February 22, 2010
From: Sharyn Reen
I would really like to find out the ID of this fellow I found whilst walking our local beach. I have tried to find out about it online and have found many spectacular looking creatures but none quite like this one.
Locality: Armstrong Beach, On shore, Queensland, Australia, Coral Sea, 10 February 2010, Found a couple of these washed ashore after rough weather.. Length: Approx 10 cm. Photographer: Sharyn Reen.
Thank you for your help.
firstname.lastname@example.orgReen S.L, 2010 (Feb 22) Armstrong Beach, Queensland. What is it?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/23252
This is not a sea slug, but since some sea slugs eat your mystery find, I'll break my rules and give you a short answer. It is a Sea pen [Order Pennatulacea] which are animals related to sea anemones, corals and jellyfish. Each 'animal' is a colony of smaller animals. The fleshy bare cylinder is an anchoring rod, which is normally embedded into the mud or sand. The feathery part consists of layers of flaps, which can expand out into the water, and at the edge of the flaps are a row of small animals called 'polyps', which look like small sea anemones. Sea Pens live offshore in sheltered bays. I suspect your animal has been 'uprooted' by heavy seas and washed ashore.
One genus of sea slugs [Armina] feed on sea pens. Have a look at the messages on the Armina califomica page for more photos of sea pens in a slightly more healthy condition than yours. If any one has a nice photo of a healthy sea pen it would be good to add it to the Sea Pen page.