Nemanthus nitidus is usually found with its base wrapped around the stalks of dead whip corals, usually at depths of 30m or more on the seaward slope. The columns are generally either solid orange or spotted with dark. The anemones are not large, usually with an oral disk less than 25mm in diameter (not including the tentacles). Sometimes we see the anemones crowded onto just the dead portion of a whip coral with the remaining coral still alive. We do not know if the expanding anemones (probably clones of the original settler on that coral) actively expand over and kill the coral as they take over the entire whip.
This one looks like a Nemanthus, but it was on some growth on the underside of a concrete barge scuttled as a marker on an Enewetak Atoll lagoon pinnacle.
We did not (yet) see these in the Marshalls, but in at least some areas, there is a well camouflaged shrimp that lives among the Nemanthus anemones on whip corals. We saw a pair of these shrimp, Izucaris masudai, at Ligpo, near Anilao, Philippines (photos below).
Created 28 July 2018
Updated 23 May 2023