A primitive type of fish, it was thought to have been extinct for 70 million years until one was caught in 1938 (see below).

It's a living fossil, a relative of the lobe-finned fishes that evolved into land creatures. Among the intriguing characteristics of this fish:

  • They are vertebrates without a backbone. Although we commonly think the two are synonymous, membership in Vertebrata does not require vertebrae - the coelacanth's simple fluid-filled notochord suffices for membership in the club.
  • They have a tri-lobe tail, one more lobe than "normal" fishes.
  • They are viviparous, giving birth to live young, like some species of shark. Modern fishes are oviparous (egg laying).

The coelacanth is endangered due to its very small population base. It doesn't help that the species' unlikely longevity works against it - the notochord fluid is said by some to prevent aging. No one has tested this clinically, of course, but it's highly unlikely.

Nonetheless, the idea of eternal youth has allure almost as ancient as the coelacanth itself. Imagine if it were true! Someday there might be huge fish farms of coelacanth. Some hideous factory operation would drain their notochord fluid into tiny jars, to be sold at cosmetic counters for exorbitant amounts.

Coelacanths are quite different from all other living fishes. They have an extra lobe on their tail, paired lobed fins, and a vertebral column that is not fully developed. They are the only living animal to have a fully functional intercranial joint (a division which separates the ear and brain from the nasal organs and eye, and allows the front part of the head to be lifted when the fish is feeding). Perhaps the most interesting feature of the Coelacanth however, is that it has paired fins which move in a similar fashion to our arms and legs.

On the 30th July 1998, a Coelacanth population was discovered by American and Indonesian scientists off Sulawesi, Indonesia. This is about 10,000 km east of where Coelacanths were previously known to occur in the Western Indian Ocean. The local people from Sulawesi were familiar with the Coelacanth and had a name for it, raja laut or 'king of the sea'.

The first living Coelacanth was discovered off the east coast of South Africa, at the mouth of the Chalumna River, a few days before Christmas in 1938. The fish was caught in a shark gill net by Captain Goosen and his crew, who had no idea of the significance of their find, but still thought the fish bizarre enough to alert the local museum in the small South African town of East London.

The original discovery of the Coelacanth in 1938 is still considered to be the zoological find of the century. This 'living fossil' comes from a lineage of fishes that was thought to have been extinct since the time of the dinosaurs.

Coelacanths are known from the fossil record dating back over 360 million years, with a peak in abundance about 240 million years ago. Before 1938 they were believed to have become extinct approximately 80 million years ago, after mysteriously disappearing from the fossil record. How could the Coelacanth disappear for over 80 million years and then turn up alive and well in the twentieth century? The answer seems to lie in the fact that the fossil Coelacanths appear to have lived in environments conducive to fossilisation. The modern Coelacanths, both in the Comoros and Sulawesi, however were found inhabiting caves and overhangs in vertical marine reefs at about 200m depth off newly formed volcanic islands, an environment that is particularly poor for fossil formation.

When the coelacanth from Sulawesi was first discovered, the only obvious differences between it and the coelacanths from the Comoros Islands was the colour. The Comoros coelacanths, Latimeria chalumnae, are renowned for their steel blue colour, whereas specimens from the 'new' population are reported to be brown. In 1999 the Sulawesi coelacanth was described as a new species, Latimeria menadoensis

Information taken from the Australian Museum Online and http://www.dinofish.com

Log in or register to write something here or to contact authors.