oral disk is a pale yellow brown, getting darker towards the mouth. A fun fact about this species is that it lacks a pedal disk meaning it doesn't adhere to rocks but buries itself in sand or mud instead.

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

Scientific name: Tritia trivittata

Common name: Threeline mud snail

Location: Long beach, Nahant, MA

Distinguishing feature: brown to light yellow shell;pindle shape of the shell with the lines and ribs that result in a bead-like shell texture (Duane Sept, J. 2008. A photographic Guide to Seashore Life in the North Atlantic Canada to Cape Cod. Princeton Univerisity Press: New Jersey)

Common Name: Common Slipper Snail

Found attached to a crustous algae covered rock on a dive about 20 ft. deep off of Pumphouse Beach in Nahant, MA. Found during the month of October.

Habitat: Generally, common slipper snails are found attached to solid objects including rocks and shells from Canada to Texas.

Physical Description: Convex shell with apex turned to the side. Interior shelf (not pictured) extends half the length of the shell. Exterior is whitish with brown markings. Usually less than 1 in. long.

Fun Fact: Accumulation of dead shells often dredged up and sold to oysterpeople so that they can pour them onto the seafloor to be used as substrate for oyster larvae to settle on.

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

Didemnum vexillum

Description: this one found in small small colonies on hard rock substrate is actually an invasive species
Found: On the hard substrate
Fun Fact: The earliest Tunicates were found during the Cambrian period

Common Names: Common Slippersnail
Location Found: found on the beach at low tide, dead, among other shells washed up at high tide
Habitat Types: intertidally to 12 m on hard substrate
Physical Description: shape of this species depends on the object that it is attached to, some shells are on the flat side, interior shelf extends up to half the length of the shell, white with brown markings, can grow up to 37 mm
Fun Fact: When this species is "stacked up" the bottom shell if female!
Source: 'Marine Life of the North Atlantic' - Andrew J. Martinez