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worms > Phylum Platyhelminthes > Class Turbellaria > Order Polycladida
Dawn flatworm
Pseudobiceros hancockanus*
Family Pseudocerotidae
updated Oct 2016

Where seen? This elegant flatworm is sometimes seen on coral rubble near living reefs on many of our Southern shores. Like the first light of dawn, the dark to black flatworm has orange and white edges. Previously known as Pseudobiceros uniarborensis.

Features: 5-8cm long. Usually with deep ruffles. Body dark brown to black. Margin in three colours: thin white line on the outermost edge, a transparent greyish band in the middle and orange band innermost next to black body. Centre of the body is raised, with a short grey or white stripe on the head. Underside uniformly semi-translucent grey with fine white margin. It has a pair of erect pseudotentacles at the front made up of folded edges of the body but lacks the marginal banding found in the rest of the body. The pseudotentacles are all black with white tips.

St. John's Island, Jan 06

Marginal band: orange, grey, white.
Pseudotentacles all black with white tips.
Grey or white stripe on the head.

Pulau Hantu, Sep 08

Tanah Merah, Aug 09

Underside uniformly grey semi-translucent.

Tentative identification. Species are difficult to positively identify without close examination.
On this website, they are grouped by external features for convenience of display.

Dawn flatworms on Singapore shores

Photos of Dawn flatworms for free download from wildsingapore flickr

Distribution in Singapore on this wildsingapore flickr map

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

Sentosa Serapong, May 15
Photo shared by Loh Kok Sheng on his blog.

Terumbu Raya, Aug 14
Photo shared by Jianlin Liu on facebook.

Terumbu Pempang Tengah, Sep 14
Photo shared by Loh Kok Sheng on his blog.

Pulau Tekukor, May 10
Photo shared by Neo Mei Lin on her blog.

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

Pulau Sudong, Dec 09

Pulau Salu, Jun 10

Pulau Senang, Aug 10

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

With grateful thanks to Leslie H. Harris of the Natural History Museum of Los Angeles County for comments on this worm and its identification.


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