Felimare picta is one of the nudibranch sea slugs (shell-less gastropods with external gills) found offshore along Sanibel Island and other parts of Southwest Florida. Reaching 13 cm (about 5.1 inches), it is one of the largest nudibranch species in the western Atlantic Ocean.
It is also one of the most attractive, showing an elegant color pattern of yellow lines and elliptical markings against a dark blue, sometimes almost black, background. The gills are visible as a set of feather-like projections on the back of the animal.
The egg mass in this species is orange, measuring about 25 mm (about an inch). Microscopic eggs form a gossamer-like structure, embedded in a gelatinous support matrix. The photos were taken in the “Children’s Learning Lab,” which contained the first aquarium at the National Shell Museum.