Sagaminopteron nigropunctatum Carlson & Hoff, 1973
Sagaminopteron nigropunctatum was originally described from Guam, Mariana Islands. The species has since been found in many other areas of the Western Pacific as well as the Indian Ocean. Adult animals average about 9mm in length though specimens up to 16mm have been found. S. nigropunctatum is commonly associated with a gray sponge,Dysidea granulosa and on occasion can be found on Dysidea herbacea. The animals are difficult to see on their sponge host since their color and texture match that of the sponge.
The above photo is a 8mm Sagaminopteron nigropunctatum with egg masses from Palau. It was collected 24 Sept '96 at a depth of 13m; 'Wonder Channel', Palau. The host sponge in this case is Dysidea herbacea.
Sagaminopteron is a genus in the family Gastropteridae in the
Opisthobranch subclass Cephalaspidea. Further information on the
Gastropteridae can be found in a paper by Dr. Terry Gosliner (1989) in The
Species of Sagaminopteron (The genus is named for Sagami
Bay, Japan, where Emperor Hirohito collected so many
opisthobranchs that have been studied by Kikutaro Baba) are
all found on sponges, upon which they feed. The feeding
biology of other members of the family is virtually unknown.