March 15, 2010
From: Leanne and David Atkinson
Concerning message #23276:
You asked for photos of Sea Pens. We get several types of Sea Pen here so I will send some more messages showing the different varieties [see messages #23326, #23328]. They are something we see in the Port Stephens-Great Lakes Marine Park regularly over all of the dive sites. Here are our second series of photos. The first photo shows a Sea Pen stalk with Polyps out. It was taken at Fly Point, Port Stephens-Great Lakes Marine Park, Port Stephens, NSW Australia in 8metres of water. The next two show Sea Pens from The Pipeline with a close up of the Polyps. Both of these were taken at The Pipeline, Nelson Bay Port Stephens.
Locality: The Pipeline, Nelson Bay, Port Stephens, 8metres, New South Wales, Australia, Pacific Ocean, 07 March 2009, Sandy bottom with scattered Sea Pens, sponges, bryozoans, gorgonias, soft corals, hydroids and ascidians. Length: 30mm. Photographer: Leanne and David Atkinson.
Hope these are of interest.
Leanne & David Atkinson
firstname.lastname@example.orgAtkinson, L. & D., 2010 (Mar 15) Re: Sea pens . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/23327
Dear Leanne and David,
This is one of a small group of sea pens which have a sausage-shaped body with the polyps radiating out in all directions. They differ from the more speciose 'feather-shaped' species which gave the group the name 'sea pen' because of their resemblance to quill pens.
In my comment to your earlier message [#23326] I wondered just how specialised species of Armina would prove to be in their food choices when sufficient observations were made. Interestingly this sea pen seems to be the one that Armina sp. 9 is feeding on in an earlier message of yours [#13514]. Perhaps it would be a nice study to do on the Port Stephens area. Although we cant name either the sea pens or the Armina species at present, they are sufficiently distinct from eacch other to identify and give them temporary names.