Re: Cephalopod parasites (from S. Carlson)

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Date: Fri, 11 Aug 1995 09:19:47 -0800
To: paleonet-owner@nhm.ac.uk
From: carlson@jade.ucdavis.edu (Sandy Carlson)
Subject: Re: Cephalopod parasites
Status: O

This occurs in living brachiopods, as well.  Spionid polychates settle
between the mantle and shell and the brachiopod secretes a blister around
the irritation.  It is very commonly seen in _Terebratalia transversa_ in
Puget Sound, Washington.
                                        Sandy

>North American oyster fisheries are adversely affected by (amongst others)
>`mud worms' (_Polydora_websteri_) which form so-called mud blisters by two
>separate processes: by boring through the shell; and by inserting
>themselves between the mantle and the shell.  The oyster's response is the
>same in both cases: it secretes a thin shelly deposit over the worm.  This
>is bad for the commercial fishery, but makes an excellent refuge for the
>worm.  Perhaps something similar to the second scenario was happening with
>Neale's ammonites?
>
>Ref: Haigler, S. A. 1969.  Boring Mechanism of _Polydora_websteri_
>inhabiting _Crassostrea_virginica_.  American Zoologist, 9(3 ed.2): 821-828
>
>
>>David Campbell writes:
>>        The inclusions in Pliocene Mercenaria (also found in various other
>>venerids, Recent and fossil) are calcite patches without any macroscopic
>>surface relief.
>>        Blister pearls are a fairly common response to parasites or other
>>foreign debris.  A Crassostrea virginica I obtained from the local seafood
>>market for DNA analysis has a blister pearl with no obvious external
>>association, although there are numerous clionid-like holes in the outer
>>layer.