Hi Steve,

Most of the small strombs are great jumpers, if not great
swimmers.  Terebellum terebellum is hard to collect for
just this reason, as they jet off like a rocket every time you
grab at them.  I've seen Strombus dentatus jump, then
continue to kick as they travel through the water, which
gives them the appearance of swimming.  I'm not sure if
this kicking actually makes them travel farther.

The flattened, white shell you saw swimming was most
likely a trochid.  Many of the trochids can swim by rapidly
twirling the foot around like a helicopter rotor.  They don't
seem to be able to do this for more than a few seconds at
a time, but can travel a considerable distance in those few
seconds.  Monilea callifera (Lamarck, 1822) and Monilea
belcheri (Philippi, 1849) are pretty good swimmers, as are
some of their relatives.  Most photos you see of these
species show the darker forms, but they may be almost
white in color.

In addition to these, some Oliva species may swim, or at
least "flutter" along the bottom just above the sand.  Many
species of Opisthobranchs also swim, as do most or all of
the pteropods.

I'm sure some of the others on the list will be able to pro-
vide some references for you, and add to the list of swimmers.

Cheers,


Don

----- Original Message -----
From: "Stephen Tettelbach" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, November 30, 2001 3:01 PM
Subject: swimming gastropods


> Greetings - I am trying to track down information on swimming behavior of
2
> marine gastropods. I have done a brief electronic literature search and
have
> spoken to a couple of colleagues, but have not been able to find much
> information to this point. If anyone out there can help I would be most
> grateful.
> During two different night dives in Fiji, 3 yrs ago, I observed gastropod
> swimming that greatly surprised me. The first was a pair of Strombus
> dentatus that swam about 1-1.5 feet off the substrate, with a hang time of
> about 1-1.5 seconds. I understand that Strombus terebellatus is a good
> swimmer, although I have not yet tracked down a reference on that.
> Does anyone know if this has been reported for dentatus?
>
> The second snail behavior was very bizarre. I observed a small (~1 cm
> diameter), flattened white snail that shot away from me and landed about
5-
> 6 feet away after i approached it. I caught up with it, then took one
macro
> picture of it, but before I was able to pick it up, it shot off again
(kind of
> reminiscent of the flight of a UFO actually) and landed even further away
> than the first flight. After extensive searching I was not able to find it
again.
> I never saw this behavior again. The one picture that I got is somewhat
> overexposed and I can not identify the snail. It looks somewhat like a
> Modulus.
>
> I will be returning to this site in January 2002 and will attempt to
follow up
> on these observations.
> If anyone has any thoughts/references, etc. that they might share I would
> greatly appreciate it.
>
> Sincerely, Steve Tettelbach
>
>
>
>
> Stephen T. Tettelbach, Ph.D.
> Natural Science Division
> Southampton College
> Southampton, NY 11968
> Email: <[log in to unmask]>
> Phone: 516-287-8418
> Fax: 516-287-8419
>