Aspect: Tiny solitary polyp (although several can be present) with thin translucent tentacles atop a translucent jellyish stem attached to sponge surfaces. Population: Probably more common than it seems due to its very stealthy nature and small size (1cm). Notable feature: Comparatively large berry-like pink polyp head (gonophore, the gamete-producing organ), tentacle ends do not curl unlike those of other hydrozoans. Environment: Lives on sponges. Behaviour: Stings skin.
