David
That is a good point about the cone shape radiating away.  I think the effect of
the water in the cone is still part of it though, as it is a buffer helping to
lessen the impact of rapid temperature change in either direction.  I may have
made this up in my head, but I really think I read it somewhere, I don't think I
can take credit!

Nora
Calgary, Alberta
(keep forgetting to add this!)

David Kirsh wrote:

> Tall is cool.
> High cones might be explained by the need to avoid overheating but that is
> probably not related to space for water (since water, once heated, will
> retain heat longer).
> The greater surface area of the high cones will radiate heat away from the
> limpet more quickly than the squat, compact limpets. There are many
> examples of this principle in the plant and animal kingdoms, in which there
> are intuitively unexpected structures in heat-exposed organisms. The
> stegosaurus' plates may have served this thermoregulatory purpose.
> -David
> >Hi all limpet lovers,
> >This is a very technical question (why and how limpets are more conical at
> >the higher-energy swash zone than lower on the beach).  I couldn't even begin
> >to say how but I have heard that it is advantageous to limpets to be more
> >conical where they are more exposed to protect them from temperature
> >extremes.  The idea is that the water in the apex of the shell provides a
> >measure of protection against overheating, and against cooling to a lesser
> >degree.
> >I just got back from a week on the west coast (a near first for me) and saw
> >many, many limpets.  I collected some and and still having fun identifying
> >them.  I can attest to the stats discovered by our student as the limpets
> >(still haven't figured out which type) I saw in one bay on rocks right at
> >high tide were very highly conical, as high as a Whitecap Limpet (Acmaea
> >mitra).
> >A good work on natural history of mollusks is "Living Marine Molluscs", by
> >C.M. Yonge and T.E. Thompson, published in 1976 by Collins, London. This book
> >has good info on limpets and may also have some more detailed listings in the
> >bibliography.
> >
> >
> >Lynn Scheu wrote:
> >
> >> I have a request for information here below. Can anyone help Anthony?
> >> Please send your answers to Conch-L or to me personally at
> >> [log in to unmask]
> >>
> >> Thanks for any help,
> >>
> >> Lynn Scheu
> >> Louisville, KY
> >> [log in to unmask]
> >>
> >> > Hi there!
> >> >          I'm a third year undergraduate here in the UK, my name's
> >> > Anthony Jones, i'm an environmental science student.  Recently my class
> >> > took a field trip to a rockyshore habitat, there we examined the shapes
> >> > of limpets within the intertidal zone, since then several statistical
> >> > methods have been employed to determine if the shape of the shell
> >> > varies within the intertidal zone, the results, as previously thougth,
> >> > confirm that indeed they do.  Limpets being more conical at the high
> >> > energy swash zone, and more flatter, with a rounder apex and the sub
> >> > inter tidal zone, this was the reverse of what the students expected,
> >> > our lecturer however said this was correct, he then set an assignment
> >> > for us to found out why and how this change is induced, we know it's
> >> > not genetic, that the change is environmentally induced, but more
> >> > information is needed, i suspect it have something to do with the
> >> > attachment mechanism employed by the limpet to attach itself to the
> >> > substrate, but have failed to come up with any information pertaining
> >> > to the explanation.  Okay any information or pointers to where i'd be
> >> > able to find out about this would be much appreciated.
> >> >
> >> > Yours
> >> >
> >> > Anthony Jones