First CT scan made of eggs inside coelacanth

by Mariko Kato

Researchers at Tokyo Institute of Technology carried out Wednesday what is believed to be the first CT scan of eggs inside a coelacanth, according to Norihiro Okada, a bioscience professor at the university and a member of the research team.

About 40 eggs were photographed inside each of the two coelacanths, which were captured off the coast of Tanzania, frozen and transported to Tokyo. The fish are 170 cm long and weigh 70 kg each, while their eggs are about 7 cm in diameter.

Coelacanths are thought to represent an early step in the evolution of fish to amphibians. The eggs hatch while still inside the female and the young grow to 30 cm in length before they emerge.

“I was surprised to see that all the eggs were the same size,” Okada was quoted by Kyodo News as saying. “I hope to do research into why this is.”

First appearing about 400 million years ago, coelacanths were thought to have gone extinct 335 million years later, around the same time as the dinosaurs. Since one was discovered in the Indian Ocean in 1938, others have turned up in waters off Indonesia, South Africa and elsewhere.

Coelacanths, which live at least 100 meters deep, have oily and foul-tasting flesh and lack commercial value as a food fish, but they are highly sought after by museums and private collectors.