Unusual seashell or something other ?

[simsim]

What is this ?

<a href="http://www.radikal.ru" target="_blank"><img src="http://s50.radikal.ru/i128/0909/da/c90259574b2d.jpg" alt="http://s50.radikal.ru/i128/0909/da/c90259574b2d.jpg" style="border:0" /></a>

[paul monfils]

Under the name "worm shells" fall two quite different groups of animals.  Some such tubes or "shells" are made by actual worms - marine relatives of earthworms.  Others are made by specialized families of mollusks.  This appears to be a molluscan "worm shell", made by an animal in the genus Serpulorbis, in the family Vermetidae.  They grow attached to hard surfaces - rocks, coral, and other shells. I may be able to determine the exact species if you can identify the geographic locality where it was collected.  <span class="petit">--Last edited by Paul Monfils on 2009-10-09 03:02:47 --</span>

[simsim]

The shell was collected in Mediterranean

[ale.v]

It is a Serpulorbis arenaria (L., 1767)

[ale.v]

The shapes of the Vermetidae are really "free", so tje classificazion isn't easy.

By the way the most common Mediterrean Vermetidae are Vermetus triquetus and Serpulorbis arenaria.

Vermetus triquetus has a typical "line" all along the shell, while Serpulorbis has more coarsness.

I hope you can understand my poor english.

More than words, see at this link:
<a href="http://www.naturamediterraneo.com/forum/topic.asp?TOPIC_ID=4266" target="_blank"><!-- m --><a class="postlink" href="http://www.naturamediterraneo.com/forum/topic.asp?TOPIC_ID=4266">http://www.naturamediterraneo.com/forum ... IC_ID=4266</a><!-- m --></a>

[simsim]

Serpulorbis arenaria is presented on a sites :
<a href="http://www.gol.grosseto.it/acquario/vermetidae.htm" target="_blank"><!-- m --><a class="postlink" href="http://www.gol.grosseto.it/acquario/vermetidae.htm">http://www.gol.grosseto.it/acquario/vermetidae.htm</a><!-- m --></a>
<a href="http://www.gol.grosseto.it/acquario/serpulorbis_arenaria.htm" target="_blank"><!-- m --><a class="postlink" href="http://www.gol.grosseto.it/acquario/serpulorbis_arenaria.htm">http://www.gol.grosseto.it/acquario/ser ... enaria.htm</a><!-- m --></a>

and not alike on my shell

[dave r]

It certainly looks like S. arenaria to me, it is a very worn specimen you have so it may not look like some of the images on the net. I have to agree with ale.v on this one.
Dave

[simsim]

<blockquote><p><b>Quote :</b><table width="80%" border="1" style="border-color:#000099;background-color:#CCD4EC" cellspacing="0" cellpadding="0"><tr><td class="petit">ale.v wrote : The shapes of the Vermetidae are really "free", so tje classificazion isn't easy.

By the way the most common Mediterrean Vermetidae are Vermetus triquetus and Serpulorbis arenaria.

Vermetus triquetus has a typical "line" all along the shell, while Serpulorbis has more coarsness.

I hope you can understand my poor english.

More than words, see at this link:
<a href="http://www.naturamediterraneo.com/forum/topic.asp?TOPIC_ID=4266" target="_blank"><!-- m --><a class="postlink" href="http://www.naturamediterraneo.com/forum/topic.asp?TOPIC_ID=4266">http://www.naturamediterraneo.com/forum ... IC_ID=4266</a><!-- m --></a> </td></tr></table></p></blockquote>

Hi ale.v,  thank you for a help.
If to suppose that it Serpulorbis arenaria, that what is on these sites :

<a href="http://digilander.libero.it/conchiglieveneziane/gasteropodi/specie/SerpulorbisArenaria.htm" target="_blank"><!-- m --><a class="postlink" href="http://digilander.libero.it/conchiglieveneziane/gasteropodi/specie/SerpulorbisArenaria.htm">http://digilander.libero.it/conchigliev ... enaria.htm</a><!-- m --></a>
<a href="http://www.leganavalesulcis.it/view.php?pag=foto_portopino_sub&p=5&id=5" target="_blank"><!-- m --><a class="postlink" href="http://www.leganavalesulcis.it/view.php?pag=foto_portopino_sub&p=5&id=5">http://www.leganavalesulcis.it/view.php ... b&p=5&id=5</a><!-- m --></a>
<a href="http://www.naturamediterraneo.com/forum/topic.asp?TOPIC_ID=69306" target="_blank"><!-- m --><a class="postlink" href="http://www.naturamediterraneo.com/forum/topic.asp?TOPIC_ID=69306">http://www.naturamediterraneo.com/forum ... C_ID=69306</a><!-- m --></a>
<a href="http://www.argonauti.org/forum/topic.asp?TOPIC_ID=6407&whichpage=4" target="_blank"><!-- m --><a class="postlink" href="http://www.argonauti.org/forum/topic.asp?TOPIC_ID=6407&whichpage=4">http://www.argonauti.org/forum/topic.as ... hichpage=4</a><!-- m --></a>
<a href="http://waste.ideal.es/especies103.htm" target="_blank"><!-- m --><a class="postlink" href="http://waste.ideal.es/especies103.htm">http://waste.ideal.es/especies103.htm</a><!-- m --></a>
<a href="http://www.nmr-pics.nl/Vermetidae/album/index.html" target="_blank"><!-- m --><a class="postlink" href="http://www.nmr-pics.nl/Vermetidae/album/index.html">http://www.nmr-pics.nl/Vermetidae/album/index.html</a><!-- m --></a>  

Possibly, the error in the classification of the shell is committed on yours site ?  <span class="petit">--Last edited by SimSim on 2009-09-24 07:40:40 --</span>

[ale.v]

I'm not understanding which is your problem.

Are you still in doubt with the classification?
Why?


Rember that the shape is not important, because it depends on the environment.

For the classification I follow this two steps:
1) The specimen is from Mediterrean see
2) The specimen has several "nubby" (hope the word is correct) lines, clearly visible in your pictures, in particular in the upper-right one.

[simsim]

<blockquote><p><b>Quote :</b><table width="80%" border="1" style="border-color:#000099;background-color:#CCD4EC" cellspacing="0" cellpadding="0"><tr><td class="petit">Dave r wrote : It certainly looks like S. arenaria to me, it is a very worn specimen you have so it may not look like some of the images on the net. I have to agree with ale.v on this one.
Dave </td></tr></table></p></blockquote>

You assert that the shells of one family they can have absolutely different form, construction and vector of the direction of the coils of the spiral ?