The Old Fish of the Sea

The Old Fish of the Sea

Josie Glausiusz

MARINE BIOLOGIST Mark Erdmann was strolling through a market in the city of Manado on the Indonesian island of Sulawesi when he was brought up short by a fish. In a cart being wheeled past him was a homely coelacanth, one of the most famous, yet most elusive, fish on the planet. Sporting fleshy, limblike fins, it originated 400 million years ago from the same stock of fish that gave rise to the ancestors of land-dwelling vertebrates called tetrapods. Among living animals, only lungfish are closer kin to tetrapods. But until just 60 years ago, no one knew that coelacanths were among the living–they were thought to have been extinct for some 80 million years. Then in 1938 fishermen hauled in a live specimen off the coast of Cape Town. Since then the fish have been found in a few other patches of the ocean near Madagascar, Mozambique, and the Comoro Islands. On the whole, biologists viewed these populations as tiny remnants of a once-great dynasty.

Thus, to see a coelacanth 6,200 miles away from its known habitat was decidedly odd. Unfortunately Erdmann was unable to buy and study the fish in the cart–he was on his honeymoon at the time–but he was so intrigued that he spent ten months interviewing local fishermen in search of another specimen. (Along the way he learned that on Sulawesi the fish is called raja laut, meaning “king of the sea.”) His persistence was rewarded this past July when a four-foot, 64-pound coelacanth (shown here) was caught in a deep-set shark gill net placed off the volcanic island of Manado Tua.

“It’s a very important discovery,” says Roy Caldwell, Erdmann’s postdoctoral sponsor at the University of California at Berkeley, “because coelacanths are in serious trouble in the Comoros–the population has probably halved in the last ten years. People there fish for oilfish and catch coelacanths as a by-product.”

Erdmann froze the Indonesian coelacanth shortly after its death, and a genetic analysis of its tissues is now under way to compare it with the African populations to see if it’s a separate species or not. “If they are related,” says Caldwell, “I’d bet Indonesia is the source population.” An ocean current flows from the Philippines past the Sulawesi Sea, through the Makassar Strait, and into the Indian Ocean, where it travels westward, to the Comoros.

COPYRIGHT 1999 Discover

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