Phyllidia willani Brunckhorst, 1993

Location: Horse Shoes, Okinawa Island (Onna and Yomitan area), Okinawa, Japan
Date: 2014/03/18
Length: 30mm
Depth: 15.0m
Water temperature: 23.0℃

Description

A phyllidiid 23–50 mm long, oval rather than elongate in shape. The dorsum bears a very pale lemon-yellow background with minute white pigment dots, giving an overall granular appearance. Four large tubercles are arranged as the corners of a diamond medially, each capped in pale yellow. Two longitudinal black swirls occur laterally on the dorsum, and small black patches may also be present. The rhinophores are gold with 16–18 lamellae. The hyponotum is pale and cross-hatched. The oral tentacles are long, cylindrical and pale cream-yellow.

Distribution

South China Sea, the Philippines and Papua New Guinea. Type locality: Anemone Reef, Madang, Papua New Guinea (11 m).

Etymology

Verbatim from the original description (Brunckhorst, 1993, p.41):

This species is named in honour of Dr R.C. Willan.

Remarks

Described as a new species in Brunckhorst, D.J. 1993 Records of the Australian Museum, Supplement 16: 1-107. The author noted in the Remarks that "Distinguishing features of Phyllidia willani include the pale granular background colouration, the two laterally positioned longitudinal black swirls, the four median notal tubercles, the pale coloured foot and oral tentacles, orange digestive gland mass, pale yellow rectum, and small fine penial spines" (p.40-41). Most similar to P. ocellata and P. babai, but distinguished by the pale granular yellow dorsum, four median tubercles arranged in a diamond, and two lateral black swirls.