Category: Fishes

Bluehead Wrasses – The Great Damselfish Egg-Raid

Fishes, HIGHLIGHTS, Poseidon Media, Who's Who - Fishes

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

Read more

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

Bony Fish Basics, Fishes, HIGHLIGHTS

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

Fish Hunting Parties

Bony Fish Basics, Fishes, HIGHLIGHTS

ANIMALS IN THE OCEAN ARE ALWAYS LOOKING FOR FOOD (and trying to avoid being food). Some times it involves more than one animal. On Bonaire, one year, I encountered several instances of group fish hunting. Sort of. There’s a known phenomenon called Nuclear Hunting in which a small eel (like a goldentail moray) and one or more other fishes (like rock hinds) meet up, identify a nearby coral head as a target site and race toward

Read more

Parrotfish Beaks Are Really, Really Strong

Fishes

CORAL REEFS ARE DYNAMIC EQUATIONS, CONSTANTLY BEING BUILT UP AND TORN DOWN. The stony corals and the coralline algae mostly do the building. Major factors in the tearing-down side are parrotfish. And, especially, the teeth in parrotfish beaks. Parrotfish don’t set out to tear down coral. As herbivores, they focus on eating the algae that live on the surfaces of coral polyps’ calcium carbonate exoskeletons, or corallites. And they work at this pretty continuously, scraping

Read more

Reef Lizardfish, Ambush Experts

Fishes, The Photo, Who's Who - Fishes

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

Read more

Lionfish Hunting Techniques Count on Confusion

Fishes, HIGHLIGHTS

INVASIVE LIONFISH HAVE BEEN A PROBLEM FOR NATIVE FISH SPECIES throughout  the Atlantic/Caribbean since their introduction into Florida waters in the 1980s. For one thing, they have the advantage of preying on fishes unaccustomed to their modus operandi. For another, lionfish hunting techniques are fast, crafty and sneaky. In the Indo/Pacific basin, they’re formidable predators anyway, equipped with a wealth of venomous spines, superb camouflage in colorings and body shape and an ability to herd

Read more

Pearlfish and their Sea Cucumber B&B

Awesome Video, Echinoderms, Fishes, HIGHLIGHTS, Invertebrates, Who's Who - Fishes

A POST HERE SEVERAL MONTHS AGO closed with the “Really Odd Fact” that blenny-like pearlfish (Periclimenes imperator) have a habit of taking up residence in the … well…rear ends of sea cucumbers. The overall post, “Sea Cucumbers – Superheroes of the Sea,” was about the fact that sea cucumbers, often ignored as inert, unimportant creatures, actually had a lot to recommend them.  THE PEARLFISH/CUCUMBER EQUATION The pearlfish/cuke interaction is generally described as commensal relationship, but that term implies a

Read more

“Fish Flashing:” Fishy Therapy, or Simply a Good Backscratch?

Bony Fish Basics, Fishes, The Photo

WHETHER FOR HEALTH OR PLEASURE, FISH SOMETIMES ENGAGE IN A PHENOMENON CALLED “FLASHING,” otherwise known as rubbingtheir bodies along the sea bottom. Ned Deloach, in his estimable Reef Fish Behavior, describes it as an effort to deal with the irritation of parasites by scrapping them off, an alternative to the much more commonly seen symbiotic cleaning by small fishes and crustaceans. Discussions about the cleaning dynamic sometimes suggest that, in addition to health benefits, the fish

Read more

Who’s Who: Juvenile Slender Filefish

The Photo, Who's Who - Fishes

SLENDER FILEFISH (Monacanthus tuckeri) are only a few inches long and spend much of their time hiding out among gorgonians like this sea rod at the Turneffe Flats atoll off the coast of Belize.  They’re very good at camouflage and somewhat challenging to spot. They’re denizens of the Atlantic/Caribbean basin, found from the southeastern Caribbean as far north as North Carolina and Bermuda. SECOND OPINION PRINCIPAL SOURCES: Reef Fish Identification Florida, Caribbean, Bahamas; Reef Coral Identification, Florida, Caribbean, Bahamas,  Paul

Read more

Puffers Sleeping, Brittlestars at Work

Echinoderms, Who's Who - Critters, Who's Who - Fishes

THE MARKINGS OF THE FISHES AT LEFT AND LOWER RIGHT suggest members of the genus Canthigaster, sharp-nosed puffers often known as toby’s that are found in the Indo-Pacific. But the specific designs and colors are sufficiently different from the familiar black saddled toby (Canthigaster valentini) to suggest they’re not described in any of the references I have access to. CANTHIGASTER POSEIDONSWEBUS   But there are a lot of fishes in the sea, so to speak, and

Read more