my experience  is that historically "oysters" is often used as a common term
for a number of species...
for example, reports in the early 1900's of  "rock oysters", near Victoria,
B.C. were the rock scallop,Crassadoma gigantea.

Atlantic oysters, Crassostrea virginica, in Boundary Bay, B.C. are found
several km (at least three km... probably more) up the Serpentine River.

Rick Harbo
Nanaimo, B.C.

----- Original Message -----
From: "Paul Monfils" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, November 13, 2001 7:13 PM
Subject: Re: Oysters


> I don't think any true oysters (family Ostreidae) live in completely
> fresh water.  But they can get pretty far up into river estuaries where
> the water is quite brackish.  In some cases, this could be a half mile
> or more inland.  So theoretically, I think they could have come from
> near or within the mouth of the Thames, but not likely from its
headwaters.
>
> Paul M.
>