young, 4 mm
with egg masses
Glossodoris rufomarginata (Bergh, 1890)
|Maximum size: 25 mm.
has a white body covered with minute
flecks giving it the overall appearance of a brown animal. The margin
is white, edged with a fine orange or tan line in most individuals. The
mantle margin becomes more elaborately folded with increasing age. The
rhinophores and gills are light brown, lined with white.
rufomarginata is one of the most commonly encountered diurnal
nudibranchs from < 1 to 64 m (< 3 to 210 ft). It is
on rocky bottoms in protected to highly exposed
locations and is particularly common on shaded cliffs. It also
occasionally occurs in tide pools. Several animals are often found together
on a dark gray sponge, Cacospongia
sp., on which it feeds.
(Note 1) Its egg masses are white and usually composed of about two whorls. They
are typically laid on or near the host sponge.
Big Island, Maui, Lanai, Molokai, Oahu, Kauai, Niihau, French Frigate Shoals and Gardner Pinnacles: widely
distributed in the Indo-Pacific.
listed as Chromodoris
youngbleuthi in Kay, 1979 and Kay & Young, 1969. It is also listed as Chromolaichma youngbleuthi (Kay
& Young, 1969) in Bertsch & Johnson, 1981. The name means "red
margin." It's referred to as the "white-margin nudibranch" in
Hoover, 1998 & 2006 as well as the "whitemargin sea slug" in Hoover, 1997. It was first reported in Hawaii from Hanauma
Bay, Oahu, in May, 1965 (Kay & Young, 1969).
Roberts: Makena, Maui; 2007.
Observations and comments:
1: The sponge may appear cream when the dusky surface has been eaten away by the nudibranchs.