What is a coelacanth?

By Helen Pilcher

Published: Sunday, 16 October 2022 at 12:00 am

For years, scientists thought it died out with the dinosaurs. The only known coelacanths were fossils. Then in 1938, a South African museum curator found a dead one in a fisherman’s catch. Live specimens were later caught, proving that this curious fish was never actually extinct.

""
The well-preserved Coelacanth fossil displayed on a limestone slab © Alamy

Living deep in the waters around Africa’s Comoro Islands and Indonesia’s Sulawesi, this big, bottom-dweller is unlike any other living fish.

Weird True Fact 1: it has eight fins, including two pairs which stick out from the body like legs. It doesn’t use them for walking though. They’re more like the stabilisers you get on kids’ bikes.

WTF 2: instead of a bony backbone, coelacanths have a hollow, oil-filled tube called a notochord.

WTF 3: they are fatheads. The brain occupies just 1.5 per cent of its braincase and the rest is filled with fat.

It also has thick scales, a unique jaw joint, a huge gape, and an organ in the snout for electroreception. By detecting electrostatic fields, they can use this intel to avoid obstacles and detect prey.