
The Coelacanth
Once known only from fossils, the coelacanth was thought to have gone extinct around 65 million years ago in the late cretaceous, during the great extinction.
Common Name | Scientific Name | Diet | Size | Depth | Ecosystem/Habitat | Zone |
---|---|---|---|---|---|---|
Coelacanth | Coelacanthiformes | Coelacanths eat fish, squid, and other cephalopods. | 6.5 feet (2 m) | 2,300 feet (700 m) | Steep rocky slopes and caves of volcanic islands. | Mesopelagic Zone |
The Coelacanth
Once known only from fossils, the coelacanth was thought to have gone extinct around 65 million years ago in the late cretaceous, during the great extinction that wiped out the dinosaurs. Fossils of these creatures dated from 80 to 360 million years ago, and yet in 1938, one was found off the coast of South Africa alive. A fish almost entirely unchanged since the days of dinosaurs.
This discovery represented one of the most significant natural history discoveries of recent times. Living at depths of around 200 metres, down in the Twilight Zone of the ocean, they are found around the steep rocky slopes of volcanic islands, venturing forth from their lava-rock caves at night to feed; being passive drift-feeders, they move slow and feed on cephalopods and smaller fish.
Believed by many to have no living relatives, the Coelecanth is a truly unique species. They are the only living vertebrates with a jointed skull, that swings upward to greatly increase the gape of the mouth. Their limb-like pectoral fins are also unique, as they are internally supported by bone, a feature not found in many other fish. They use them in a paddle-like fashion, as if they are walking through the water column.
These unusual features have led to the coelacanth’s evolutionary history becoming a matter of controversy; but most experts argue it is an early ancestor of modern day bony fish, with lungfishes being its closest relative. With fins so closely resembling limbs, coelacanths demonstrate the evolutionary pathway that saw animal life begin to dominate land.
The sight of these 2 metre long, 200 pound living fossils drifting in the deep is an ominous sight indeed. With only two known coelacanth populations in the world, both having been isolated for millions of years, their low numbers have led to a classification of critically endangered, and without careful management of human activities, this species could be lost forever, after having survived unchanged for millions of years.
Advertisement
CREATURE COLLECTIONS
Fish
With enlarged eyes, bioluminescent photophores, and often growing to enormous sizes, fish of the deep are oddly fascinating.
Invertebrates
The deeper you dive beneath the waves, the larger the invertebrates become. This demonstrates the phenomenon of deep sea gigantism.
Marine Mammals
Many mammals, from seals to the mighty cetaceans of the open seas, frequent the depths of the ocean, diving down in search of prey.
Reptiles
Though they may not dominate the seas as they once did, reptiles still play a vital part in the marine ecosystem, from turtles to sea snakes.
Sharks & Rays
The depths are home to some of the ocean's largest sharks, from Greenland sharks to Sixgills. As apex predators, they have a key role in the ecosystem.
ARTICLE COLLECTIONS
All
Read our in-depth write-ups about the environment, ecosystems, adaptations, and discoveries related to the deep sea. Individual animal profiles can be found by clicking 'fact files' in the menu above.
Exploration
Ah, the ocean. Rolling blue waves, picturesque seascapes, and a bottomless abyss of sheer darkness. With only 5% of the ocean having been discovered, there is much to explore.
Environment
Environmental degradation has reached even the isolated depths of the ocean, a realm we know little about, yet have caused much damage to with our destructive nature.
Ecosystems
We are only now beginning to understand the importance of deep sea ecosystems, from hydrothermal vents that mitigate climate change, to whale-falls that provide a large carbon sink.
Adaptations
To survive in the abyss, life has to overcome some extreme challenges. Thus, we find creatures with peculiar morphologies and astounding adaptations. Let's take a look.