Take an afternoon of snorkeling, and you're sure to see plenty of the fish with thorns in their sides: the fishes of the family Acanthuridae, which include the surgeonfish, unicornfish and tangs. In a rough translation from the Greek, Acanthuridae means "thorn tail," and sure enough, the surgeonfish carry two "scalpels" on either side of the body near the tail. Normally, these blades are tucked in, lying flat against the body, but can be sprung open like a switch-blade when needed for defense or for muscling out intruders from their feeding areas. Many surgeonfish have brightly colored patches around the spines just to drive the point home, so to speak. Unicornfish have similar structures, though they have two pair, and theirs are fixed and bony. Surgeons typically have a flattened body, little puckered mouths and eyes that are found high on the head, giving them a somewhat innocent look for ones packing a concealed weapon. Many are herbivores, which brings them into the shallow, well-lit waters, where algae is abundant. Others are on clean-up patrol, snarfing up detritus (small bits of non-living organic matter) from sandy areas. By the way, the terms surgeonfish and tang are often used interchangeably, though some will reserve the term tang for fish in the genus Zebrasoma, such as yellow tangs. "Tangs" have "scalpels" as well. That might help explain why sometimes you will see Achilles tang referred to as the Achilles surgeonfish. The manini, or convict tang is the only endemic species of the twenty-five species of surgeonfish in Hawaiian waters. So there you have it, surgeonfish are some sharp-looking fish.
welcomes you to visit with the all the wonderful flora and fauna that we share this lovely aina with.