New Jersey Scuba Diving

Snails

x-ray

These 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.

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

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.

Gastropod anatomy
Gastropod anatomy

Channeled Whelk

Channeled Whelk

Busycon 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.

More: Channeled Whelk ...

Mud Dog Snail

Mud Dog Snail

Nassarius spp

Size: to 1"

Habitat: intertidal to shallows, on muddy bottoms

Notes:

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

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Oyster Drill

Oyster Drill

Urosalpinx 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.

More: Oyster Drill ...

Common Periwinkle

Periwinkle

Littorina 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.

More: Common Periwinkle ...

Slipper Shells

Slipper Shell

Crepidula 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.

More: Slipper Shells ...

Scallop Dredges

scallop dredge
Scallop

Scallop dredging is similar to clam dredging in that large metal rakes are dragged across the bottom. However, that is where the resemblance ends. Since scallops live on the surface, unlike buried clams, they can be harvested with much lighter-weight gear. A scallop rake is typically much smaller than a clam rake, consisting of a triangular frame with a chain-link catch-bag. No hydraulics are necessary. Such gear does not require as much towing power as for clamming. Since scallops are cleaned at sea as they are caught, and all the heavy shells discarded, there is also much less on-board storage requirement. Scallop boats can therefore be smaller than clam boats, and some are quite small indeed. In fact, the entire business model seems to be different, and it appears that a few small privately-owned operations persist to this day, in contrast to clamming, which is now dominated by a few corporate fleets.

More: Scallop Dredges ...

Disclaimer:

I make no claim as to the accuracy, validity, or appropriateness of any information found in this website. I will not be responsible for the consequences of any action that is based upon information found here. Scuba diving is an adventure sport, and as always, you alone are responsible for your own safety and well being.

Copyright © 1996-2024 Rich Galiano
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