I have often wondered about this. We have a food shell here (Lambis
lambis) that we call ganga, and it is often sold door-to-door by reef
scavengers' wives. It can, like squid rings, be quite tasty if you
cook it
properly, with a bit of patience. Instead, it usually tastes like a
rubber
eraser dipped in oyster sauce.

We also have its relative, Lambis chiragra, called lima-lima, meaning
5-5,
because it has 5 arms on its front lip (and one on the back).

Back to the point, though. Lambis lambis seems to grow remarkably fast,
considering that almost every adult is picked up by some human reef-
scavenger, and eventually eaten. When I'm reef-scavenging myself, I
rarely
come across juveniles (or perhaps, since I ignore them, I'm under-rating
their numbers). Considering the decimation of adults caused by reef-
harvesting, they are still very, very common.

American conches seem to do about the same. There have been huge
harvests
of them in the Caribbean, but they're still there, so they must have
evolved a very quick reproduction-and-maturing system.

About whelks, I'm not so sure, but we have the 'fox whelk', Fasciolaria
trapezium, which is not so common, but has a very strong, large shell
(with knobs on).

Last night, I heard a helluva din outside my bedroom door. The perp
turned
out to be a hermit crab inside a very large Fasciolaria trapezium shell.
It was climbing up my bookshelves and falling off, which made the
noises.

I'm used to the usual hermit crabs; they wander in, you pick them up,
they
curl up their claws (in an absolutely perfect fit to the shell aperture)
and you throw them out again.

But this one didn't. When I picked him up, to throw out, he wasn't at
all
shy; he tried to attack my fingers.

He was, I'm reasonably sure, a young Birgus latro, the coconut crab that
grows to a huge size, but lives like a hermit crab in a shell when it is
an infant - see:
http://en.wikipedia.org/wiki/Coconut_crab
http://www.coconutstudio.com/Shoreline%20Foraging.htm

The coconut crab can climb up a coconut tree, get a tasty young coconut,
and then crack through its shell. See:
http://www.coconutstudio.com/Coconut%20Origins.htm

So I was very glad to see that a young Birgus latro was invading my
home,
and making such a noise, and got all goo-goo, because they are getting
very rare here now.

So I put it, gently, back on the floor.

When it woke me up again, at 3am, climbing up my bookshelf, and falling
off, I picked it up and threw it out of the window.

That doesn't tell you a lot about whelk growth, but it may do about
other
animals that choose fast-growing, strong shells for their homes.

regards

Richard Parker
Siargao Island, The Philippines.

My website at www.coconutstudio.com is about the island and its people,
coastal early humans, fishing, coconuts, bananas and whatever took my
fancy at the time.





On Sat, 28 Apr 2007 12:45:45 -0400, James Parrish
<[log in to unmask]> wrote:

> I have several 7'' - 8'' knobbed whelks and I was just curious how
> long
> did it take for the whelk to grow to that size?  Are we talking
> months?
> years? decades?
> What is the life span for a mollusk?  I realize that it will vary
> between
> species, but what is the average?
> Thanks,
> James
>
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