DHI scientists rediscover a long-lost treasure: The Return of the Neptune’s Cup
It sounds like everybody’s dream. Finding a long-lost treasure at the bottom of the sea. That’s exactly what happened to DHI scientists earlier this year. On a routine survey dive, our marine biologists encountered a unique-looking sponge off Singapore’s southern islands. It was a specimen of a young Neptune’s Cup sponge, a species that was thought globally extinct for more than a century. The scientists now plan to study the sponge’s biology and ecology.
“When we came across the sponge, we knew immediately that this was something very different”, explains marine biologist Karenne Tun from DHI Singapore. “So we took pictures and a small sample which we handed over to a sponge exper”. Mr Lim Swee Cheng later identified the sponge as Ciiona patera, the Neptune’s Cup.
The rediscovery of the Neptune’s Cup is special in many ways: Neptune’s Cup sponge was first described from Singapore waters, in 1822. In its mature adult form, the sponge stands over one metre in height and half a meter in diameter. Records show that mature sponges were even used a bathtubs. However, the Neptune’s Cup vanished rapidly from Singaporean waters and was last sighted in 1870. It also seemed to have disappeared from other coastal waters and was last collected off Indonesia in 1908. This led many scientists to believe that the sponge had become extinct globally.
Since the 1990s, however, the Neptune’s Cup sponge started to reappear in dredge samples collected north of Australia. But no live specimens were ever recorded or observed underwater. As such, scientists could not study the biology and ecology of the sponge in its natural environment. Together with Singapore’s National Parks Board (NParks) and the National University of Singapore (NUS), DHI scientists now want to close this gap of knowledge.
“Basically, little is known about the Neptune’s Cup, as it was never found alive”, explains Karenne Tun. “Now we have the opportunity to study the biology and ecology of this impressive sponge and learn about its life cycle. It also showcases very well how DHI adds to the current body of knowledge. We’ve already had the first surprise: The Neptune’s Cup was thought to be a very slow growing species. However, between our last visits in April and August respectively, it had grown several centimetres. Looks like we might have to rethink some of these ideas.”