Hey guys! Welcome back to the channel in today's video i'm going to be talking about a really
special fish called the coelacanth now these fish really fascinate me because they basically went
missing for about 70 million years which yeah that's a really long time to lose something
so yeah now you're probably wondering how the hell do you lose something for that long let me explain
so coelacanths are deep water fish and they're originally known only to the scientific community
through fossils and the oldest of those fossils dated as far back as 360 million years ago so
they're pretty old pretty old fish we can say the more recent fossils dated to around
80 million years ago now if anyone's watching who's kind of into their evolutionary slash
geological history you'll probably notice that this coincided with a very
big major world event and that is the mass extinction that killed off the dinosaurs
so yes scientists basically unanimously agreed that the stellar cats must have gone extinct
during this mass extinction event and that was it they were gone dead buried
never to be seen again okay yeah by now you've probably guessed where the story's going
they weren't actually dead so in 1938 a south african museum curator called
marjorie courtney latimer was basically having a stroll down by her local harbour
and she spotted this prehistoric looking fish among the catch of a local fishing trawler so
at that point marjorie probably thought this isn't really like any fish i've seen before so she took
it to a local fish expert who did confirm that it was a coelacanth but it wasn't till around 14
years later when another specimen was discovered and this time it was in the camaro islands
now speaking to the local fishermen they did determine that they did haul up coelacanths around
one to two times a year but because they weren't really tasty and couldn't really be used for much
they weren't really highly valued among the locals however to the scientific community the discovery
was huge i mean really really big kind of as exciting as someone discovering a living species
of velociraptor in their backyard which okay yeah might be scary for the person who discovers it but
it would be pretty cool so coelacanths are known as living fossils because although they
are very much distinct from their ancestors that were found in fossils they do still have
very similar appearances now there are actually currently two known species of coelacanth which
are alive today so for almost 60 years they were known only from individuals that were found in
the western indian ocean mainly around the komoro islands but in 1997 an individual was discovered
in indonesia and it was around the island of suluwezi now the seal accounts from these two
locations did look remarkably similar so it was very much presumed that they were all one species
that was until scientists analyzed their dna and found that these two coelacanths had actually
separated a few million years ago and that was probably due to currents and so the geology of
the seabed which caused them to be kept apart and then evolved separately so there is a lot
of discussion in the scientific community about where coelacanths fit within evolution
but many scientists believe that the coelacanths do represent an early step in the evolution of
tetrapods so could actually be related to early ancestors of other forelimbed animals such as
birds mammals and amphibians succeeded cats are really fascinating and also really mysterious
animals as well so they're found in deep sea canyons in what's known as the twilight zone
and this is usually a depth of around 150 meters but individuals have been known to go as far as
700 meters below the surface so really deep and this is why they've probably been unknown to the
scientific community for so long because at those kind of depths you'd need either a re-breather
of submersible to be able to actually see them so it's no surprise that they've kind of been hidden
away in the depths in secret for for such a long time now because they've only been rediscovered
relatively recently and very few specimens have actually been found in that time very little is
understood about the coelocants they're really really poorly known and very little is understood
about their ecology and biology previous studies have suggested that coelacanths live to around 20
years old probably absolute max but a study that came out really recently actually suggested that
they could live up to around 100 years old which would make coelacanths one of the oldest living
fish alive today it was really amazing how they did this research has basically counted these
calcium ring-like structures on the scales of the coelacants and one of these rings forms around
every year so they're able to determine the age by counting these rings in a similar way to how
we determine the age of trees by counting the tree rings and they also found that coelacanths don't
reach sexual maturity until around 50 years old which is kind of like us reaching puberty well
into middle ages and pregnancy and coelacanths also last for five years now i don't even want to
imagine a five year pregnancy so this means that coelacanths have one of the slowest life histories
of all fish species now this is actually really bad news for the coelacanths because they are
both living species threatened with extinction and this could be why coelacanths are so rarely
seen because they take so long to mature because they have such a long gestation period and have
very few offspring it means the population can't really recover if a lot of them are killed off
while they're young so as a result this would make them extremely vulnerable to any changes
in their environment and overfishing as well if too many young coelacanths are being captured
so there we go that is the sealer can i'm sure you'll agree they are really really fascinating
fish and i think the thing i really love most about this story is it really highlights just how
little we still know about our oceans and how much there really is still left to discover
so thank you so much for watching this video i really hope you enjoyed it and you loved
learning all about coelacanths if you want to see more wildlife related videos be sure to hit
the subscribe button and you can also follow me on other social medias as well where i regularly
talk about all things wildlife so with that said i will see you in the next video bye guys
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