Chromodoris willani Rudman, 1982 (39mm)
OPISTHOBRANCH OF THE WEEK
Opisthobranch of the Week Data
Frequency on Okinawa:
- Order: NUDIBRANCHIA
- Suborder: Doridina
- Family: Chromodorididae
[brackets indicate range for all Okinawa-collected specimens of the species]
- Individual Collection No: RFB #2260-D
- Location: Seragaki (26° 30.4'N, 127° 52.6'E) [Channel Crevices, Horseshoe Cliffs, Seragaki]
- Date: 25 August, 1989 [May 84, Mar 87(2 indiv), May 89, Aug 89, Sep 89, Jun 90,
May 91, May 92, Aug 92, Dec 92]
- Depth: 170ft (51.8m) [70ft, 100ft, 110ft, 120ft, 140ft, 150ft, 150ft, 170ft,
170ft, 190ft, 220ft]
- Water temperature at collection depth: 79.7°F (26.5°C)
- Size: TL 39mm [7mm, 15mm, 16mm, 30mm, 38mm, 39mm, 40mm, 40mm, plus 3 indiv w/o
- Specimen deposited: Photo only, without specimen; different individuals of the species deposited at Cal Acad Sci).
Chromodoris willani is considered to be common on Okinawa, although I have collected only eleven specimens since May, 1984, many others have been seen and photographed. This is the most commonly observed deep water opisthobranch found here; I frequently see a half dozen or so during deep water excursions. These attractive animals are usually a distinctive blue color, but occasionally they are found as a silver form. The only other chromodorid found here in the Ryukyus Archipelago which is closely similar in appearance is Chromodoris lochi, but the distinctive tiny white opaque spots on both the gills and rhinophores of C. willani clearly distinguish the two from each other.
Chromodoris willani is commonly found between 130ft and 200ft (40 ~ 61m), usually amid coral rubble where it apparently feeds upon sponges.
Page Date: 02 Feb '98
Page Modification Date: 08 Apr '02
Digitally manipulated photo
Copyright © 2002 Robert F. Bolland