The Lionfish Enigma: Atlantic Threat But Not Pacific

LIONFISHES HAVE BEEN AROUND IN THE INDO/PACIFIC FOR EONS, yet almost all talk about them focuses on their presence in the Atlantic and Caribbean. Google “lionfish” and you’ll find a zillion articles on them as an invasive threat in the Atlantic basin for each one about them in their native habitat. Okay. That’s a bit of hyperbole, but the idea is good. There’s an enormous disparity in Atlantic and Pacific lionfish articles. Almost all of

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Osteichthyes vs. Chondrichthyes, Bony vs. Cartilaginous

The terms Osteichthyes and Chondrichthyes may seem a trifle wonkish, as opposed to street talk like “bony fish,” “sharks” and “rays,” but you will encounter them from time to time and should at least be aware of them. •   Osteichthyes (os-tee-ik’-thee-eez, from the Greek for “bone” and “fish”) is the taxonomic class of bony fishes, those with hard, rigid skeletons based on calcium, phosphate and other minerals, smooth scales, covered gills and flexible fins. With

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Trumpetfish: Sneaky, Relentless Predators on the Reef

THINK ABOUT THE MOST RELENTLESS HUNTERS ON THE REEF and you probably envision menacing sharks, barracudas and moray eels. But those are mere grandstanders in the predation game. High on the list of sneaky relentless predators would have to be a species of fishes that Caribbean divers encounter so frequently – and that appear so benign – that they’re likely to take them for granted and ignore them. After all, the ever-present trumpetfish (Aulostomus maculatus)

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Balloonfish & Porcupinefish: Big Eyes, Mona Lisa Smile

WHAT’S THE DIFFERENCE BETWEEN BALLOONFISH AND PORCUPINEFISH?  They’re both unobtrusive, usually little guys with an ability to inflate into spiny basketball-shapes when disturbed. It’s a defensive response to threats. And, divers are often confused as to which is which. First of all, when you see picture of them, they’re often inflated like stuffed pincushions. In fact, like this…. But the truth is that recreational divers who are minding their manners are unlikely to see them

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Hamlet Fishes: Chasing the Hamlet Grand Slam

WHO KNEW THAT SPOTTING LITTLE GUYS LIKE BUTTER AND BARRED HAMLET FISHES could be challenging? I’ve thought of them as fairly bland little fishes of modest interest. I’m aware of occasionally seeing vivid blue indigo hamlets (Hypoplectus indigo) in Bonaire and Belize but not the other dozen or so species to be found around the tropical Atlantic/Caribbean. Which sounds fishy considering that Humann and DeLoache’s Reef Fish Identification says barred hamlets (Hypoplectus puella) constitute the most

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Glass or Masked, Gobies We Hardly See You

THESE LITTLE GUYS ARE SO SMALL AND TRANSLUCENT THAT YOU HARDLY NOTICE THEM, but they’re actually pretty common on reefs in the Caribbean. Tiny fishes that swim in swarms of a dozen or so just off the corals, they’re either glass gobies or masked gobies. Both an inch or so in length, the two species are so similar that one source suggests the only way to be sure is to hold them in your hand

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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

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Bluehead Wrasses – The Great Damselfish Egg-Raid

IF YOU’VE DIVED IN THE TROPICAL ATLANTIC/CARIBBEAN, you’ve almost certainly seen bluehead wrasses. Of course, most of them weren’t blue. The blueheaded members of bluehead wrasse world are terminal-phase males, or supermales. Despite their high visibility, they make up no more than 10 percent of a given bluehead wrasse population. The overwhelming majority of bluehead wrasses are yellow – juveniles or initial-phase adults or something in between. Blueheads (Thalassoma bifasciatum) are among those fish that

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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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Bluehead Wrasses on an Egg Raid – An Awesome Video

AS A STUDENT OF LIFE UNDER THE SEA, I’m always curious about behaviors. So when, on a dive, I saw a pack of little yellow initial-phase bluehead wrasses streaking toward a distant point, naturally I followed them. They were almost certainly on an egg raid. Blueheads are notorious for plundering the egg nests of other species of fish, particularly damsels and blennies. BLUE HEADS & YELLOW BODIES To be clear, bluehead wrasses get their name from the

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