New Scientist said:
We thought they died out 400 million years ago till one popped up off the coast of the Comoros Islands in 1938. Their two unusual front fins show they are closely related to the first fish to clamber onto land around 400 million years ago. Now, coelacanths, dubbed "living fossils" since their unexpected reappearance, have sprung another surprise: they are serial monogamists.
Coelacanths are enormous, bottom-dwelling fish that lurk between 100 and 200 metres beneath the surface, on the rocky sides of volcanic islands in the Indian Ocean. The 1.5-metre-long giants are best known from sightings in the Comoros Islands, but have also been spotted off the eastern and south-eastern coasts of Africa. They spend their days in cavities inside submarine volcanic rocks, and only venture out at night to feed – mostly on squid, octopus, cuttlefish and other fish.
"We know hardly anything about their reproduction," says Kathrin Lampert of Ruhr University Bochum in Germany. What is known is that their gestation period is an impressive three years and they bear live young.