Latimeria chalumnae and Latimeria menadoensis
The Coelacanth is the oldest known living example of a lob-finned fish, a species which is the presumed ancestor of all tetrapods on Earth. Originally thought to be extinct, their discovery in the early 1930s created a global sensation. They were often referred to as a “living fossil” because it was initially assumed they hadn’t evolved much from the prehistoric examples. Additional research disproved this theory however and we now know that the modern Coelacanth is a unique species when compared to its ancient ancestors. Still, it has many features not seen in any other living fish, including vestigial air-breathing lungs and lobbed fins which may have been the precursor to legs in some ancient species.
The fish’s thick, heavy body is dark blue with distinctive white spots which scientists use to distinguish one individual from another. The scales are thick and help to armor the fish from predators. When swimming, the fish moves its fins similar to how a four-legged animal would walk across the ground, prompting some divers to describe it as a “walking fish.”
Because they are slow-moving and occupy waters with modest food sources, the Coelacanth is an opportunistic hunter. Often it will hang in place for long periods of time, lunging at and consuming any animal which happens by. Its primary diet includes squid, fish, eels, small sharks, and cuttlefish. To help sustain itself over long periods without food, scientists now believe the fish has the ability to lower its own metabolism.
There are two distinct populations of Coelacanths. The Indian Ocean population is known as Latimeria chalumnae and occupies the deep waters off the east coast of Africa and around the island of Madagascar. The second is known as Latimeria menadoensis and is located much further east in the waters near Indonesia. Both populations are deep water fish, living in the caves and crevasses of heavily eroded volcanic slopes.
Coelacanths are not harvested by humans, but their limited numbers and genetic diversity means they probably do not exceed one thousand individuals worldwide. Because of these small populations, they are considered an endangered species throughout their entire range.