Strombs develop the flared lip at maturity, then never grow larger.
However, as the animal moves around, the shiny, smooth lip abrades on
the sand and becomes uncomfortable for the animal whose body is often
in contact with it, so the mantle secretes more shell material over the
lip. As time goes by, the lip gets thicker and thicker, and since the
nacre is not really clear, as the layers add up it begins to  look
darker until  the oldest shells have very thick, gray lips (called
"samba" in some species).

If any algae manages to grow on the lip, the next layer will cover it
over, making green patches, usually around the edges. Of course, these
are poor specimens and should be left to breed.

This additional shell material makes less and less room for the animal
in the  shell, so it "loses weight" and becomes smaller as it ages.
Therefore, the largest meat-to-shell ratio occurs just before the lip
forms, while the animal is still  immature (not yet breeding age), and
many conch fishermen prefer to collect their conchs at this stage, thus
depleting the breeding stock. That's why it's against the law to
collect conch that haven't turned the lip in the Bahamas and several
other Caribbean countries (not that that stops some of the fishermen!)

Peggy



One is relatively thin, with refined sculpturing, as in the Bahamas.
>
> The other is heavy, coarse, very thick-lipped, with dark gray on the
> outer
> lip and parietal area as in St. Martin, not very far from the Bahamas.
>
> The habitats are similar, seems to me.
>
> Have other sculptural variations been found? Are they named?
>
> David Kirsh
> Durham, NC
>
>
           Peggy Williams: shell collecting trips
          Visit my website: www.Shelltrips.com
                               PO Box 575
                        Tallevast FL 34270
                           (941) 355-2291
                   [log in to unmask]