Despite being crucial for habitat provision and being able to inhabit most oceans and all depths, documentation of threats affecting antipatharian corals (known as black corals) is very limited. We provide the second report of sea anemones in the genus Nemanthus overgrowing antipatharian corals causing the death of either entire colonies or sections of them. Our observations are from shallow and mesophotic reefs at the epicentre of marine biodiversity in Indonesia. Other instances exist where Nemanthus sp., as well as various species of zoanthids, have been reported to be in ‘association’ with antipatharians from other regions, which suggests that this could be a widespread threat to antipatharians. It is urgent to investigate the causes and to document the long-term effects that the sea anemones and zoanthids are having, in order to understand how this phenomenon will affect antipatharian populations and the fauna they support.
SCUBA (open-circuit or unspecified)