Sunday, September 27, 2020

How many coelacanths?

We all know the basic story of the coelacanth, the animal the term "living fossil" came to be most identified with.  




In 1938, a South African trawler pulled up a fish about the size of Marjorie Courtenay-Latimer, the museum curator who spotted the strange blue trophy.  It was a coelacanth, descended from a line of lobe-finned fishes that had supposedly gone extinct 66 million years ago. Latimeria chalumnaewas certainly the most famous piscine discovery of the 20th century. It appeared this one had strayed from the species' usual range,  later confirmed as the area immediately surrounding the Comoro Islands.  In 1999, another species was described, thousands of miles east of the Comoros.  Dr. Mark Erdmann, a biologist, and his wife Arnaz, a naturalist, were on honeymoon   on the Indonesian island of Sulawesi, when she saw something odd on a fisherman’s cart.  “Isn’t that one of those fossil fishes?” she asked.  That species is now known as Latimeria menadoensis.  (An African population, although not a new species, was confirmed in 2000.)

Now we have more - or we might.  I missed the announcement of this in January - I've no idea how - but two of the Indonesian populations are separated by some 13 million years. We  may have another species, or a group of related species (there's a LOT to be analyzed concerning the Indonesian coelacanths)  where the boundaries are a bit fuzzy, called a species complex.  A writer for Reef Builders notes, "The evidence comes from genetic analysis of a single sample of a Coelacanth that was fished up from 300 meters deep in West Papua, that was ‘mostly eaten’ before some tissue could be preserved."  So we will see what comes out of this study and efforts to find other specimens to match it..

Oddity: In 1995, reports circulated about a coelacanth being caught off Jamaica. This startling tale made some newspapers, but no one was able to confirm it. Dr. George Brown, founder of a coelacanth conservation group, the Society for Protection Of Old Fishes (yes, the acronym is SPOOF), reported he’d heard nothing about it. Dr. Karl Shuker, an English zoologist who also tried to verify the story, believes it was a hoax or a case of mistaken identity. 

There rests the mystery of coelacanth distribution.  It’s likely there are (or were) populations between the Comoros and Indonesia.  It’s also still possible we’ll find coelacanths in other parts of the globe.  Perhaps this famous fish, while still fascinating and important, isn’t quite as rare as we thought. 





No comments: