young, 1.8 mm
on food sponge
Rostanga(?) sp. #3
|Maximum size: 21 mm.
a moderately soft, papillate species that ranges from pale
cream to orange. Dark pigment forms leopard-like spots on the notum but
varies in intensity. The notum and
rachis are variably flecked with white and one to four white patches
may be present on the sides of the notum. (Note 1) The rhinophores have
Rostanga(?) sp. #3 is
a common dorid found in the low intertidal at protected to moderately
exposed locations. Occasionally, it may also be found subtidally to
depths of 1 m (3 ft). Large animals sometimes "vibrate" their
rhinophores rhythmically while crawling. It feeds on a peach-colored
encrusting sponge and lays an orange egg mass with a variably ruffled
edge. The eggs hatch in about six days in the laboratory.
Maui, Oahu and Kauai: probably known from Japan.
to be the species listed as Thordisa
hilaris Bergh, 1905 in Kay, 1979, Kay & Young, 1969 and Bertsch & Johnson, 1981.
It was first reported in Hawaii from Fort Kamehameha, Oahu in July,
(Kay & Young, 1969). It may ultimately turn out to be something other than a Rostanga sp.
Photo: CP: 21
mm; Hekili Point, Maui; Nov. 7, 2006.
Observations and comments:
1: We've observed animals with and
without obvious spotting paired with each other in the field. Of
particular note was a pair observed on Oct. 8, 2010 at Hekili Point.
One of the animals was light tan with lateral white patches and obvious
dark flecks. The other was larger, dark yellow-orange and without
lateral white spots or obvious dark flecks. The latter animal was
visibly vibrating it's rhinophores while the former wasn't. Both were
resting near a typical egg mass.