|Posted on December 15, 2011 at 8:35 PM|
The Coelacanth: An Evolutionary Contradiction Slowly Reveals Its Secrets
Professor James Leonard Brierley Smith stared at the page in disbelief. The day was January 3, 1939, and a letter had just arrived from a Miss Marjorie Courtenay-Latimer who was the curator at the East London Museum, South Africa. Courtenay-Latimer was writing to Smith, a South African chemistry professor who had taught himself ichthyology, to get his help in identifying a strange fish she had just obtained as a museum specimen, but could not find in her reference books. Even though the chairman of the museum's board of trustees dismissed the animal as just a "rock cod," she thought there was something special about it.
The fish, reported Courtenay-Latimer, had been part of a catch made by the trawler Nerine off the South African coast near the Chalumna River on December 21st, 1938. The fish survived for several hours on the ship's deck, during which time it snapped at the captain's hand. The captain, Hendrik Goosen, thought the five-foot long, pale blue animal was inedible, but decided to keep it for Courtenay-Latimer, who often bought unusual fish for the museum's collection.
Courtenay-Latimer almost didn't make the trek down to the docks that day because it was hot and she was busy, but she felt she should wish season's greetings to the ship's crew. It was fortunate she did. She saw the strange blue fish and, as she said later, declared it was "the most beautiful fish I had ever seen..." She bought the animal and proceeded to take it back with her. After an argument with a cabbie who didn't want to take the smelly carcass in his taxi, Courtenay-Latimer got it to the museum. However, once she was there she had no refrigeration facilities in which to keep such a large specimen and neither the local cold-storage warehouse or the mortuary would cooperate. Turning to a local taxidermist, she had the animal and its viscera preserved as best she could. Then she wrote Smith telling him the story and including a sketch of the unusual animal.
Smith was at his vacation home in Knysna when the letter arrived. The letter, sketch included, sent his mind reeling. He knew exactly what type of fish it was based on the description. It was a Coelacanth (pronounced 'seel-uh-kanth'), a member of a group of fish called the Crossopterygii. The only problem with this conclusion was that the coelacanth and the Crossopterygii were thought by evolutionary scientists to have gone extinct along with the dinosaurs some sixty-five million years before.
The finding of a the Coelacanth was said to be akin to "finding a live dinosaur roaming the earth."
It was imperative that Smith go in person to examine the specimen. If he announced to the public that a live coelacanth had been discovered, and if he was wrong, he would be the laughing stock of the ichthyological world. Unfortunately, commitments he could not break kept him away from East London until mid-February. Wanting to remain noncommittal, Smith wired Courtenay-Latimer the message "Save viscera...fish interesting." This gave Smith time to borrow a book from Dr. K. H. Barnard on the Crossopterygii and examine some scales Courtenay-Latimer sent him that had come off the fish when it was mounted. They looked like what he would expect from a member of the Crossopterygii family.
Finally he arrived in East London on February 16th. Smith would later write in his book Old Fourlegs, The Story of the Coelacanth:
"We went straight to the Museum. Miss Latimer was out for the moment, the caretaker ushered us into the inner room and there it was the—Coelacanth..." Smith was not prepared for his own reaction at the sight of the creature, and he was so excited he began to shake. "Yes, there was not a shadow of a doubt, scale by scale, bone by bone, fin by fin, it was a true Coelacanth. It could have been one of those creatures of 200 million years ago come alive again."
Smith named the fish Latimeria chalumnae in honor of Courtenay-Latimer who had spotted it and taken the time to preserve it. Smith, with the help of his wife, worked hard for four months to complete a scientific paper announcing the remarkable discovery to the world in June of 1939.
Mark Erdmann, a marine biologist from the University of California, was enjoying his 1997 honeymoon vacation in Indonesia when his new bride asked about a strange blue fish she saw in the market. Erdmann's mouth dropped open as he recognized the animal as a coelacanth. Erdmann knew that the fish was a member of a rare species and that until 1938 scientists had thought it had gone extinct with the dinosaurs. He also knew that at one time the fish was only thought to have lived off the Comoro Islands near Africa, but figured that they must have been discovered in Indonesia since then. It wasn't until Erdmann posted his honeymoon pictures, including one of the fish, on the Web, and got a call from two Coelacanth researchers at the University of Guelph in Ontario, Canada, that he realized he'd stumbled upon a major scientific discovery: The Coelacanth had an additional habitat some 6000 miles away from the original ones.
Despite the excitement of the find, the internal organs of the fish had not been preserved for examination. Smith knew it was important to find another, intact specimen so it could be completely described. No more coelacanths were found off the coast of South Africa in the next ten years and Smith became convinced that the one that had been netted by the Nerine was a stray. Smith thought that the home grounds of the creature might be north near the Mozambique channel, so he had posters printed in English, French and Portuguese with a drawing of the Coelacanth. The posters, which offered a reward of one-hundred pounds to anyone who could turn in a complete beast, were distributed in the surrounding area.
In December of 1952 they got a cable from an acquaintance, Captain Eric Hunt, who was in the Comoros Islands, saying that he had taken possession of a coelacanth and was trying to preserved it for Smith with the small amount of formalin that he had. The fish had been caught by a man named Ahamadi Abdallah on the island of Anjouan. Abdallah was about to clean the fish he'd caught when a local teacher showed him one of the leaflets printed by Smith. There was a picture of the fish along with the instructions "Do not cut it or clean it or scale it, but take it at once to some responsible person." Legend has it that Abdallah dragged this 82-pound cargo twenty-five miles over mountains by foot, but in reality he probably hitched a ride on a truck. Once on the other side he presented it to Hunt, who recognized it as the fish Smith was seeking.
Smith immediately wanted to travel to the Comoros, but there were no commercial airports and what private airfields there were had problems getting fuel. Smith was concerned knowing that the Comoros had no refrigeration facilities. He wasn't sure if Hunt had enough formalin to properly preserve the specimen in the heat. Also, since the fish had been caught on French soil there was a danger that it would be claimed by the French. Smith finally got the South African prime minister to give him a military plane for the trip. The plane landed and after an agonizing delay caused by a courtesy call on the governor, Smith got to Hunt's ship where he examined the specimen. Smith later admitted during a live radio program that he cried when he first saw the fish. Hours later he was on his way back home, through a torrential rain. Smith was right about the French. After he left, the government banned foreign scientists from collecting coelacanths for the next decade and a half.
In 1991 scientists got a better understanding of the fish when Mike Bruton, of the JLB Smith Institute of Ichthyology joined with Hans Fricke, of the Max Planchk Instate to study the fish off the Comoros Islands. Fricke had built his own submarine so he could study the Coelacanth in its natural habitat. The animal hides in underwater caves some 300 to 700 feet down during the day and comes out at night to feed.
Local Comoran fishermen had been aware of the carnivorous Coelacanth (which is Greek for "hollow spine") for years before Smith's discovery, but since it was not edible they had not been interested in it, though it had been given the Comoran name Gombessa.
Originally it was a concern that the Coelacanth might have a very limited range and that overfishing along the Comoros Islands might wipe it out. Scientists were amazed when in 1997 another Coelacanth was discovered by an American scientist in Indonesia more than 6000 miles away from the Comoros. In October of 2000 divers off South Africa happened on three Coelacanths in the St. Lucia Marine Protected Area. These findings suggest that the original fish caught by the Nerine was not a stray and that this "living fossil" may have a much wider range than was first thought.
The class of fish to which the Coelacanth belongs is thought by evolutionists to have appeared some 400 to 350 million years ago. They theorize that it is closely related to the first four-limbed land animals. All Coelacanths, living and fossil, are classified as members of a group of fishes called Crossopterygians. It is this group that most evolutionists believe evolved into amphibians and all land vertebrates—including humans.
Before the discovery of living Coelacanths, evolutionists assumed that the fish's internal organs would be “part way” evolving from those of ordinary fish to those of amphibians.
But the living Coelacanths showed no evidence that their soft parts were starting to adapt for use on land. So it was conceded that the Coelacanth was obviously not the ancestor of amphibians after all.
Consequently, evolutionists looked for another type of fish that would fit their belief that fish evolved into those creatures that exist both on land and in water—the amphibians. In spite of having no actual evidence, they decided that another member of the Crossopterygian group of fishes—the rhipidistian—might be that long-sought-after transitional form. How did they arrive at that conclusion? The idea grew out of their study of similarities in skeletons of rhipidistians and what they believe were “early” amphibians. But in reality there is a vast difference between rhipidistians and amphibians.
Even using the evolutionists' time scale, which many scientists dispute, the Coelacanth is the same fish it supposedly was hundreds of millions of years ago. It is positively staggering to conjecture that the Coelacanth could remain so stable all this time, both genetically and morphologically, while its cousin the rhipidistian was supposedly evolving the mind-boggling number of changes required to transform it eventually into a human. Rather than being a landmark discovery in support of evolutionary theory, the evidence from the Coelacanth is good evidence for a young earth, as it shows that DNA, the genetic code of life, has remained stable in this species throughout time.
To this day, the name Coelacanth remains synonymous with the concept of "living fossils" and great natural history discoveries. But new research just published also reveals how little we still know about this fish, despite it being the subject of intensive scrutiny and excitement for more than 70 years.
A team of scientists based in France and Germany has just summarized the results of a 21 year study into Coelacanths living in the Comoros Islands, in the western Indian Ocean.
That in itself is impressive.
After its initial discovery in South African waters, another was not sighted by western scientists until fourteen years later, when a few fish were found swimming off the Comoros. The fish was not filmed alive until the BBC, by sheer coincidence, took some footage for the program Life on Earth broadcast in 1979, and the first photos of the fish in its natural habitat were not taken until 1988.
Considering how enigmatic the coelacanth has been, it is remarkable that a population study now exists of the fish extending over more than two decades.
The study was done on Latimeria chalumnae by Hans Fricke and colleagues of the Max Planck Institute for Marine Microbiology in Bremen, Germany.
Latimeria chalumnae is a deep blue variety of Coelacanth that has been sighted around Africa, off the coasts of South Africa, Mozambique, Kenya, Tanzania and Madagascar. It is one of two species of Coelacanth; the other, Latimeria menadoensis, is a brown fish found much more recently in Indonesia.
The scientists used remotely-operated vehicles to descend into the sea and survey a 5-mile-long stretch of coastline around Grand Comore inhabited by Coelacanths. The ROVs followed the fish into the caves in which they live, filming and photographing individuals, which are recognizable by the pattern of white spots on their blue bodies.
They have made some wonderful discoveries.
Coelacanths, it seems, are peaceful animals that do not act aggressively toward one another, even when groups of up to 16 fish share the same cave.
Females are markedly larger than males, but there does not appear to be any breeding purpose to their gatherings.
During the day, the fish live at a depth of 560-790 feet along a steep volcanic landscape of caves, and at night they drift down to depths of 1640 feet to feed, coming back to their caves in the morning to rest.
The survey reinforces the impression that perhaps just 300-400 coelacanths live at Grand Comore and that the fish do not tolerate waters above 72 degrees Fahrenheit particularly well, as many fish disappeared from the study area in 1994 when the water warmed, returning later.
The study demonstrates how much our understanding of these wonderful fish has improved in the past few decades.
Other research during this time has shown that Coelacanth embryos develop for three years, the longest recorded for any vertebrate.
Coelacanths also appear to have the lowest metabolic rates among vertebrates.
But the study by Fricke’s team, published in the June 2011 issue of Marine Biology, also gives away how much more we still do not know.
For example, during the entire survey period, the team did not record a single subadult, juvenile, or baby Coelacanth. They did not spot one in the Comoros, and have never spotted one in separate expeditions to study the fish off Indonesia, South Africa or Tanzania.
Only a single baby Coelacanth has ever been sighted. It was filmed by different researchers in 2009 at a depth of 525 feet.
It remains a mystery where Coelacanths give birth, where the young go, or why they do not live with the adults, information which is vital to the preservation of such a rare species. Scientists also continue to have little idea regarding the life expectancy of these ancient-looking fish.
The survey by Fricke’s team confirms that Coelacanths can live for at least 21 years; they observed the same fish at the start and at the end of the survey, while 17 fish were sighted 19 years apart. This confirms that it is not unusual for a Coelacanth to live for two decades at least—the first real evidence of a Coelacanth’s minimum age.
The survey also allowed them to calculate the mortality rate of the fish, based on how often the same fish were observed again over the following years.
Their best estimate is that Coelacanths have a mortality rate of 0.044. That means that out of a collection of 100 individuals, at least one would be expected to still be living 103 years later. The same data can be used to make another mathematical projection suggesting that Coelacanths can live for between 95 and 117 years old.
Other deep water fish have been found to live for around 100 years, so it's plausible that Coelacanths may also reach this epic age. However, this remains uncertain, as does the Coelacanth's average age.
One bit of positive news is that accidental catches of Coelacanths around the Comoros are declining steeply.
Fishermen in the area used to fish using a long line and hook from motorless canoes called galawas, and would occasionally snare a Coelacanth while fishing at night for oilfish.
Nowadays, the fishermen use motorized boats called vedettes to travel further out to sea—mostly avoiding the Coelacanth's habitat. Between 1954 and 1995 two to four Coelacanths were taken each year. But after 2000, that has fallen to an average of only 0.3 Coelacanths.
These fishermen are the only known cause of mortality for Coelacanths; Fricke’s team's survey occasionally encountered large sand tiger sharks in the area but never witnessed any predation on Coelacanths by such larger fish. Unfortunately, as with any extremely rare species, threats to their very existence never seem far away.
In Tanzania, another home to Coelacanths, fishermen once caught edible small fish from shallow waters. But once these were depleted, the fishermen took to using deep-water gill nets. Since 2003, when these nets were first used, more than 80 Coelacanths have been caught, and the number is increasing each year.
That is of huge concern for this population of Latimeria, and it also reinforces how similar circumstances might eventually occur around the Comoros, one of the fish's remaining known strongholds.
One solution, if it can be arranged with the people of the Comoros, is to set aside a protected area along the southwest coast of Grand Comore, a policy supported by Fricke’s team and other researchers.
In the end, science still knows so little about this ancient fish that, considering it was already written off as extinct, it would be more than tragic to let it go extinct now.
This is a fish that has survived virtually unaltered for at least thousands of years. Yet we risk it becoming extinct in just a handful of years due to subtle shifts in the way we choose to fish, and treat our marine life.
Sadly, if it does disappear, it will do so long before we've had a chance to truly understand it.