On the Trail of the Coelacanth, a Living Fossil
By Susan L. Jewett
She had no way of knowing what would happen. Nobody did. But Arnaz Mehta Erdmann was about to notice something that would rewrite a chapter in the history of biology.
Not that she had been looking. In fact, she and her husband Mark were on their honeymoon, strolling through the outdoor market in Manado, a town at the tip of an island called Sulawesi in Indonesia. Hundreds of fishermen work the surrounding Celebes Sea, and on that September day last year the marketplace was teeming with variety.
None of the catch, however, looked remotely like the weird thing that Arnaz saw being pushed along in a wooden cart. It was several feet long, with stumpy, lobed appendages where other fish have conventional fins. It was covered with heavily armored scales.
Arnaz called Mark's attention to the creature. To most folks, the fish might have been little more than a curiosity, but Mark was a marine biologist with a recent PhD from the University of California at Berkeley, resulting from his study of mantis shrimps in Indonesia. He recognized it immediately as a coelacanth, a "living fossil" whose body plan hadn't changed appreciably in hundreds of millions of years.
But that didn't make sense. Mark had been taught that coelacanths not only were extremely rare but also had never been seen outside the western Indian Ocean. He photographed the creature and asked the fisherman where he had obtained it. Apparently, it was local. Surprised, Mark reluctantly assumed that the living fossils had been observed in the western Pacific and that somehow he had missed hearing of the discovery.
Not until he and Arnaz returned to Berkeley did Mark learn that coelacanths had never been sighted east of Madagascar. They definitely weren't supposed to be in Indonesia, about 6,000 miles away. But then, only a few decades before, they weren't supposed to be anywhere at all.
Sixty years earlier, the coelacanth (pronounced SEE-la-kanth), previously known only through fossil specimens, had shocked the scientific world when a living specimen was discovered in South Africa. The news was akin to finding a living dinosaur wandering Earth today.
Marjorie Courtney-Latimer, a young curator of the East London Museum in South Africa, was building a scientific collection of fishes and had arranged with a local fisherman, Capt. Hendrik Goosen, to collect specimens for the museum.
On Dec. 22, 1938, Courtney-Latimer received a phone call: Goosen's trawler was at the dock with a large haul of fish taken near the mouth of the Chalumna River. Although pressed for time and not wanting to travel to the docks, she felt that the least she could do for the ship's crew was "to go down and wish them the compliments of the season."
Among many specimens strewn across the deck, she saw a very strange fish five feet long. "I noticed a blue fin sticking up from beneath the pile," she wrote. "I uncovered the specimen, and, behold, there appeared the most beautiful fish I had ever seen."
Courtney-Latimer didn't know what the fish was but had a hunch that she should save it. The local hospital morgue turned her down, as did the town's only cold-storage facility. So she wrapped it in rags soaked in formaldehyde. After several days, it became evident that this method was not sufficiently preserving the fish, so she opted for taxidermy and, as a result, preserved only the skin and a few hard parts.
Using one of the few books available to her, she traced the fish, uncertainly, to the family called coelacanths [above]. The chairman of her museum's board of trustees dismissed it as a rock cod.
Undaunted, Courtney-Latimer sent a sketch and description to J.L.B. Smith, then a chemistry professor and resident fish expert at Rhodes University in Grahamstown. When he finally received the letter, Smith was dumbfounded. Could it be true? The drawing clearly depicted a coelacanth. Yet they presumably had become extinct 80 million years earlier!
Smith wired Courtney-Latimer: "Save viscera . . . fish interesting." But the message arrived too late; the organs had rotted.
Courtney-Latimer's persistence, against great odds, paid off on Feb. 16, 1939, when Smith traveled to New London and confirmed her suspicion. The fish was named Latimeria chalumnae in honor of the discoverer and the site of the find.
It took 14 years to find another one. Smith searched the waters around South Africa and the eastern coast of Africa, eventually preparing handbills describing the fish and offering a reward.
Finally, those handbills made their way to the Comoro Islands where, on Dec. 20, 1952, a specimen weighing 88 pounds was captured. After a hurried plane ride, Smith held a coelacanth in his hands, causing him to weep with joy.
Before the Erdmanns' discovery in Indonesia, about 200 specimens had been captured, half of which were available for scientific study. All were from the western Indian Ocean, primarily around two of the Comoro Islands off the northwestern coast of Madagascar. Several "strays" have been captured off South Africa, Mozambique and Madagascar.
The total coelacanth population is thought to be 500 or fewer, a number that would threaten the survival of any species. So in accordance with an international treaty known as the Convention on International Trade of Endangered Species, the coelacanth was added to Appendix I (threatened with extinction) in 1989.
This treaty forbids international trade for commercial purposes and regulates all trade, including sending specimens to museums, through a system of permits.
Having learned all this before his return to northern Sulawesi last November, Mark Erdmann began trying to find the fisherman he had met in the market and to determine whether the fish had been captured in Indonesian waters. He had studied the ecology of coral reefs in the area for seven years and was fluent in the language.
After talking to about 200 fishermen, he located the one from the market and three others who convincingly claimed to have captured coelacanths.
At that point, an ethical dilemma arose. Mark wanted to retrieve a specimen for science and report the discovery, but he could not induce the local fishermen to fish purposely for a rare and endangered species. His strategy was to provide sufficient compensation to make it worthwhile for the fishermen to bring the fish to him if caught but not so much money that they would be enticed to abandon other pursuits.
Naturally interested was the Smithsonian Institution's National Museum of Natural History, which has the world's largest research collection of preserved fishes, including a coelacanth from the Comoros.
In my capacity as manager of the collection, I had been in contact with Mark since shortly after his honeymoon discovery, and we had established an appropriate plan for what to do with a specimen if one was caught.
It would have to be preserved properly, but before doing so, tissue samples would be taken for DNA analysis. Those samples would help determine whether the Indonesian coelacanth is a member of the same species as the Comoros specimens.
After advising Mark about appropriate organs to sample, I equipped him with a liquid nitrogen container for storing the tissue samples, and the Smithsonian provided funding to keep a whole specimen frozen until it could be fixed in formaldehyde and permanently preserved in ethyl alcohol. So he was ready on the morning of last July 30 when the critical moment came.
Sharks bring a handsome price in that part of the world, and Mark's prize surfaced in a deep-water shark net set by fishermen off the volcanic island of Manado Tua in northern Sulawesi. The net, lowered at dusk and raised at dawn, is about 330 feet long and 33 feet high and works by entangling fish that swim into it.
On this morning, it yielded a spectacular catch from about 400 feet -- a four-foot coelacanth weighing 64 pounds.
The fisherman, Om Lameh Sonatham, brought the fish, still alive, to Mark's house along the shoreline of the neighboring island. The fish is known locally as raja laut (king of the sea) and apparently has been captured at a rate of two to three a year for several years.
The fish lived for nearly six hours, allowing Mark and Arnaz to document photographically its coloration, fin movements and general behavior. Superficially, it looked the same as those found in the Comoros except that the background color was brownish-gray rather than bluish.
Although the fish was greatly stressed, as any would be when raised from such depths, it demonstrated quite effectively the typically fantastic movement of its lobed fins. In the Comoros, recompression efforts have failed, and no specimen has stayed alive for more than a day.
Mark donated the specimen to the Museum Zoologicum Bogoriense (MZB), part of the Indonesian Institute of Sciences (LIPI). He also invited me to Indonesia to assist with preservation of the coelacanth and to meet with LIPI officials to discuss a future specimen donation to the Smithsonian.
After we shipped the frozen fish to Jakarta, MZB officials transferred the specimen to their new state-of-the-art museum facility in Cibinong between Bogor and Jakarta. There we jointly performed more dissections. Finally, we preserved the coelacanth by injecting formaldehyde, followed by immersion in a solution of formaldehyde. After an appropriate fixation period, the specimen was transferred to ethyl alcohol for long-term storage and display in the MZB.
Mark's report of the discovery, coauthored with Roy L. Caldwell, his graduate adviser, and a colleague from LIPI, M. Kasim Moosa, appeared in the Sept. 24 issue of the journal Nature. Unconfirmed sightings are now being reported elsewhere in Indonesia, and researchers are gearing up for underwater exploration.
Where else do the living fossils live? How plentiful are they? These and related questions will keep scientists occupied for years.
Susan L. Jewett is collection manager in the Division of Fishes at the Smithsonian Institution's National Museum of Natural History.
© Copyright 1998 The Washington Post Company