Barnacles at Work

BARNACLES HAVE BEEN DESCRIBED AS SHRIMP THAT STAND ON THEIR HEADS AND FLYFISH WITH THEIR FEET. Despite the hard mollusk-like shells they build, acorn and gooseneck barnacles are crustaceans, related to shrimps, crabs and lobsters. Look closely and you’ll see fine, feathery extensions constantly being flicked into the current from within those shells, like expert fishermen casting and recasting into a stream. The creatures within use these “cirri” – adapted leg-like appendages – to capture

Advertisements
Read more

Shades of Orange – Clownfish, By the Numbers

1  ALL CLOWNFISHES ARE ANEMONEFISHES, but only two species of anemonefishes get to be called clownfishes, and one of them is the false clownfish (Amphiprion ocellaris). 2   Widely thought of as the archetypal clownfish, the adorable hero of Finding Nemo is actually a false clownfish, with three broad white bands encircling his body. But that’s a design that’s easily animated and he had great marketing reps. 3   The color patterns of true clown anemonefishes (Amphiprion percula) are

Read more

Nudibranch Colors: Awesome 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

Read more

 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

Read more

 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

Read more

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

Read more

 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

Read more

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

Read more

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,

Read more

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

Read more