At 01:20 PM 1/6/98 -0400, you wrote:
>>Speaking of bryozoans (I think): I collected some weird dead things at
>>minus tide at Fort Amador, Pacific Panama. Ranging from 5mm to 12mm they
>>were vaguely reminiscent of Attiliosa nodulifera with small evenly spaced
>>bumps, an oval aperture with sharp angles top & bottom, gastropod-like.
>>They turned out to have various dead gastropods inside, but those were
>>covered with a 2-3mm thickness of porous bryozoan-like material, including
>>the bumps.
>If the apertures were shaped like a capital "D", they probably were a
>hermit crab-bryozoan symbiosis.  The bryozoan growing on the shell can
>thoroughly obscure the shape of the original shell.  The hermit crab
>doesn't have to keep finding new shells-the bryozoan grows along with it.
>The "D" shape matches the shape of the crab.  Such symbioses are well-know
>from the fossil record (with bryozoans, coral, or hydrozoans coating the
>snail), but rarely documented from the Recent.
>
>David Campbell
>
The apertures are more oval than "D" shaped, but I think you have the right
explanation. Thanks.
 
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