|Smith , 1939|
The West Indian Ocean Coelacanth ( Latimeria chalumnae ) is a recent type of Quastenflosser (Coelacanthimorpha). The animals grow up to two meters long and are native to the east coast of South Africa. They are known in only a small number of individuals and are probably threatened with extinction. Based on studies of the stomach contents of caught Comoros coelacanth, it can be assumed that the animals are zoophages (carnivores).
In terms of evolutionary history , the lungs of this species have changed into a swim bladder . The brain of the Comoros coelacanth only takes up about one hundredth of the volume of the brain cavity , otherwise the brain cavity is filled with a fatty substance.
The first specimen of the species was discovered for science on December 22, 1938 by Marjorie Courtenay-Latimer , who worked as a senior curator (from 1945 called "Director") at the East London Museum east of Cape Town . The animal had been caught by a fish steamer under the command of Hendrik Goosen in the waters of the Indian Ocean off the South African coast near the mouth of the Chalumna . Since Courtenay-Latimer had become friends with Captain Goosen, she was regularly informed of the entry of the ship into the harbor and was given permission to select interesting individual pieces from the catch for her museum. The chemistry professor and amateur ichthyologist James LB Smith assigned the animal to the coelacids, which were previously thought to be extinct. Despite an immediate search for further specimens of this species, it was not until 1952 that another animal was caught near the Comoros , about 3000 km north of the first site. Like the first fish, it could not be kept alive after it was brought aboard the fishing vessel by the catchers. In the 1990s, further observations were made, including the discovery of a further population of the coelacanth, which is a species of its own and is known as the Manado coelacanth ( Latimeria menadoensis ).
Way of life
With its leg-like pectoral and ventral fins, the fish can move in a kind of “ cloister ”. For these alternating movements of the fins he has certain "neuromuscular coordination", as Hans Fricke calls it, in his nervous system . In his opinion, such coordination may have made it easier for the coelacanth relatives to step ashore. However, animals of the recent species do not walk around on the sea floor and their fins do not even touch the ground, for example when sneaking their prey, whereby the pectoral fins can be rotated 180 degrees around the longitudinal axis. When the coelacanth wants to swim fast, it uses its powerful caudal fin.
Coelacids are night hunters and drift swimmers who also use weak water currents to move. They use their large pectoral and pelvic fins for balancing.
During the day, the coelaceans stay in lava caves that are between 150 and 200 meters below sea level in the Comoros. Up to 16 animals live in the sometimes very spacious caves. At sunset the animals leave their cave one by one. Their forays lead them only a few kilometers away from their cave and to a depth of 700 meters.
If a prey fish swims in front of their mouths, then they can accelerate very strongly with one blow of their broad tail fin. A joint in the skull that is missing in other fish allows them to quickly open their mouths and thus to perform a lightning-like sucking-snap movement with which they quickly bring their prey into the mouth, which is surrounded by sharp teeth.
- Hans Fricke: In the realm of living fossils . In: Peter-Matthias Gaede (Ed.): The soul of the white bear . Hamburg 1998, ISBN 3-455-11256-0 .
- Hans Fricke: The fish that came from prehistoric times. The hunt for the coelacanth , CH Beck 2007, ISBN 3-406-55635-3
- Keith S. Thomson: The Coelacanth - A Living Fossil and Its Discovery . Birkhäuser Verlag, Basel 1993, ISBN 3-7643-2793-6 .
- Samantha Weinberg: The Coelacanth: the adventurous story of the discovery of an animal that has been believed to be extinct for seventy million years . Frankfurt a. M .: Fischer Taschenbuch Verlag, 2001. ISBN 3-596-15089-2 .
- Comoros Coelaceans on Fishbase.org (English)
- Tony Ribbink: Fossil Research Reshapes Conventional Wisdom Report on the South African research program African Coelacanth Ecosystem Program (Acep) from the Ministry of Science and Technology
- Latimeria chalumnae inthe IUCN 2012 Red List of Threatened Species . 2. Listed by: Musick, JA, 2000. Retrieved April 18, 2013.