Monday 29 September 2014

Coelacanth

It has been a while since I last posted here. Over the last few months I have been thinking of starting up again so here I am. I found doing a creature every week to be too much like work so now I am going to be doing it once a month so I enjoy it.


Since I am bringing back to life my dead blog I may as well follow suit with that theme so I present to you the Coelacanth (pronounced see-la-canth). The Coelacanth which is nicknamed “The Living Dinosaur” or “Living Fossil” is an ancient fish that was thought to be extinct since the end of the Cretaceous period (66 million years ago) but on December 22, 1938 it was discovered by museum curator Marjorie Courtenay-Latimer among the catch of the angler Captain Hendrick Goosen. The captain was angling off the Chalumna River on the east coast of Africa. This fish is the best example of a Lazarus Taxon which is a species thought to extinct for one or more periods of time only to be reappear much later. Maybe the Tasmanian Tiger or the Dodo bird or maybe even the Pinta Island Tortoise (Lonesome George) could someday become a Lazarus Taxon.

The Coelacanth is basically an ancient fish, mostly unchanged for millions of years. Since it was first discovered there have only been two species found; the first one being the West Indian Ocean Coelacanth that Marjorie found and the other being the Indonesian Coelacanth. The Indonesian Coelacanth was discovered on September 18, 1997 by a couple named Arnaz and Mark Erdmann on their honeymoon at a local market in Indonesia. Mark thought it was West Indian Ocean Coelacanth but it was brown instead of blue. An expert saw the pictures and identified it as a separate species. It just goes to show that because humans cannot find a species, it does not mean it is necessarily extinct.

The Coelacanth is a lobe-finned fish which is related to a lot of its characteristics. They are large, fat fish covered in cosmoid scales which act as amour. Cosmoid scales have four layers, with the first being dense bone, next being spongy bone, then one of dentine and then one of enamel. They have eight fins: two dorsal, two pectoral, two pelvic, one anal and one caudal fin. They can maneuver very efficiently because of this, they have been seen doing headstands and swimming belly up. They seem to like showing off. They generally do not swim much though, they prefer to drift with swells up and down in the water. They are usually about 1.8 meters (5 feet) long and weigh around 60kg (132lb) so they are heavy suckers! As you can see it does look like a prehistoric fish.

The cool thing about this fish is that it a close cousin of the lungfish meaning that it does have lungs. They have a “fatty lung” or a fat-filled single-lobed vestigial lung, similar to other fish’s swim bladder. So the coelacanth uses their lung like a swim bladder rather than breathing; they use their gills to breathe so that means the lung cannot breathe air.

Since they tend to live in deep sea they have evolved to see better in poor light environment. Theirs eyes are adapted to seeing low wavelengths and it has evolved to see blue better than any other colour. To hear it has a basilar papilla which is the same thing lizards use to hear so it feels vibrations rather than actually hearing anything the way you and I do. The coelacanth is the only fish alive today with ears like this. Hearing vibrations is better as sound does not travel well in water but vibrations carry just fine.

Animal Crossing for Wii
The first time I have ever heard of Coelacanth was when I played E.V.O. (a Super Nintendo Game where you play a creature that evolves over our fantasized prehistoric past). You run into them a few times throughout the game to show that they stuck around a long time. I then looked up what the coelfish in the game was a reference of and learned something new. Who ever said video games do not teach you anything? There is also a Pokemon based off them called Relicanth the Longevity Pokemon, you can catch it in Animal Crossing, and there is a Digimon based after it called Coelmon. I watched Digimon but did not know that was supposed to be a Coelacanth.

Evo for Super Nintendo - Coelacanth is the purple fish on the right.
I nominate the coelacanth an Epic Creature this month because it’s a Lazarus creature, has a cool cosmoid scale armor and has lungs – all pretty rare for a fish!


See you next month.