Unknown animal living in a featherstar

The Animals were living in a featherstar.

They were moving over the body of the featherstar and tried to hide. But they always stayed at the body and never went out to the “arms†of the featherstar.

I took the picture last year (21. April 2006) at the Philppines at a divesite called: Housereef of Swiss Bamboo House at Alona Beach (Panglao Island).

Philippe (from www.poppe-images.com ) told me, that’s maybe some kind of comb jelly…., but he also wasn’t sure.

No, they're not ctenophores at all. They belong to a group of bizarre worms called Myzostomida that were traditionally placed with polychaetes. Recent work based on DNA has been contradictory. One line of study says they're not annelids at all while the other line says they are.

All myzostomes are endo- or ecto-parasites on echinoderms in general & on crinoids in particular. Each species seems to have a particular niche on usually one or a few species of echinoderms. Some are only on the cental disk, others on the arms, some live inside the digestive area, and other live inside cavities or galls made by the echinoderm in response to the parasite's presence. The external ones match the coloration of the host. In this case they're white with black spots just like the crinoid. Your pictures are outstanding - you can even see bulges which indicate the paired parapodia ("leg") structures on the underside of the body.

Did you notice the copepod in the blow-up? Some of them are host-specific commensals as well, although the one in the image looks like a typical free-living species.

Great, now we know what the animal is! thx

Philippe

Hi Leslie,

thank you a lot for helping me to identify that worm and for the compliment for my pictures.

No, I didn’t see the copepod, but after a short search I found it.

Can I post your comment about the worm on my webpage, when I upload the picture there?

Regards and thank you again

Thomas

Sure, feel free to quote me.

Got any more cool invert pics?

cheers, Leslie

ooooooooo

that is a way cool find!

Hi Leslie,

Here I have you some more pictures.

Do you know the exact name of these worms?

The green one was very tiny (about 5…10mm) and I found it on a sea squirt (probably Didemnum molle).

cheers, Thomas

Thanks for posting! There's nothing I like better on a lazy saturday morning than looking at images.

#3 is my favorite -- it's the tube of a polychaete in the family Terebellidae, genus Lanice. Thse are known as windmill worms because of the sand rays at the tube opening. The worms stretch their long feeding tentacles over the rays to catch food particles floating in the water.

# 2 is a common flatworm Pseudoceros lindae. One of our members, PP, has a wonderful series of photos of these mating ("penis fencing") on his website <www.ppfotos.com>

# 1 is another flatworm. I've seen pictures of it before but I can't remember if there was a name attached to the images. Many flatworms feed on tunicates. Judging by the color this one may be a specific predator of Didemnum molle.

The first (green) Picture is absolutly fantastic!

Very interesting, I have always wondered what these little animals were, I always thought they were some kind of flatworm related animal!

Thanks again Leslie for your Information.

Here I have some more worm pictures, just for take a look at them….

Probably they are: #1: Gastrolepidia clavigera #2: Paraplanocera sp #3: Asterophilia carlae

If not, please tell me the correct name.

Thomas

1 and 3 are fine (very nice shot of the Asterophilia) but as for 2, well, I just don't know. I"m not even sure it's a flatworm. If it is, it's very damaged.

Thomas - did you photo the crinoid that the myzostomes were on? If you don't mind I'd like to send the pics to a colleague who works on the group. I'm sure he'd like to know the crinoid species as well.

Leslie – Yes I did :-) Just send him the pics. Would be nice, if you can post his answer too in the forum or you can mail it to me.

About the second picture in my last post: I found on poppeimages a quite similar picture, so I thought that it’s probably the same.

For details see:

http://www.poppe-images.com/images/image_i...hp?picid=933217

They may be the same, I just don't know enough about flatworms to be sure. Identification is based on internal characters so flatties without distinctive color patterns are very hard for non-specialists to id. I'd rather admit I don't know at the start than try to guess.

Hi Leslie and All?

Something similar?

http://www.poppe-images.com/images/image_i...hp?picid=942877

greetings

Philippe

Philippe, I don't really know about this one. Some myzostomes are long & narrow but that thin outer margin reminds me of a flatworm. If you see one again gently turn it over & take a photograph of the ventrum. A myzostome will have several pairs of short appendages tipped with large hooks. Better yet, put it in a vial and send it to me!