It is thought that the differences in the shape of tentacles between Euphyllia species may be related to specialised feeding habits (2). These tentacles, unlike many other corals, do not possess clusters of stinging cells, and so may be adapted to capture food particles using water and cilia (microscopic hair-like projections), (2). Euphyllia corals also possess specialised tentacles that extend further than the normal feeding tentacles. These ‘sweeper tentacles’, can extend up to eight inches further than the normal tentacles and have numerous powerful stinging cells (nematocysts), that can cause significant localised damage to other corals that are growing nearby (4). On reefs where there is fierce competition for space, this is an extremely good defensive adaptation to possess.
Euphyllia corals have separate male and female colonies (not all corals do), and most release eggs and sperm for external fertilization in the water, which then form larvae. In equatorial localities however, some may brood larvae internally (2). In captivity, asexual reproduction is much more common (4).