nudibranchs text index | photo index
Phylum Mollusca > Class Gastropoda > sea slugs > Order Nudibranchia
Polka-dot nudibranch
Jorunna funebris
Family Discodorididae
updated Sep 12
Where seen? This distinctive elegantly-spotted nudibranch is regularly encountered on many our shores. Sometimes lots are seen. On coral rubble near reefs.

Features: 1- 6cm long. Fleshy oval body, white with black circular markings. These markings are actually made up of tiny raised black bristles on the skin (called caryophyllidia). In fact, the entire body is covered with bristles, which are mostly white, giving the animal a fuzzy appearance. It has black-tipped rhinophores and black edging on feathery gills on the back.

What does it eat? It is said to eat a blue sponge (Neopetrosia sp.). Indeed, on Pulau Sekudu, we have seen large Polka-dot jorunna nudibranchs near these sponges, sometimes in pairs, and sometimes appearing to have just having laid a ribbon-like egg mass. Elsewhere, we have also seen these nudibranchs near blue sponges.

Sentosa, Mar 05

A pair of Polka-dot jorunnas near
blue jorunna sponge

Black edged gills

The spots are actually arrangements
of tiny black bristles.

Polka-dot nudibranchs on Singapore shores

Photos of Polka-dot nudibranchs for free download from wildsingapore flickr

Distribution in Singapore on this wildsingapore flickr map


With egg mass near
blue jorunna sponge

Pulau Sekudu, Jul 05


Chomping on a blue sponge?
Pulau Semakau, Jan 09

Chomping on a blue sponge?
South Cyrene, Feb 11

Ate something large?
Pulau Semakau, Mar 08


Mating
Pulau Semakau, Feb 08

Mating
Tanah Merah, Aug 11

Tiny, about 1cm. Several seen.
Sentosa, Jan 06


Pulau Semakau East, Nov 14

Photo shared by Loh Kok Sheng on facebook.

Sentosa Tg Rimau, Oct 15

Photo shared by Loh Kok Sheng on facebook.
 


With egg mass
Pulau Sekudu, Jul 05

Underside


Tanah Merah, Aug 09
Photo shared by James Koh on his blog.

Sisters Island, Feb 08
Photo shared by Toh Chay Hoon on her flickr.

Terumbu Selegie, Jun 11

Photo shared by Neo Mei Lin on her blog.


Terumbu Pempang Tengah, May 11

Photo shared by Liana Tang on facebook.

Terumbu Pempang Darat, Jun 10
Photo shared by James Koh on his blog.

Terumbu Pempang Laut, Apr 11
Photo shared by Loh Kok Sheng on his blog.


Beting Bemban Besar, Apr 10
Photo shared by Loh Kok Sheng on his flickr.

Terumbu Raya, Mar 11
Photo shared by Russel Low on facebook.

Terumbu Bemban, Jun 10
Photo shared by Toh Chay Hoon on her blog .


Pulau Sudong, Dec 09
Photo shared by Loh Kok Sheng on his flickr.

Terumbu Berkas, Jan 10
Photo shared by Loh Kok Sheng on his flickr.

Pulau Biola, Dec 09
Photo shared by Loh Kok Sheng on his flickr.


Pulau Salu, Jun 10

Terumbu Salu, Jan 10
Photo shared by Loh Kok Sheng on his flickr.

Pulau Berkas, May 10
Photo shared by Loh Kok Sheng on his flickr.


Pulau Senang, Jun 10
Photo shared by Loh Kok Sheng on his flickr.
   

Polka dotted nudibranch from Loh Kok Sheng on Vimeo.


Polka-dot nudibranch at Sentosa from Loh Kok Sheng on Vimeo.


Links
References
  • 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.
  • 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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