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Ornate
leaf slug
Elysia ornata
Family Plakobranchidae
updated
Oct 2019
Where
seen? Often mistaken for leafy seaweed, this slug is seen on all our shores.
However, it appears to be seasonal. Sometimes seen in large numbers,
at other times, none is to be seen.
Features: 4-6cm. Body long with
a pair of very large 'wings' (called parapodia). The overall body
colour of the slug may be shades of green, yellow or even white. It
is believed that the colour depends on how much and what seaweed is
in the animal's digestive system. But all have a black margin on the
edge of the parapodia, with an orange or yellow margin next to the
black. There is a pair of long thick tentacles with tips in the same
colour banding as the body edge. The body may have black spots. It
may also have white spots, which are glands that secrete a white substance
that may repel predators. The parapodia are often held in ruffles
so that the animal resembles seaweed.
What does it eat? This slug is
believed to eat the Hairy
green seaweed (Bryopsis sp.) Indeed, leaf slugs are commonly
seen there is a bloom of this green feathery seaweed on the shores.
See details in the Family Elysiidae for
more about how the slug eats and uses the seaweed's chloroplasts. |
St. John's Island, Jun 07 |
Pulau Sekudu, Apr 06 |
Sentosa, Jan 05 |
Baby Sacoglossa: These slugs are
simultaneous hermaphrodites, that is, each animal has both male and
female reproductive organs at the same time. They practice internal
fertilisation. When two slugs mate, they may both act as males, extending
the penis (usually a white tube that emerges from the side of the
neck). Some may insert the penis into the female genital pore, others
may simply pierce the partner anywhere in the body. They lay eggs
in ribbons. |
Mating slugs
St. John's Island, May 05
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The white bits are the reproductive organs.
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Also seen among Sargassum seaweeds.
St John's Island, Oct 11
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Sentosa, Apr 04
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Just mated?
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Recently laid egg strings?
Pulau Jong, Jan 23
Photo shared by Lok Kok Sheng on facebook. |
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Ornate
leaf slugs on Singapore shores |
Other sightings on Singapore shores |
Punggol, May 21
Photo shared by Richard Kuah on facebook. |
Changi, May 11
Photo shared by Loh Kok Sheng on his
blog. |
Chang Lost Coast, Jun 22
Photo shared by Loh Kok Sheng on facebook. |
East Coast, May 08
Photo shared by Loh Kok Sheng on his
blog. |
East Coast, NSRCC, Nov 20
Photo shared by James Koh on flickr. |
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Tuas, Mar 15
Photo shared by Marcus Ng on facebook. |
Labrador, Dec 06
Photo shared by Wai on her
blog. |
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Lazarus Island, Nov 20
Photo shared by Jianlin Liu on facebook. |
Lazarus Island, Feb 11
Photo shared by Loh Kok Sheng on flickr. |
Terumbu Selegie, May 24
Photo shared by Loh Kok Sheng on facebook. |
Cyrene Reef, Nov 09
Photo shared by James Koh on flickr. |
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Pulau
Jong, Apr 11
Photo
shared by Toh Chay Hoon on her
blog. |
Terumbu Selegie, Jun 11
Photo shared by Neo Mei Lin on her
blog. |
Pulau
Hantu, Apr 21
Photo
shared by Richard Kuah on facebook. |
Pulau Semakau, Aug 14
Photo shared by Loh Kok Sheng on his
blog. |
Beting Bemban Besar, Mar 17
Photo shared by Richard Kuah on facebook. |
Terumbu Raya, Feb 14
Photo shared by Russel Low on facebook. |
Terumbu Bemban, May 21
Photo shared by Toh Chay Hoon on facebook. |
Terumbu Pempang Laut, Mar 24
Photo shared by Tommy Arden on facebook. |
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Raffles Lighthouse, Nov 16
Photo shared by Jianlin Liu on facebook. |
Pulau Pawai, Dec 09
Photo shared by Loh Kok Sheng on his
flickr. |
Pulau Salu, Apr 21
Photo shared by Loh Kok Sheng on facebook. |
Pulau Sudong, Dec 09
Photo shared by Toh Chay Hoon on her
flickr. |
Pulau Biola, Dec 09 |
Pulau Biola, May 10 |
Links
References
- K. R. Jensen. Sacoglossa (Mollusca: Gastropoda: Heterobranchia) from northern coasts of Singapore. 10 July 2015. The Comprehensive Marine Biodiversity Survey: Johor Straits International Workshop (2012) The Raffles Bulletin of Zoology 2015 Supplement No. 31, Pp. 226-249.
- 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.
- Kathe
R. Jensen. 30 Dec 2009. Sacoglossa
(Mollusca: Gastropoda: Opisthobranchia) from Singapore. The Raffles Bulletin of Zoology, Supplement 22: 207-223.
- Chou, L.
M., 1998. A
Guide to the Coral Reef Life of Singapore. Singapore Science
Centre. 128 pages.
- Debelius,
Helmut, 2001. Nudibranchs
and Sea Snails: Indo-Pacific Field Guide IKAN-Unterwasserachiv, Frankfurt. 321 pp.
- 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.
- Coleman,
Neville. 2001. 1001
Nudibranchs: Catalogue of Indo-Pacific Sea Slugs. Neville
Coleman's Underwater Geographic Pty Ltd, Australia.144pp.
- Coleman,
Neville, 1989. Nudibranchs
of the South Pacific Vol 1. 64 pp.
- Humann, Paul
and Ned Deloach. 2010. Reef
Creature Identification: Tropical Pacific New World Publications.
497pp.
- Gosliner,
Terrence M., David W. Behrens and Gary C. Williams. 1996. Coral
Reef Animals of the Indo-Pacific: Animal life from Africa to Hawaii
exclusive of the vertebrates Sea Challengers. 314pp.
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