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Ocean Watch Susan Scott |
Fleeting time with
frogfish fascinatesA few days ago, my friend and I found a live frogfish on a Windward beach. This was a near miracle to me. I can't find a frogfish on the reef when it's sitting right in front of my face.
I would have missed this one, too, if not for my little dog. She paused to sniff a brown blob on the shoreline, and soon I was not only seeing a frogfish, I was nursing one in a tank in my kitchen.
Frogfish are roundish creatures (fish books call them globose) that look like chunks of coral reef.
These unusual fish range in size from a few inches to more than a foot long, and blend with their background so well that even when pointed out, they can be nearly impossible to make out.
The frogfish we found was a little one, about 4 inches long, and lay on the beach like a gasping rock. It revived somewhat when I held it underwater, but its belly stuck out like a pufferfish. When I released the fish, it flipped bottom up and bobbed to the surface.
We filled a plastic bag with seawater and took the bloated fish home.
I bought a little rescue tank, filled it with seawater and introduced the frogfish to its hospital room.
The fish righted itself and swam to the bottom, but the air inside its body kept lifting it to the surface. Finally, the poor thing stayed there, breathing rhythmically but floating upside down.
To breathe, frogfish suck water into their mouths and push it out their armpits. Really. Frogfishes' pectoral fins look like little arms with jointed elbows, and at the base of each arm is a round gill-hole. By pushing water forcefully through these holes, the bulky, poor-swimming fish propel themselves around the reef.
Since my frogfish floated belly up, the water pulsing from its gills looked like two tiny fountains.
Like frogs, the well-camouflaged frogfishes (Hawaii hosts nine species) sit motionless on their arm-fins waiting for unlucky fish to swim by. But unlike their namesake, frogfish don't leave their meals to chance.
Above its mouth, each frogfish has a built-in fishing pole tipped with a fleshy lure. By flicking its pole, the frogfish attracts fish. When one draws near, the frogfish swallows it in six-1,000ths of a second.
And size doesn't matter. Frogfishes' mouth cavities can expand up to 12 times their normal size, and their stomachs can hold prey longer than the frogfish itself.
Frogfish have a suicidal inclination to swallow air if they exit the water. Saltwater aquarists know this and use water-filled containers to move their frogfish rather than nets.
And that's what turned my frogfish into a beach ball with fins. While lying on the beach, the fish filled its body with air.
Sometimes frogfish can expel trapped air on their own. Sometimes they can't. When that happens, they bobble on the surface until they die.
I propped a flat cheese grater in the corner of my fish ER, and the inflated creature wedged itself beneath it. Still, as much as my family and I wished it well, the fish died in the night.
I buried my frogfish at sea, and as I launched it, I thanked the ocean for laying this amazing creature at my feet. Not only did I get to know a frogfish personally, the experience reminded me of how lucky I am to live in Hawaii. Morning walks don't get better than that.
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Marine science writer Susan Scott can be reached at http://www.susanscott.net.