Basic information about invertebrates on the reef

Nudibranch Facts, by the Numbers

THERE ARE TWO KINDS OF DIVERS: THOSE WHO ARE BONKERS ABOUT NUDIBRANCHS and those who ought to be. For those in the second category, here are some nudibranch facts. First, as the name “nudibranch” suggests – it’s from the Greek for “naked gills” – nudibranchs absorb their oxygen from the water through external breathing structures located on their backs. There’s great variation in gill architecture among the many species of nudibranchs, from flamboyant to demure. And

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Nudibranch Colors Shout Out Nudibranch Defenses

WITH FLAMBOYANT SWAGGER, NUDIBRANCH COLORS CALL ATTENTION TO THEIR SLUGY TORSOS – and that’s the point. As beautiful as they are, nudibranchs’ bright markings are statements telling potential predators to leave them alone. In brief, nudibranch tissues tend to be foul-tasting, if not toxic. Nudibranch’s colors are warning signs to potential predators that they’ll regret attempts to dine out on their nudibranchy flesh. There are other nudibranch defenses in the mix, as well. Some have

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The Difference Between Jellyfish and Comb Jellies

WHAT’S THE DIFFERENCE BETWEEN JELLYFISH AND COMB JELLIES?  They both come in blobby shapes and gelatinous, transparent bodies. But comb jellies – ctenophores – are entirely different from their oceanic jellyfish neighbors. Most importantly: They don’t sting. And some of them put on fantastic light shows. Note that I said “neighbors,” not “cousins.” The difference between jellyfish and comb jellies runs far deeper than the absence of stinging.  Recent research suggests that combs evolved with

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Flying Scallops – An Awesome Video!

UNLIKE OTHER MEMBERS OF THE BIVALVE FAMILY, SCALLOPS CAN FLY. And flying scallops make for an amazing sight! Well, actually scallops swim, by jetting along underwater, as shown in this awesome video from East Coast Divers, my old dive shop in Brookline, Mass. NEITHER A BURROWER NOR AN ATTACHER BE Like other bivalves – clams, oysters and mussels – scallops share the basic anatomical structures of other members of Phylum Mollusca. As members of Family

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Sea Cucumbers – Superheroes  of the Seas

TO MOST DIVERS, SEA CUCUMBERS WOULD SEEM LIKE THE INACTION FIGURES of the oceans. Mainly, they come off as inert, sausage-shaped lumps lying randomly on the sandy bottom and perhaps the least interesting obects on the reef. In fact, some of them have real Captain Echinoderm moves in them. For one thing, they’re nocturnal so what you see in the daytime isn’t what you’d get at night, when they creep around on their little tube

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The Moon Snail Sand Collar Mystery

FOR A LONG TIME, DURING MY NEW ENGLAND DIVING DAYS, the northern moon snail (Euspira heros) represented a mystery to me. I kept seeing these structures I knew were moon snail “sand collars,” mucus-bound masses of sand that were said be be egg-laden. Except that there didn’t appear to be any eggs. SANDY SAND COLLARS  MOON SNAIL SAND COLLAR MYSTERY SOLVED Then, one day, I found this: BIGFOOT SIGHTED! Thinking about moon snails brings to

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Horseshoe Crabs Need Some Love

HORSESHOE CRABS ARE “LIVING FOSSILS,” a group of animals that have been on Earth since before the dinosaurs. Beside being intriguing members of the web of life in their own right – they’re not actually crabs, but four species in a far different arthropod family – they immensely benefit us all. BLOOD WILL TELL   Their bluish, coppery blood is regularly harvested for a unique clotting agent that is used to test for bacterial contamination during the production

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Babies on Board: Lobster Reproduction Isn’t Easy

WHETHER WE CATCH THEM OR BUY THEM, the process of having a lobster for dinner begins with lobster reproduction – the tasty crustaceans begetting more of the same in the ocean. How lobsters reproduce is an arduous journey that takes as long as 20 months from mating to hatching. During much of that time a female lobster carries her eggs around on her underside, protecting and nourishing them. FIRST: MOLT YOUR SHELL AWAY    Like their

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Christmas Tree Worms: Beautiful (and Wormy)

EVERYBODY RAVES ABOUT THE BEAUTY OF CHRISTMAS TREE WORMS (Spirobranchus giganteus), with their fantastic arrays of bright colors and shapes like perfect fir trees. The wormy bodies behind the gorgeous finery, maybe not so much. The spiraling crowns we see are specialized tentacles, called radioles, that filter plankton from the  surrounding waters for food, passing it down to the worm’s mouth in cilia-lined grooves. They also work like “gills” to let the animals absorb oxygen.

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Six Ways in Which Algae is Our Friend

ALGAE COMES IN EIGHT GAZILLION DIFFERENT FORMS, from tiny little slimy green stuff to giant kelp, and to most of us it seems obnoxious and a thing to be ignored, if not despised. Except that algae is the foundation of the food chain, a pioneer in the evolution of life, and essential to our existence.  Algae uses sunlight to photosynthesize the carbon dioxide and hydrogen in water into the simple sugars that are nutrients for

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