Known as the "living fossil" this miraculous fish was first rediscovered in 1938. What makes these creatures so difficult to study? In this post, I'll cover some of what scientists have discovered about these elusive fish.
BY OLIVIA ISLAS
MAY 1, 2023
The two known species: Latimeria chalumnae and Latimeria menadoensis
Firstly, their preferred depths in the Twilight Zone (500-900 ft/152-243m) make them difficult to detect. Coelacanths (SEE-lə-kanths) have a shared anatomical appearance and size to goliath grouper since on the surface they seem like a typical large fish. Scientists searching for coelacanths are at a disadvantage when using radar alone because its hard to identify them without close inspection. It also doesn't help that coelacanths share a similar liking to hide in marine volcanic caves as grouper do. As you can see from the photo, the light spots and dark scales help them blend in with the terrain of their home. When these sneaky fish are found, the latimeria chalumnae dwell far off the coasts of Africa and Madagascar, and only latimeria menadoensis is found off Indonesia's coasts.
One of the most interesting things about coelacanth are the lobed fins and tail they have. They are not like regular fish fins with thin skeletal extensions, they are built out with bone just like your arm. So these fins function more like appendages and they are sometimes observed to walk about the ocean rather than the quick flick of a thin fanning fin. They have a jointed jaw that opens wide enough for them to swallow prey larger than its head. They can grow to about 6ft or 183 cm in length and weigh over 198 lbs, or 90 kilos.
Ever wonder what they eat? These fish are known as "passive drifters" and do what the name suggests by drifting along slowly with the current and eating the prey that floats nearby. This prey consists of squid, octopus, cuttlefish, and other fishes. Because food is scarce in the mesopelagic, the coelacanth has a slow metabolism which allows it to go for much longer periods of time without eating. Now just because they tend to swim slowly doesn't mean they cannot bolt away from danger. Personality-wise, coelacanths are not territorial, or particularly curious, they are relaxed fish that sometimes cluster in caves with others of the same species, but most often swims around alone.
Their main predators are us humans. We pose a threat when we accidentally catch them in what is known as "bycatch" in the fishing industry. The primary forces of habitat destruction for the coelacanths are as follows: Channel dredging which is dragging a large weighted net along the seafloor upsetting everything there and collecting it. And deep water port construction for large barges to come close to the shore, this often involves using submarine blasts to clear away rock and other tough inhibitors for builders permanently destroying the natural landscape. As a population of naturally limited numbers even hundreds of years ago, coelacanths are on the endangered species list and methods of incentivizing local fishermen to avoid catching these fish are in effect.
So, these are some of the things we know about the Coelacanth. If you would like to know more, follow the links to my sources. I hope you enjoyed the read! There is hope for this mysterious fish if we continue to care for our beautiful planet and all living in it.
All photo credits to: https://thelife-animal.blogspot.com/2012/06/coelacanth.html