Thuridilla vatae (Risbec, 1928) 3mm
OPISTHOBRANCH OF THE WEEK
Opisthobranch of the Week Data
Frequency on Okinawa:
- Order: SACOGLOSSA
- Family: Elysiidae
[brackets indicate range for all Okinawa-collected specimens of the species]
- Individual Collection No: RFB #2656-D
- Location: Horseshoe Cliffs, Okinawa (26° 30.0'N, 127° 50.9'E) [Horseshoe, Seragaki]
- Date: 1 August, 1991 [16 Jul '89, 9 Jun '91, 26 Jul '91, 1 Aug '91, 12 May '00]
- Depth: 10ft (3m) [4ft, 10ft, 10ft, 10ft, 10ft]
- Water temperature at collection depth: Not recorded
- Size: TL 3mm [3mm, 6mm, unrecorded size (ca. 10mm), 11mm, 19mm]
- Specimen deposited: RFB Personal Research Collection (different individual of the
species deposited at Cal Acad Sci)
Thuridilla vatae is considered to be uncommon in the waters of Okinawa's main island; I've collected only five specimens, but I've certainly seen others which were neither photographed nor collected. I've included a second 19mm individual of the species, showing a bit of variation from that of the featured animal above. Ono (1999) reports T. vatae being found in the Kerama Islands Group as well.
The following description concerning the external morphology of Thuridilla vatae is taken from Gosliner (1995):
The body is dark bluish with scattered black and yellow spots. The margin of the parapodia is cream to yellow, but this pigment does not form a distinct band as in other members of the genus. The head is the same color as the body with a y-shaped yellowish or white marking that extends onto most of the length of the rhinophores. The apex of the rhinophores is bright red. The anterior margin of the foot is the same color as the remainder of the body.
- Gosliner, T.M. 1995. The Genus Thuridilla (Opisthobranchia: Elysiidae) from the Tropical Indo-Pacific, with a Revision of the Phylogeny and Systematics of the Elysiidae. Proc. Cal. Acad. Sci. 49(1): 1-54.
- Ono, A. 1999. Opisthobranchs of Kerama Islands, TBS-BRITANNICA & Co., Ltd., Japan. 184pp.
Page Date: 18 Feb '02
Page Modification Date: 18 Feb '02
Digitally manipulated photo
Copyright © 2002 Robert F. Bolland