a marine Phoronis larva

[Franz Neidl]

Two days ago I found this Actinotroch larva from a Horseshoe worm (Phoronidae). I think this is Actinotrocha branchiata but I am not completely sure about it.
This larva has a very interesting shape and an interesting metamorphosis to an adult animal.
2 pictures with Obj. 10x, DIC.

Franz

[Charles Krebs]

Franz,

Once again you have shown us a bizarre and wonderful creature that is probably new to just about everyone here. (Well I can think of a few likely exceptions... we've got some pretty sharp folks hanging around here)

And photographed beautifully!

[BJ]

Dear Franz,

thank you for another fascinating subject, beautifully photographed.

I am sure (well 99.9%) that you are right with your identification. The number of tentacles is important (although the number increases as the larva grows). I count at least 14, most other species have ~10 or less. Another key point is the presence of pigmented spots on the "hood" and base of the tentacles. Finally size is a clue, the larvae of most species are <1000 um. Actinotrocha branchiata can get up to 2000 um.

We must drag Charles away from his nail polish (!) and get him to give you some competition with the marine plankton.

thank you,
kind regards,
Brian

[Charles Krebs]

Brian.... when I said this was likely new to us here...with a few exceptions... you were at the top of my exception list!

[Wim van Egmond]

Dear Franz,

It is great to see all your plankton finds. It is such an endless source of wonders. This is a very spectacular one and excellent images. Perhaps interesting to look at 2 images that I have posted a long time ago.

http://www.photomacrography.net/forum/v ... ight=larva

Wim