Coelacanth
A fish science declared extinct for 66 million years — found alive in 1938 by a museum curator who noticed something odd in a fishing catch
No photo available for Coelacanth
Superpower
The coelacanth has fleshy, lobe-shaped fins with an internal bony structure — limb precursors, not fins in the conventional sense — that move in an alternating pattern matching the gait of four-limbed land animals. It also has a unique intracranial joint that allows the front of the skull to swing upward while feeding, creating an enormous gape. It is the most intact biological link between fish and the first land vertebrates ever found alive.
Overview
Latimeria chalumnae was known only from fossils when South African museum curator Marjorie Courtenay-Latimer noticed something strange in a fisherman's catch on December 23, 1938. The coelacanth was supposed to have been extinct since the end of the Cretaceous — 66 million years ago. It hadn't been. A second species was discovered in Indonesia in 1997, thousands of miles away. The coelacanth is the most famous 'Lazarus taxon' — a species that appeared to vanish from the fossil record and turned out to still exist.
Found in
Deep rocky reef slopes of the Comoro Islands, Madagascar, and the East African coast at depths of 150–700m. A separate species (Latimeria menadoensis) lives in the Sulawesi Sea, Indonesia. Both populations are extremely small.
Things worth knowing
- 1
Coelacanths give birth to live young after a gestation period of over a year — one of the longest of any fish. The pups are born fully formed and immediately independent.
- 2
The coelacanth's brain fills only 1.5% of its braincase — the rest is fat. They evolved a brain size sufficient for their needs hundreds of millions of years before the surrounding space was available.
- 3
Coelacanths have electroreceptive organs in their snouts that detect the electrical fields of prey in the darkness of deep reef crevices — the same sensory system that predates most vertebrate groups by hundreds of millions of years.
- 4
Coelacanth scales (cosmoid scales) have not been used by any other animal for approximately 300 million years. Each has a layered structure with enamel-like material on top — a design found in fossil fish long before anything resembling a modern fish existed.
- 5
All known coelacanth populations are tiny and critically threatened. The entire East African population is estimated at fewer than 500 individuals — a species that survived five mass extinctions is now endangered primarily by bycatch in deep-set gillnets.