Hypselodoris pulchella is a long slender species with a body size up to 80 mm or even 110 mm. The mantleedges are well extended along the body, with a thin bluishborder. The mantle and the foot are creamy white, covered with numerous small rounded yellowish-orange spots of different sizes. There is always a diffusepattern of pale violet-brown on the back; this is absent in the similar species Hypselodoris ghardaqana. The sensory tentacles are bluish. The main respiratory organs vary from bluish to orange. These sea slugs usually raise and lower rhythmically their head, vibrating their gills. They often show a characteristic 'trailing' behaviour, with two individuals following closely each other. This species feeds on sponges.