Saturday, August 31, 2013

Walking With Sharks

Yes, there are walking sharks.  No, not like the Asian walking catfish, the foot-long "monster" that invaded Florida some decades back and could emerge briefly on land. (I lived in Florida then and was disappointed I never found one:I had to content myself with Zaat: The Walking Catfish, possibly the worst monster movie of the decade. In one unforgettable scene, the guy in the walking-catfish suit is wearing sneakers.)
The walking sharks (a.k.a. bamboo sharks or longtail  carpet sharks) are, from a movie monster point of view, even more disappointing.  They never top 65cm long and never emerge from the warm Southern Pacific waters. However, from a scientific point of view, they are very interesting indeed, and we've just found a new species.  (Took me a while to get there, I know.)
The shark Hemiscyllium halmahera isn't a flashy critter, being brown with darker camouflage banding, but you notice when it uses its oversized paired fins to crawl like a salamander along the bottom in search of sea cucumbers, small cephalopods, and whatever else it can grab.  We may be seeing a flashback to the ancient days when the first amphibious fishes, the rhipidistian crossopterygians (try saying that three times fast), presumably driven by evolutionary competition, increasingly adapted to shallow water... and some poked their snouts out of the water into the weird new environment we call "land."
And any time we find a new shark, it's cool anyway. Ask Paul Clerkin, graduate student, who found eight new species while accompanying a fishing vessel and sifting through the bycatch under the aegis of the Moss Landing Marine Laboratories Pacific Shark Research Center. Says Clerkin,  “Sharks haven’t really been explored as much as we think."

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