Platydoris formosa from the Philippines

May 22, 2001
From: Mary Jane Adams

Hi Bill,
I found these two Platydoris formosa in a very strange place -- at the bottom of a barrel sponge! They were thrashing around as if trying to find a way out. When I picked them up they were tightly curled and felt hard and stiff. I put them on the sand to photograph them and was amazed to see them flatten and stretch out to about 18 cm in length.
Depth: about 10 meters, Divesite: Twin Rock, Batangas, Philippines, May 8, 2001.
Best regards,
Mary Jane

Adams, M.J. , 2001 (May 22) Platydoris formosa from the Philippines. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Thanks Mary Jane,
These 'red-splashed' or 'blood-spattered' platydorids are an amazing sight. Withour the red they would be almost invisible, so why the brilliant display. Perhaps their potential predators can't see the red? We have only just begun to realise just how complex the topic of colour and colour display is in these animals. One thing we can be sure of - the obvious answer is the least likely to be correct.
Bill Rudman

Rudman, W.B., 2001 (May 22). Comment on Platydoris formosa from the Philippines by Mary Jane Adams . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Platydoris formosa

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