Phyllodesmium briareum (Bergh, 1896) 18mm
OPISTHOBRANCH OF THE WEEK
Opisthobranch of the Week Data
Frequency on Okinawa:
- Order: NUDIBRANCHIA
- Suborder: Aeolidacea
- Family: Facelinidae
[brackets indicate range for all Okinawa-collected specimens of the species]
- Individual Collection No: RFB #2437-B
- Location: Horseshoe Cliffs, Okinawa (26° 30.0'N, 127° 50.9'E) [Horseshoe Cliffs, Seragaki]
- Date: 26 July, 1990 [22 Apr '89, 19 Jan '90, 26 Jul '90, 28 Mar '93]
- Depth: 10ft (3m) [10ft, 20ft, 20ft, 30ft]
- Water temperature at collection depth: Not recorded
- Size: TL 18mm [18mm, 25mm, (2 indiv. not measured)]
- Specimen deposited: RFB Personal Research Collection (different individuals of the species deposited at Cal. Acad. Sci.)
Phyllodesmium briareum is considered to be common on Okinawa. Although I've only collected four specimens, many other individuals have been seen and photographed. I commonly find these attractive aeolids associated with the alcyonacean coral Pachyclavularia violacea, which is frequently seen in less than 10m here. The nudibranch very closely resembles the open polyps of the coral; sometimes the resemblance is so close that the polyps must be stimulated to retract in order to confirm the presence of the aeolids. I've counted as many as twelve of these attractive animals on a 30cm X 30cm patch of the host coral.
Rudman(1991) lists it as feeding on Alcyonaceans of the family Briareidae; Gosliner, Behrens, & Williams (1996) specifically point out that it feeds on Pachyclavularia violacea.
- Gosliner, T., Behrens, D.W., and Williams, G.C. 1996. Coral Reef Animals of the Indo-Pacific. Sea Challengers, Monterey, California.
- Rudman, W.B. 1991. Further studies on the taxonomy and biology of the octocoral-feeding genus Phyllodesmium Ehrenberg, 1831 (Nudibranchia: Aeolidoidea). Journal of Molluscan Studies, 57(2): 167-203.
Page Date: 03 Aug '98
Page Modification Date: 01 Mar '15
Digitally manipulated photo
Copyright © 2015 Robert F. Bolland