I've observed that c. carneola and nebrites immediately pull in their mantle
and foot as soon as you turn over their rock.  They immediately fall off the
rock into the sand and will not expose their mantle while you wait and watch
(this assumes they are not sitting on eggs, in which case they hang on for
dear life).  C. grayana, lynx, caurica and pantherina will retract their
mantle but hang on with their foot until pushed off with a finger.

C. gracilis will keep their bright red/orange mantle out even if exposed,
but on touching will retract it but still hang on with their foot.

C. turdus seem the most relaxed about the whole thing.  I've picked up c.
turdus and played with them and they still won't retract their mantle.  They
have no concerns about walking across your hand with their mantle fully out.
For some, you have to "push" their mantle down off the mantle to get them to
expose their dorsum.

So it all depends on the species.

Don Lycette
Al Jubail
Saudi Arabia


> -----Original Message-----
> From: [log in to unmask] [SMTP:[log in to unmask]]
> Sent: Thursday, May 25, 2000 10:36 PM
> To:   [log in to unmask]
> Subject:      Re: bones, teeth, humans and molluscs
>
> Interesting to observe that the mantle is separate from the soft parts of
> the
> animal. It can be retracted or extended without the animal moving at all.
> You
> see this most often on brooding females that are disturbed by just
> touching
> the shell with a small stick. The mantle will retract but the rest of the
> animal does not move.
>
> In my observations the animal does not retract into the shell, even when
> threatened, unless it is knocked off it's perch. The mantle was retracted,
> but the animal did not retract unless moved or touched.
>
> Most of these were shells in the inter tidal zone, so I can't speak for
> shells in deeper water. If I remember correctly the several Cyp cernica
> that
> I found in shallow water seemed braver than the other shells I observed.
>
> Frank in Massachusetts (where it doesn't seem know what it wants to do
> weather wise. But the Sox are in 1st place)