>Thanks, Andrew. I know sponges are found in kitchens but I never thought of
>them as food items. Would make one feel bloated, no?

If you swallowed one whole, for sure! Calliostoma's radula is a nasty
rasp designed to tear sponges to shreds. I'm not sure whether their
dioet extends to siliceous and calcareous sponges, or is restricted
to cormeous ones.

>Do we know whether Calliostoma might be eating something associated with
>sponges?

Not as far as I know, but I'm FAR from being an expert!

>And I've never come across the term dewatering. Does that mean these are
>vents spewing gases that displace water?

As new sediments are laid down they trap interstitial water between
the grains. As more sediment is laid down the trapped water must
escape as the rock is compressed under the pressure of the sediments
above. It may espcape between the grains without dirupting the
overlying layers. It may burst through in places, producing
disruptions called flame structures in some of the overlying layers.
Or it may find preferred pathways and slowly flow upward toward the
surface; if there are dissolved carbonates etc in the water this may
be deposited in places in the surrounding sediments, producing
tubular concretions with a very small (generally millimeters in
diameter) central passage. These chimneys are about 5-20cm in total
diameter and may contain embedded shells; they may or may not extend
to the surface and may branch. There are lots off the Dunedin shelf
edge. Most are broken off and lie in patches on the seafloor.

>Never heard of the 5-message limit before, either. Maybe this is something
>new to head off some of the troubles from months past.

I have only just rejoined the list, having set "no mail" long ago
because of the large number of wierd postings produced by a very few
people, who appear to be no longer on the list. Lynn Scheu told me
they'd been warned or canned. But when the list is running smoothly,
with not a lot of postings in total, such a limit is too low or
unnecessary. Hint hint...
--
Andrew Grebneff
165 Evans St, Dunedin 9001, New Zealand
<[log in to unmask]>
Seashell, Macintosh, VW/Toyota van nut