OKINAWAN
OPISTHOBRANCH OF THE WEEK
Gymnodoris inornata (Bergh, 1880) 60mm
Opisthobranch of the Week Data
Taxonomy:
- Order: NUDIBRANCHIA
- Suborder: Doridina
- Family: Gymnodorididae
Frequency on Okinawa:
- Rare on Okinawa's main island but common in the Keramas
Collection Data:
- Individual Collection No: RFB #3444-A
- Location: Tengan Pier, Okinawa (26° 24.0'N, 127° 51.1'E) [Seragaki, Tengan]
- Date: 9 July, 1995 [May '90(2); Feb '93; Jul '95]
- Depth: 40ft (12m) [5ft, 5ft, 40ft, 40ft]
- Water temperature at collection depth: 79°F (26°C)
- Size: TL 60mm [13mm, 26mm, 29mm, 60mm]
- Specimen deposited: RFB Personal Research Collection
[brackets indicate range for all Okinawa-collected specimens of the species]
Species Account:
Rudman (2001) comments in the Sea Slug Forum that Gymnodoris inornata ranges in color from translucent yellow to deep reddish orange and has slightly raised, darker colored pustules. The above featured animal has a delightful deep dark red color. The gills are numerous and short, and form a complete circle.
Leslie Chan (2001) has several remarkable photographs from Hong Kong posted on the Sea Slug Forum showing G. inornata feeding upon
Doriopsilla miniata and Dendrodoris fumata (several of the Chan animals are very similar in color to the above featured animal). In addition, Helen Hughes (1985) has an interesting account concerning the feeding by G. inornata in Hong Kong as well. Her studies were laboratory based and included a series of trials where individuals of were placed in tanks with potential prey species. Jun Imamoto & Nishina Masayoshi have a series of photographs of G. inornata featuring animals from mainland Japan and other Japanese sites, including the Keramas.
Gymnodoris inornata is considered to be rare in Okinawa's main island, however, in the Kerama Islands Group Atsushi Ono reports seeing over thirty individuals there (pers. comm.). I've collected four specimens from Okinawa's main island; I've also included A second page illustrating two additional individuals from the Keramas, including one with ova.
Literature Cited:
- Chan, L., 2001 (August 4). Gymnodoris inornata - feeding behaviour (1) [Message In] Sea Slug Forum. http://www.seaslugforum.net/find.cfm?id=4989 (also: http://www.seaslugforum.net/find.cfm?id=4991)
- Hughes, H. P. I. 1985. Feeding in Gymnodoris inornata (Bergh) and Gymnodoris alba (Bergh) (Opisthobranchia). In: Proceedings of the Second International Workshop on the Malacofauna of Hong Kong and southern China, Hong Kong, 1983. (Eds: Morton, B.; Dudgeon, D.) Hong Kong University Press, Hong Kong, 627-633. [publ. not seen by RFB]
- Imamoto & Nishina [In] Jun Imamoto & Nishina Masayoshi's Sea Slug Site. http://umiushi.zive.net/index.html
- Rudman, W. B., 2001 (July 31). Gymnodoris inornata Bergh, 1880.
[In] Sea Slug Forum. http://seaslugforum.net/gymninor.htm
Page Date: 29 Jul '02
Page Modification Date: 29 Jul '02
Digitally manipulated photo
Copyright © 2002 Robert F. Bolland