Tag Archive for ‘snails’ at Cephalopodcast

Close up of a small, brown tree snail [180x240, 24K]

Mangrove periwinkle (Littoraria angulifera)

I try to take a walk during lunch whenever possible. Sometimes it is just too dang hot, but today it was pleasant enough to make it down to the boardwalk. I came through at high tide and could not help but notice all the snails bunched up around the prop roots of the red mangroves. These were the coffee bean snails (Melampus sp.), and just as you might expect from the name, they are small, brown gastropods about the size of a bean. I watched what looked like a stone crab scuttle up one of the roots and dislodge a number of the snails. Then he dropped back down, presumably to be feast on the jetsam.

Higher up on one of the branches, almost at eye-level, was a mangrove periwinkle (Littoraria angulifera). I brought my iPhone with me and managed to get this marginal picture of it. I have a technique for getting macro shots with the crummy 2 megapixel camera which I will share with you in the near future.

I also learned today about the Life Photo meme via the Other 95% blog. Every Thursday the folks at Life Photo ask that one “post a photo of something that either lives, or is a product of life.” Eric Heupel contributed a post on the hard little crustaceans called ostracods (seed shrimp). I thought I would try this meme too and share my periwinkle picture from this afternoon.

I am starting another new feature here on the Cephaloblog, one that I hope will become a regular edition. I am calling it, What the Shell is That?

My inspiration comes from the weekly blog arcs of folks like PZ Myers (Friday Cephalopod), Peter and Craig (Friday Deep-Sea Picture), Rick MacPherson (Monday Moray) and Martin Brummell (Friday Fish), to name just a few.

The focus of What the Shell will be on things I find at the beach. Living on the southwest coast of Florida, that means mostly molluscs, especially bivalve (clam) and gastropod (snail) shells. But it could also be skate eggs, algae or nurdles. Anything in the intertidal is fair game, and not just dead things on the beach either.

Note, I am not a professional malacologist or a competent conchologist. Just a curious beachcomber looking to get outside more to search the surf and share with you. I am not interested in collecting live shells, just taking pictures and leaving only footprints/bubbles. I hope to post one entry each weekend, the day depending on when I can hit the beach.

Florida Horse Conch (Triplofusus gigantea)

The official state shell of Florida is neither a horse (obviously) nor a true conch (not so obviously) nor is it limited to just Florida. True conchs are in the family Strombidae, but horse conchs, along with the tulip shells, are in the spindle shell family Fasciolariidae. Up until recently this particular animal was known as Pleuroploca gigantea. I am still not certain what prompted the change in taxonomy.

I suspect it is called a horse conch because it is the largest snail in North America. These animals grow up to two feet long and are voracious predators of other marine snails.

The individual pictured above was a juvenile, approximately 3 inches long (7.5 cm) found half-way in the water on a piece of drift wood.

Some questions I am still seeking the answers to:

Why is the horse conch orange? How does it get this distinctive color.
As an adult, why does it have such a flakey periostracum?
Why is the horse conch so large?
Why the change from Pleuroploca to Triplofusus?

References

Additional Links

More photos: What The Shell
Whitney Laboratory of Marine Bioscience: Horse Conch (Pleuroploca gigantea)
Spindle Shells, Scallops, an excerpt from Florida’s Seashells by Blair & Dawn Witherington (pdf)

UPDATE: bobsonguam now informs me that Pleuroploca papillosa is being considered.

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