Hypselodoris bullocki (Collingwood, 1881) 36mm
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 #2955-D
- Location: Tengan Pier, Okinawa (26o24.0'N, 127o51.1'E) [Horseshoe, Onna Flats, Seragaki, Tengan]
- Date: 23 April, 1992 [Jul '86, Mar '87, Apr '87, Jun '87, May '89, Jun '90(2 indiv), Jul '91(2 indiv), Nov '91, Feb '92, Mar '92, Apr '92, May '92, Mar '93, Apr '93]
- Depth: 40ft (12m) [intertidal, 10ft(10 indiv), 15ft, 40ft, 140ft, 180ft, 190ft,]
- Water temperature at collection depth: Not recorded
- Size: 36mm [1 unrecorded, 7mm, 12mm, 15mm, 17mm, 18mm, 18mm, 19mm, 25mm, 25mm, 26mm, 28mm, 28mm, 30mm, 31mm, 36mm]
- Specimen deposited: California Academy of Sciences
Hypselodoris bullocki is one of the more strikingly attractive chromodorids occasionally seen on Okinawa. The animal was originally placed into the Genus Chromodoris by Collingwood but Rudman (1995) later transferred the animal to Hypselodoris.
Other than Noumea romeri, which looks similar to some color phases of H. bullocki as juveniles, there are no other described Okinawan dorids here which are apt to be confused with H. bullocki; the white, cream, or light pink-colored foot and notum (the notum is emarginated with a fine white line) in conjunction with the variably colored (most often orange on Okinawa specimens) rhinophores and gills give this animal immediate recognition status.
Hypselodoris bullocki is considered to be uncommon on Okinawa; the initial collection was made on 3 July, 1986 and the total collected animals number sixteen. Another half-dozen or so animals have been photographed but not collected.
The above featured animal is one of thirteen described species of Hypselodoris found in Okinawan waters. The thirteen species identified to date (July, 2011) are:
- Rudman, W.B. 1995. The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: further species from New Caledonia and the Noumea romeri colour group. Molluscan Research, 16: 1-43.
Page Date: 22 Feb '99
Page Modification Date: 18 Jul '11
Digitally manipulated photo
Copyright © 2011 Robert F. Bolland