Facelina bilineata
Hirano in Hirano & Ito, 1998
Order: NUDIBRANCHIA
Suborder: AEOLIDINA
Family: Glaucidae
DISTRIBUTION
Japan
PHOTO
Closeup of head on upper left showing characteristic 2 lines which give it is name. Compare with photo on lower right of Facelina quadrilineata with 4 lines. PHOTOS: Yoshi Hirano.
One distinguishing feature of this species is the pair of brown to bright orange-red lines on the head.
It has been found during most of the year at Kominato, Boso Peninsula, Honshu Island, from the low intertidal to shallow sublittoral. It is often found in close association with the athecate hydroid Eudendrium sp., but in laboratory feeding experiments at least 6 other species of hydroids were ingested as well - Hirano & Ito, 1998.
Refer to the page on Facelina quadrilineata for a discussion of anatomical differences, and see the page comparing the development of the two very similarly coloured sympatric species Facelina bilineata and Facelina quadrilineata.
References:
• Ito, M. & Hirano, Y. (1996) the spawn and embryonic development of two colour morphs of the aeolid nudibranch Facelinella quadrilineata(Baba, 1930). Venus, 55(2): 115-121.
• Hirano, Y.J. & Ito, M. (1998). 'Facelinella quadrilineata' (Baba, 1930), a pair of cryptic species of Facelina from Japan. Zoological Science, 15: 791-797.
Rudman, W.B., 1999 (June 26) Facelina bilineata Hirano in Hirano & Ito, 1998. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/facebile
Related messages
Facelina bilineata from Japan
May 16, 2002
From: Nishina Masayoshi
Dear Bill,
THanks for your earlier comments. I suspect that this is also Facelina bilineata Hirano in Hirano & Ito, 1998.
Date: 3 May,2002
Location: Echizen coast, Japan
Length: 10mm
Depth: 4m
Photo by N.Chikako
Best Regards,
Nishina Masayoshi
nishina@wips.co.jp
Dear Nishina,
Thanks for these photos which show an even stronger colour pattern than in your previous photos.
Best wishes,
Bill Rudman
Facelina bilineata from Hachijo Is., Japan
May 15, 2002
From: Nishina Masayoshi
Dear Bill,
When I turned over a stone, I found this animal. I suspect this animal belong to Phidiana. The rhinophores have edged annuli like a screw. I suspect the orange sponge is the food for the animal.
Date:2002 April 21
Location: Hachijo Island Japan
Depth: 6m
Length: 10mm
Photo by N.Chikako
Best Regards,
Nishina Masayoshi
http://umiushi.zive.net/index.html
nishina@wips.co.jp
Dear Nishina,
This is Facelina bilineata. Your animal looks almost identical to the colour painting published by Baba (1935) of an animal from Mutsu Bay that he considered to be a variety of his Cuthona (Hervia) quadrilineata (Baba, 1930) [= Facelina quadrilineata]. It is only very recently that Hirano & Ito (1998) have shown that this is a distinct species. Have a look at the page comparing the development of these two very similarly coloured sympatric species -Facelina bilineata and Facelina quadrilineata.
The characteristic colour lines of this species can range from this bright orange to a quite dull brown.
• Baba,K (1935): Report on the biological survey of Mutsu Bay (27). Nudibranchia of Mutsu Bay. Science Reports of the Tohoku Imperial University, series 4, Biology 10(2, August), 331-360. (Pls.5-7)
• Hirano, Y.J. & Ito, M. (1998). 'Facelinella quadrilineata' (Baba, 1930), a pair of cryptic species of Facelina from Japan. Zoological Science, 15: 791-797.
