News / Ibiza @en
“Jurassic Park of sponges” discovered in the Mediterranean Sea
Spanish researchers have discovered a ‘rock’ sponge reef unique in the world. The structure, of which its kind was thought to have been extinct millions of years ago, was discovered at a depth of 760 metres surrounding the top of a small seamount between Valencia and Ibiza. It was formed by the species Leiodermatium pfeifferae, a sponge that until now was only known in the Atlantic, from Macaronesia as far as the Caribbean, making it the first record of this species in the Mediterranean.
Silica reefs, built by sponges and not corals, were common in the Jurassic and Cretaceous seas but thought to have been extinct. To general surprise, in 1987, a live silica reef was discovered at a depth of 200 m in the Canadian Pacific coast, formed by hexactinellid sponges (‘glass sponges’). The reef that has now been discovered featuring the ‘rock’ sponges is an even rarer type of reef, since the vast majority of the ‘rock’ sponges species became extinct after the Cretaceous period. The relatively few species surviving today are confined to tropical and temperate deep waters and were thought to have lost their ability to form reef-like aggregations.
The sponge aggregations which reach almost a metre and a half in height were found using a submarine robot aboard the Oceana Ranger which enabled the filming and collection of information on species associated with this ecosystem, such as other sponges, corals, gorgonians, deep-sea crabs, conger eels, amongst others.
© Photo: Oceana.