Halgerda willeyi

Widespread across tropical Indo-West Pacific.

Rigid domed body with ridges creating tubercles where the ridges meet. The mantle edge is white with black lines blending into brown with orange lines. This describes the colours of my individual but there is a large variation. The gills are exposed and consist of two primary plumes than split into branches. They are white at the base and have brown stripes or dots. The rhinophores are also brown and white - perfoliate. Both gills and rhinophores are fully retractable.