Where is the Coelacanth?

Coelacanth

Latimeria chalumnae Smith, 1939

Here in the floor you see a sign saying KWASTVINNIGEN or lobe finned fishes. Therefore, somewhere a coelacanth must be around. Above your head you can see a model.

The lobe-finned fishes are a very special group of fish: they have bones and muscles in their fins. The more known fishes, like herring, turbot, plaice, or cod, are ray finned fish. They have muscles attached to the fins, but not in the fins themselves.

Is fish walking on land, in your opinion, an ordinary scene?
In South Sudan it sometimes is. There the White Nile River meanders through a swamp, called The Sudd. During the wet season (July/August), the Sudd floods, and a big shallow lake is formed. In that lake, the African sharp tooth catfish [Clarias gariepinus, (Burchell, 1822)] frolic and reproduce abundantly. Then the dry season comes with less supply of water and the lake dries, little pools and smaller streams remaining. Quite a lot of the catfish are trapped in those pools. The pools also dry. What happens to the trapped catfish? They walk on land to the next pool, or to a stream. On top of the gills, they happen to have an extra organ with which they can absorb oxygen from the air. When you live in such an environment, is it beneficial to have bones and muscles in your fins? Of course it is, and if so, you can easily adapt to a walking life on land. Moreover, that way the amphibians originated, in our opinion from the lobe-finned fishes.

The scientists thought this group went extinct 65 million years ago. Therefore, the discovery of a living Coelacanth was a scientific sensation. A museum curator named Marjorie Courtenay-Latimer discovered it. She worked as a curator of the new East London Museum in East London, South Africa. In 1936, she made an agreement with Hendrik Goosen, the captain of a trawler. Goosen fished for sharks, but he agreed to save interesting marine specimens. Courtenay-Latimer could inspect them and if valuable include them in the museum's collection.

On December 22, 1938, the trawler entered the harbour with several unusual fishes on board. The captain contacted the museum and said that he had several specimens on board that might be interesting. Courtenay-Latimer didn't really feel like going to have a look. She was very busy with the preparations for Christmas but after some hesitation she decided to go to the harbour anyway. At least she could wish the captain and his crew a Merry Christmas and a Happy New Year.

Latimeria

When Courtenay-Latimer arrived, a blue fin caught her attention. She pushed some fish aside and what emerged? Such a fish (arms spreaded), 150 cm long, with white dots. She had never seen a fish like that. The only thing she could determine was that it had to be a very primitive fish type. Courtenay-Latimer could persuade her taxi driver to carry the big fish (it weighed 57.5 kg) in the trunk of his car to the museum. On the 26th of December, a taxidermist mounted the skin but unfortunately the internal organs were corrupted and could not be preserved. Courtenay-Latimer contacted contact a friend of hers, James Smith, who was a lecturer in Chemistry at Rhodes University College. He was also an autodidact ichthyologist. He was always ready to help her classify fish specimens. She sent him a description and a drawing. James Smith immediately understood that the the drawing was very similar to a type of fish of which the scientists thought it had been extinct at the end of the Cretaceous period, 65.000.000 years ago. (The local fishermen though knew of it under the name gombessa.) After some research en examining the mount, he named it Latimeria chalumnae. The genus name is in honour of Courtenay-Latimer, the species name relates to the Chalumna River in the vicinity of which the fish was caught.

Mr Smith had offered 100 British pounds to anyone who could bring him another Coelacanth. However, it would take 14 years before another specimen was found. That one was caught near the Comores, an island group between South-Africa and Madagaskar. A place much more north than the Chalumna. Here lives a population. At day they hang around in the depth, but at night they hunt. When hunting they cab travel big distances.

These fish have changed very little over time.