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Today on Animal Fact Files we’re talking about coelacanths. Help keep our channel from going extinct by subscribing! Most people have heard of coelacanths because their discovery in the late 1930s was quite an astounding finding. These fish were believed to have lived in the time of dinosaurs and gone extinct along with them as evidenced by a lack of coelacanth fossils dating past about 65 million years ago. Their general lack of changes from their ancestors have given rise to the coelacanth’s nickname: the living fossil. Though, we all know that nick name isn’t exclusive to them!

Previously there were thought to be somewhere around 100 coelacanth species, though today there are only two - and they’re both facing extinction. Coelacanths live in ocean waters, typically staying between 220 to 2300 feet (70-700 meters) deep. They spend the daytime hiding out in rocky caves with which their speckled bodies blend in perfectly. Coelacanths come in either blue or brown with white spots, and those spots are so unique to each individual that scientists can actually identify specific coelacanths based on their coloration. During the night, they search for food in the form of other fish and cephalopods. For the most part, they move like lumbering giants, and considering they can reach nearly twenty feet (6 meters) in length, they are certainly quite large, however, if they need to make quick movements they absolutely are able to.

Coelacanths are fish and their closest living relatives are lungfish, which should give you some insight into why they’re not like most fish we know; they have certain anatomical abnormalities not seen in any other known animal species. For starters, their heads have a hinge that allows them to open their jaws wide giving them plenty of space to chomp their prey whole. Also, they have… well it’s basically like nose jelly and it allows them to sense electrical pulses of other animals in the water. This is probably also used to find prey.

We don’t know of any predators to coelacanths besides humans, though they apparently taste awful. They’re described as oily, which makes sense because instead of a spine they have what’s called a notochord that’s filled with an oily substance. They don’t have fully formed vertebrae either, but they’re still technically considered vertebrates. We’ve talked about some of the weird sort of “non-vertebrates” such as hagfish in the past, but coelacanths are of interest because they’re seen as a somewhat transitional species possibly showing the in between stages of watery animals and terrestrial animals.

Coelacanth fins aren’t like other fish fins, they’re more like our arms! When a coelacanth swims, its fins alternate in the same way a terrestrial animal walks with the opposite front and back limbs moving in unison. Here’s a video of Chester walking to show this in action. Now, don’t misunderstand. Sometimes coelacanths are titled a missing link between fish and terrestrial animals, however scientists are pretty certain that while they do seem to have traits akin to this alleged “missing link”, coelacanths are the end of a lineage that is otherwise now extinct - so no, they’re probably not your great great great fishy grandpa.

If all these strange features weren’t enough, coelacanths have one other unique trick up their… scales. Coelacanths give birth to live young. Now, the process of coelacanth mating has yet to be observed, but by studying specimens accidentally brought to the surface in fishing nets, we’ve been able to determine female coelacanths likely only reproduce with one male who fertilizes her eggs internally and she may have anywhere from five to more than twenty-five babies in a single litter. How long they can live is still unknown, though we can be certain they live at least twenty two years thanks to those identifying marks and the fact that coelacanths seem to be homebodies! Hmm… maybe they’re not so strange after all...

For more facts on coelacanths, check out the links in the description. Give a thumbs up if you learned something new today, and thank you for watching Animal Fact Files.