OKINAWAN
OPISTHOBRANCH OF THE WEEK
Scyllaea pelagica (Linnaeus, 1758) 20mm
Photo by Atsushi Ono
Opisthobranch of the Week Data
Taxonomy:
- Order: NUDIBRANCHIA
- Suborder: Dendronotina
- Family: Scyllaeidae
Frequency on Okinawa:
Collection Data:
- Individual Collection No: Atsushi Ono #O-598
- Location: Zamami Island, Kerama Islands, Okinawa
- Date: 30 August, 2001
- Depth: On floating algae at water's surface
- Water temperature at collection depth: ca. 84oF (ca. 29oC)
- Size: TL 20mm [only a single collected specimen]
- Specimen deposited: California Academy of Sciences
- Specimen deposited: Kominato Marine Laboratory, Marine Biosystems Research Center, Chiba University, Japan
[brackets indicate range for all Okinawa-collected specimens of the species]
Species Account:
I've not personally seen Scyllaea pelagica here in the waters of Okinawa's main island. Atsushi Ono mentions seeing an excess of twenty animals at the time the above photo was taken off Zamami Island in the Keramas
* and also that he has seen many individuals during February of 2005 (pers. comm.) and considers the species to be common there. Atsushi reports finding the above featured animal at the surface on floating algae.
Scyllaea pelagica has a worldwide distribution, living a pelagic existence attached to pieces of floating kelp (commonly on Sargassum species), where it feed on attached hydroids. This attractive scyllaeid is quite variable in color and Bill Rudman has numerous images posted on the Sea Slug Forum illustrating some of this color variation. Additionally, Mike Miller has a beautiful green animal featured on his page as well.
I've previously featured two similar appearing members of the family on these pages, Crosslandia viridis and
Notobryon wardi.
Etymology:
- The species name reflects its pelagic existence, drifting on open water in association with floating algae.
Literature Cited:
- Miller, Mike. 2002 (February 8). Scyllaea pelagica. [In] The Slug Site. Available from: http://slugsite.us/bow/nudwk299.htm
- Rudman, W.B., 2004 (March 10). Scyllaea pelagica Linnaeus, 1758. [In] Sea Slug Forum. Australian Museum, Sydney. Available from:
http://www.seaslugforum.net/factsheet.cfm?base=scylpel
* 
Keramas = the Kerama Islands Group, located 30 ~ 40 kilometers west of the Okinawa capitol, Naha.
Page Date: 21 Feb '05
Page Modification Date: 21 Feb '05
Digitally manipulated photo (image has been horizontally flipped)
Copyright © 2005 Robert F. Bolland
