Opisthobranch of the Week Data
I've not personally seen Pupa solidula here in the waters of Okinawa's main island and Atsushi Ono mentions (pers. comm.) seeing only the above single featured animal in the Keramas*. Atsushi dug the above featured animal from a sandy bottom environment in 10 meters. Atsushi mentions collecting the animal but unfortunately it was subsequently lost in the sediments of a home aquarium. Atsushi of course considers the species to be very rare in the Keramas.
Pupa solidula is considered to be cosmopolitan throughout the tropical Indo-West Pacific. The species is a sand burrower and is known to feed on polychete worms (Rudman, 1998). There are a pair of posterior flaps on the head, which form the "headshield" which gives the group the name "cephalaspid". This shield overlap the front of the shell and protects the mantle cavity from being obstructed with sand while the animal burrows through the substrate in search of prey.
* Keramas = the Kerama Islands Group, located 30 ~ 40 kilometers west of the Okinawa capitol, Naha.