lemon yellow nudibranch with black-edged ruffles has twitchy gills!
On rubble near reefs. Commonly encountered on many of our Southern
shores, sometimes in rather large numbers. It was previously known
as Glossodoris atromarginata.
Features: 3-5cm long. A hard lemon-yellow
body with an ruffled margin that is elegantly edged in black. It holds
this portion of its body raised. The black edging is also found on
the feathery gills and feathery rhinopores. There are black rings
where the rhinophores emerge from the body.
The feathery gills rotate constantly to and fro. This is believed
to help improve respiration as unlike most other nudibranchs which
have thin body skins; the body skin of this nudibranch is rather thick
and probably doesn't allow much secondary respiration to take place
across the body skin.
There are some other Glossodoris nudibranchs that look similar
to it and can only be differentiated by internal examination.
What does it eat? It eats sponges.
Neville Coleman notes it eating these sponges: Fasciospongia
sp., Spongia sp. and Luffariella sp.
Members of the Family Chromodorididae absorb the toxic chemicals in
their sponge food and incorporate these chemicals into the mantle
glands on their backs which act to repel predators.
Body held raised
St. John's Island, May 05
Sisters Island, Jul 06
Closeup of mouth and short oral tentacles.
Feathery gills rotate constantly
A mating mess?
Pulau Semakau, Nov 09
nudibranchs on Singapore shores
- Tan Siong
Kiat and Henrietta P. M. Woo, 2010 Preliminary
Checklist of The Molluscs of Singapore (pdf), Raffles
Museum of Biodiversity Research, National University of Singapore.
- Chou, L.
M., 1998. A
Guide to the Coral Reef Life of Singapore. Singapore Science
Centre. 128 pages.
Helmut, 2001. Nudibranchs
and Sea Snails: Indo-Pacific Field Guide
IKAN-Unterwasserachiv, Frankfurt. 321 pp.
Neville, 1989. Nudibranchs
of the South Pacific Vol 1. 64 pp.
Neville. 2001. 1001
Nudibranchs: Catalogue of Indo-Pacific Sea Slugs. Neville
Coleman’s Underwater Geographic Pty Ltd, Australia.144pp.
- Humann, Paul
and Ned Deloach. 2010. Reef
Creature Identification: Tropical Pacific New World Publications.
- Wells, Fred
E. and Clayton W. Bryce. 2000. Slugs
of Western Australia: A guide to the species from the Indian to
West Pacific Oceans.
Western Australian Museum. 184 pp.
Terrence M., David W. Behrens and Gary C. Williams. 1996. Coral
Reef Animals of the Indo-Pacific: Animal life from Africa to Hawai’I
exclusive of the vertebrates
Sea Challengers. 314pp.