Scuba Diving - New Jersey & Long Island New York

Scuba Diving - New Jersey & Long Island New York

Mollusks - Snails ( Gastropods )

Invertebrates

Whelk X-rayThese creatures are all of the order Gastropoda - having a single, often coiled, shell, as opposed to the bivalves, which have two matching shells. Most snails are hermaphroditic. Also, most snails have a right-hand twist to the shell, although there are exceptions.

Nudibranchs are a form of snail that has lost its shell, while Corollas and Sea Butterflies are snails that have abandoned not just their shells, but the snail-like existence entirely, swimming up into the water column as plankton.

Right:
X-ray image of a Channeled Whelk, showing internal structure.

Anatomy
Gastropod anatomy


 

Channeled Whelk

WhelkBusycon canaliculatum

Size: to 8"

Habitat: intertidal down to 60 ft

Notes:
Whelks are the largest snails in this area. Related Lightning Whelk grows to 16", and is sometimes called Conch and eaten as such. Whelks prey on bivalves by drilling through their shells.

(c) Rich Galiano
A large ( and filthy ) whelk feeding on something. The head end is to the left.

(c) Rich Galiano
Upended and fully withdrawn, showing the operculum which closes-off the shell. This
individual was about the size of your hand. Note the curious puffer fish at upper-right.

(c) Herb Segars
The somewhat smaller Waved Whelk Buccinum undatum is a scavenger

See Restrictions and Health Advisories for catch limits.


 

Northern Moon Snail

Moon SnailLunatia heros

Size: to 4"

Habitat: generally in deeper water, but possible in shallows

Notes: quite common in places

sand ringThese snails are responsible for the curious sand collars that divers often find. They produce a glue to cement the sand grains together into a protective ring for their eggs. Moon Snails are predators of other shellfish, which they smother with their enormous foot. They are themselves sometimes eaten as Scungilli.

(c) Herb Segars


 

Mud Dog Snail

Mud Dog SnailNassarius spp

Size: to 1"

Habitat: intertidal to shallows, on muddy bottoms

Notes:

This scavenger is often found on dead fish and other animals.

(c) Herb Segars
Feeding Mud Dog Snails swarm over an egg mass.


 

Oyster Drill

Oyster DrillUrosalpinx cinera

Size: to 1"

Habitat: subtidal down to 50 ft

Notes: This little snail uses acid and its rasp-like tongue to drill a neat hole in a bivalve or barnacle victim, then sucks out the contents.

(c) Herb Segars


 

Common Periwinkle

PeriwinkleLittorina littorea

Size: to 1.2"

Habitat: intertidal, on any solid substrate

Notes: vegetarian - feeds on seaweeds

This is another good snail for a cold-water aquarium, as it will constantly clean all surfaces of algae, and also consume any other waste it finds. They are also edible.

(c) Rich Galiano


 

Common Atlantic Slipper Shell ( Boat Shell )

Slipper ShellCrepidula fornicata

Size: to 0.8 - 2 "

Habitat: attached to solid surfaces, often other larger shells

Notes:

Although the dead empty shells superficially resemble bivalves, Slipper Shells are actually extremely flattened snails. The living animal has only a single uncoiled shell, and lives under it attached to a hard surface. A small shelf inside gives these odd animals their name. The illustration shows the shell from above on the left and from below on the right. Slipper shells are quite commonly attached to the undersides of Sea Scallops, often in stacks. Filter feeders.

(c) Herb Segars
Slipper shells hitching a ride on a scallop