What is a Coelacanth?
Coelacanths (pronounced see-le-canth), meaning “hollow spine” in Greek, are lobe finned fish with the pectoral and anal fins on fleshy stalks. The tail fin is divided into three lobes, the middle one of which also has a stalk. The coelacanth has modified cosmoid scales, that are thinner than true cosmoid scales, that can only be found on extinct fish. About 125 species are known from fossils; they were considered to be index fossils (i.e. they indicated the age of the rock), extinct since the end of the Cretaceous, until a live one turned up off the east coast of South Africa in 1938. Coelacanths can be found in the Comoros, Sulawesi (Indonesia) and St. Lucia Marine Protected Area (South Africa). These are the oldest living fish that are known to date. They are believed to be the ancestors of many modern day amphibians due to the lobed fins and location of the fish. Picture and more information: http://en.
The coelacanth is a lobe-finned fish, similar in form to the ancestor of all terrestrial vertebrates. It was a coelacanth-like fish that originally evolved legs and began to walk on land 360 million years ago. Coelacanths were presumed to be extinct for at least 100 million years, only being found in the form of fossils up until a living specimen was found near the Comoros Islands, off the east coast of Africa in 1938, causing an international sensation. The word to describe an group that was presumed extinct but was subsequently discovered alive is “Lazarus taxon.” The coelacanth is a large fish, weighing an average of 80 kg (176 lb) and measuring as long as 2 m (6.5 ft). By examining their ear bones, we know that coelocanths are long-lived — with some living as long as 80 to 100 years. There is an African species, which is deep blue in color, to help it camouflage, and an Indonesian species, which is brown. Coelacanths have extremely sensitive eyes and only go out to hunt at night.
It’s a fish that first appeared in the Earth’s oceans about 400 million years ago. The coelacanth was thought to have died out along with the dinosaurs about 65 million years ago, but in 1938 the fish was found to be living in the sea off the coast of South Africa. The coelacanth is a very important animal for understanding the process of evolution, because it shows signs of the transition from fish to land-dwelling animals with four legs. Currently, 20 universities and other organizations in Japan are working together to unlock the mysteries of biological evolution by studying the coelacanth. They have been assisted in their endeavors by the donation of two rare coelacanth specimens from Tanzania, a country on the coast of eastern Africa.
It is a bony, marine, lobe-finned fish in the Class Osteichthyes, Subclass Sarcopterygii, Order Coelacanthini (BBC, 1998). The first species found was named Latimeria chalumnae (Coad, 1998). There have been many specimens found all over the world, which have each been given different species names. The coelacanth is the last of the lobe-finned fish and all the fish today are thought to have evolved from these (BBC, 1998).
