Living Fossil: Story of the Coelacanth

by Keith S. Thomson

If you like fish (as animals, not as food), then you'll probably enjoy Living Fossil, by Keith S. Thomson, more than I did. Subtitled "The Story of the Coelacanth," ("seel-uh-canth"), it is about a fish that was, until recently, thought to have been extinct for about 70 million years. Unfortunately, the writing in Living Fossil is a little stilted, and that kept me from being drawn into the otherwise fairly interesting story of this fish's history, and significance.

Thomson is a decent storyteller, though, and I particularly enjoyed the early chapters of Living Fossil, which chronicle the first recorded catch of a coelacanth by a trawler in 1938; the efforts of Marjorie Courtenay-Latimer (curator of the East London Natural History Museum in Cape Province) to preserve that fish in the December heat of South Africa; the dramatic moments when J.L.B. Smith (of Rhodes University) realizes what this new fish actually is; and Smith's subsequent search for further specimens, a search which finally bore fruit in 1952 in the Comores islands, 14 years later and more than 1000 miles up the southeast coast of Africa.

Thomson's research is pleasantly meticulous. He is careful to give us all sides of any conflicting accounts, and quotes judiciously from the participants themselves. There are also some nice pictures, not only of the coelacanth, but of the people and places that are part of the story.

I got bogged down somewhat, though, when Living Fossil turned from the initial discovery and search for specimens to the story of how and why coelacanths are evolutionarily important. In tracing the early history of fish, for example, Thomson writes:

Of the early radiation of fishes it is fascinating that so many groups failed to make it past the Paleozoic (or even past the Devonian), while sharks and rays and the ray-finned bony fishes not only survived and replaced them but flourished in the Mesozoic and Cenozoic at levels of diversity far beyond anything seen in the Paleozoic.

Not incomprehensible, certainly, but neither does it let the eye and mind follow easily along.

There are places, too, where I could have used a little more explication: "The bony backbone then later developed twice in parallel - once in higher ray-finned fishes and once in lobe-fins/tetrapods." Thomson makes it relatively clear here that tetrapods (reptiles, amphibians, birds, and mammals) split off from fish very early in the evolutionary cycle, but I was still left wondering, after this single sentence, about that old classification "vertebrata" that I learned in grade school, and if and why it's still applicable to groups that evolved vertebrae separately.

The final chapters of Living Fossil bring the story up-to-date, with the latest answers to questions about coelacanth behaviour and physiology. Is it found only off the Comores? If so, why? If not, why has one never been caught elsewhere? And how did one get to South Africa? At what depth does the fish live? And, most puzzling, is it live-bearing (like guppies) or does it lay eggs? Here again Thomson's writing is not as smooth as I could hope:

The detailed dissections of the French group showed nothing in any of the female specimens to suggest that they were live-bearing. Indeed, as there is also no obvious intromittent organ in the male, the possibility of live-bearing seemed to be ruled out...

Couldn't he have done better than "as there is also no obvious intromittent organ in the male"? In the next paragraph, though, Thomson's story-telling builds enough suspense to make me want to read on for the answers:

The more scientists involved thought about this, the stranger it seemed. The French had already shown that there were no shell glands associated with the oviduct and, therefore, no way for the female to protect the egg with a tough case. But how could such a large egg, the largest egg of any known fish, be shed into the water with so little protection? How could it survive?

Living Fossil concludes with a laudable plea for conservation and caution in harvesting what may be a fairly uncommon fish. It is sad to see such a plea is necessary, even today, especially given that it is aimed primarily at other scientists, who are responsible for most of the coelacanth catches to date. Thomson has done an nice job of telling the story of this fish, and if you already have an interest in evolution, or fish, or both, give it a look.

© 1996, Greg Tillman.

latest update: May 30, 2001
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