Among many different types of symbiotic relationships in the natural world, especially prevalent in the marine environment, corals prove to us once again that they are the symbiosis all-around champions!
A team of Japanese biologists reported for the first time a peculiar symbiotic ecology between a sea anemone and a homoscleromorph sponge. The new species, Tempuractis rinkai gen. et sp. nov. assigned to family Edwardsiidae, was discovered in several localities along the rocky shores of shallow intertidal habitats off Japanese coasts. It is approximately 4 mm in size and has a peculiar morphology compared to other known species of the same family. However, this new sea anemone resembles some genera, especially Nematostella, a well-known model for developmental and molecular studies.
In the field, T. rinkai sp. nov. is always found living inside homoscleromorph sponge of the genus Oscarella, which suggests an obligate symbiosis with this Porifera. The benefit of this symbiosis is discussed on the basis of observations of live specimens, both in the aquarium and field, the sea anemone hiding its unprotected body while the nematocysts of its tentacles dissuade sponge’s predators.
Takato Izumi, Yuji Ise, Kensuke Yanagi, Daisuke Shibata, Rei Ueshima. First Detailed Record of Symbiosis Between a Sea Anemone and Homoscleromorph Sponge, With a Description of Tempuractis rinkai gen. et sp. nov. (Cnidaria: Anthozoa: Actiniaria: Edwardsiidae). Zoological Science 2018, 35:188-198.