National Geographic : 1956 Jun
+Stubby Baby Surgeons Lack the Sleekness of Their Elders Three larval stages of Acan thurus hepatus, magnified five times, carry long spines that will disappear at full growth. Heads and eyes are dispro portionately large. The baby surgeonfish spends its larval life among the plank ton. Later it undergoes an abrupt change, assuming the adult's appearance in minia ture within a few hours' time. Below: Adult surgeons swim in a tank at the Miami Sea quarium. Scalpel blades which open like jackknives on either side of the tail give the fish its name. These knife-edged spines are used for defense only. 866 Nights I would idle the engines and we would put the big net over the side. Half hour tows filled the big jar at the end of the 34-foot cone net with swarming planktonic animals (page 865). Between hauls we lay motionless on the quiet Gulf Stream with a light rigged over the side. Within minutes the waters would stir as darting copepods, fairy shrimp, tiny fish, and squids flashed back and forth, drawn by the bright rays. Plying long-handled dip nets, we would catch these fantastic fast-swimming creatures which usually evaded our tow nets.* Baby Sailfish in Dolphin's Stomach We even do some fishing ashore. Since fish larvae are eaten by nearly everything that swims, including their own parents, we often examine at the docks the stomachs of fish brought in by fishing boats. We have obtained baby fishes in perfect shape, like the three-inch sailfish complete with bill and sail we took from a dolphin, that swift pred- ator of the Gulf Stream's edge (page 862). Chicken heads tossed overboard from a ship, argonaut shells, even a set of false teeth have been found in fish stomachs. The teeth set off a row be tween two fishermen: each claimed ownership. Oddly enough, the teeth fitted both men equally well! Once we safely stow the plankton, the shore scientists take over. Many times my wife Nancy and I stand fretting, our eyes on some odd fish we are eager to examine, while Joan Clancey, third regular on our team, measures the plankton in a graduated flask to determine the concentration of floating life in the sea sector we are working. She also makes note of the salinity and temperature of the water from the records taken at sea. When Joan has finished, we pour the plank ton into shallow dishes and examine it under the microscope to sort out and record for fur ther study the tiny larval fishes and eggs (page 864). Sometimes we find weird and entertaining creatures: lantern fish with head lights to attract prey, hatchet fish flashing gold and silver sides and rows of light organs, viperfish armed with saberlike teeth. We smile when we spot an engraulid, whose hairy appearing muzzle and floppy, earlike fins * See "Night Life in the Gulf Stream," by Paul A. Zahl, NATIONAL GEOGRAPHIC MAGAZINE, March, 1954.