Diving with Manta Rays: Atlantic Giant Manta Encounter

DIVING WITH MANTA RAYS WAS SORT OF A DISTANT FANTASY. I just wanted to see them. The giant Atlantic mantas I had seen in the past were fast-moving and, mouths agape, totally focused on sweeping up the plankton they make their livings on. Suddenly here, there, gone. Spending extended time in close-up choreography with one of these gentle giants was not in my vision. Until it was. The dive was at Flower Garden Banks National

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 Fish Buoyancy – How Our Finny Friends Stay Neutral (Unless They Don’t)

ONE THING IS CLEAR – FISH HAVE BETTER BUOYANCY THAN YOU.  And, they don’t have to press any buttons. Many bony fishes have built-in versions of the buoyancy-compensators that divers use to control their position in the water versus changing ambient pressures. In these fishes’ case, it’s an internal gas-filled sac called a swim bladder that automatically works to counteract the ambient pressures applied by the waters surrounding it and keep the fish at neutral

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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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 Nematocysts & the Science of Sting

NEMATOCYSTS ARE OCEAN STINGERS’ SECRET WEAPONS. In fact, they are the stingers. The way in which nematocysts sting is a story of the sneaky, harpoon-like ordnance of Phylum Cnidaria – jellyfish, coral and gorgonian polyps, sea anemones, fire corals and hydroids. If you happen to touch a sea anemone, a sea plume or coral tentacles (which you shouldn’t do), you’re likely to not feel their sting. Actually, you’ve probably been stung, ineffectively. Those animals’ stingers

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How Sharks Smell Blood – Superbly, But Not Miles Away

HOW SHARKS SMELL BLOOD IS FAR MORE INTERESTING than their mythical ability to detect the scent of “a drop of blood miles away.” Scientists disproved that legend long ago, although you may still find it in cheesy movies and on shark-week type reality shows. Sharks do have an amazing sense of smell, but their long-range detection capabilities are limited to several hundred yards rather than miles, many authoritative sources suggest. And one study suggests that

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To Define Plankton, Think: “Ocean Food Bank”

THE PLANKTON IS ONE OF THE KEYSTONES OF THE OCEAN FOOD CHAIN. In fact, it’s one of the most important elements of life in the sea. And, yet, every time I mention the word, seek to talk about plankton, discuss plankton, define plankton, I can hear eyes roll all across Planet Earth. True, plankton doesn’t have the same excitement attached to it as, say, a celebrity punching a shark on You-Know-What Week. On the other hand,

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Conch Eyes & Zen

FOR MANY OF US, DIVING IS ZEN, A MEDITATIVE EXPERIENCE. For me, communing with our fellow travelers under the sea is a major part of it. Spending time on the sandy bottom contemplating a queen conch while its (somewhat eerie) conch eyes contemplate me is a part of that. Some places are better for conch fellowship than others. I’ve found friendly conchs at Little Cayman, Roatan and in the Bahamas (this queen conch specimen was

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Geohistory and the Triangle of Diversity

Gone diving. Out of touch. Not posting too much new stuff. In the meantime, here’s a re-post that’s terrific:  CONSIDER THE TRIANGLE OF DIVERSITY. It wasn’t that long ago (in geohistory terms) that tropical marine life was distributed much more uniformly worldwide than is the case today. The Earth’s landmasses were configured differently and a strong current circled the planet along the Equator, widely dispersing tropical life. So why, today, do many of us have to

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Sea Pearl Algae – A Species Spotlight

IF IT LOOKS LIKE A RUBBER BALL AND IT FEELS LIKE A RUBBER BALL, IT MUST BE…ALGAE, a version commonly called a sea pearl (Ventricaria ventricosa). Sea pearl algae is an occasional reef denizen found worldwide that stands out because it so often looks like a delicate glass ball. Typically about the size of a golf ball, sea pearls are remarkable for their structure. Each one is a single cell, all by itself. Its round,

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Reef Lizardfish, Ambush Experts

LIKE ALL LIZARDFISH, REEF LIZARDFISH ARE AMBUSH EXPERTS. With their typical lizard-ish posture of sitting up on their pectoral fins, their M.O. is to lie on the bottom and grab passing prey in the form of small (sometimes surprisingly large) fishes with lightning-fast strikes. Reef lizardfish (Synodus veriegatus) are Indo-Pacific denizens, one of some 45 species found worldwide in Family Synodontidae. LYING IN WAIT With colors and markings that help camouflage them, lizardfish are found on

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