New Jersey Scuba Diving

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.

Snails

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.

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Lobstering - Know Your Foe

bug — This little guy will be safe from divers for a while. Notice how the tailings of his excavation are a different color than the surrounding bottom.

Lobsters, like most invertebrates, have a much slower nervous system than our own. In tiny creatures, such as insects, this is no great disadvantage, since their "wire runs" ( or nerves ) are so short. However, in bigger invertebrates, this translates into very long reaction times. Therefore, big lobsters have slow reflexes, much slower than even humans. Another common invertebrate trait is a lack of stamina, at least compared to us. In other words, they tire quickly in a chase. This is not to say that they lack tenacity - once they get a good grip on you, they can hold on forever, and even breaking the claw off may not cause it to release.

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