OKINAWAN
OPISTHOBRANCH OF THE WEEK
Hydatina physis (Linnaeus, 1758) 61mm
Opisthobranch of the Week Data
Taxonomy:
- Order: CEPHALASPIDEA
- Family: Hydatinidae
Frequency on Okinawa:
Collection Data:
- Individual Collection No: RFB #3033
- Location: Horseshoe Cliffs (26o30.0'N, 127o50.9'E)
- Date: 15 July 1992 [May + Mar, 92; Mar, 93]
- Depth: 4ft (1.2m) [4~40ft]
- Water temperature at collection depth: Not recorded
- Size: TL 61mm [12, 27, 29, 61mm]
- Specimen deposited: Unknown disposition (photo only?)
[brackets indicate range for all Okinawa-collected specimens of the species]
Species Account:
Hydatina physis is considered to be uncommon on Okinawa; I have seen and collected a total of four living individuals, and I've collected eight "shell only" specimens (15~29mm) over a period of more than twenty years of diving here. Three of the living animals were collected from Horseshoe Cliffs (4~10ft) and one from Tengan Pier (40ft).
Copyright © 1999 Robert F. Bolland
Digitally manipulated photo
