Hi All,

As James says, this is probably a species of Stomatella.
(I have heard of "hole-less" abalones, though.)  I collected
several in Tonga a couple of weeks ago, and all but one
autotomized a large part of the foot as I collected it.  Un-
like the harps, which only autotomize a relatively small
portion of the foot, the Stomatella I collected dropped a
piece almost as large as the remaining animal.  In the
second volume of Cernohorsky's "Marine Shells of the
Pacific" he states that "Autonomy[sic] has been observed
in this species," referring to Stomatella auricula (Lamarck,
1816).  He continues to say that S. nigra Quoy & Gaimard,
1834, from Tonga is a dark variant of S. auricula.

While we're chasing Stomatella species, as I have been
for a few weeks, here's another note or two about the
genus.  Barry Wilson continues the Stomatella lumping
by stating, in "Australian Marine Shells, Vol. I," that
Stomatella auricula should be synonymized with S.
impertusa (Burrow, 1815), though it looks like he changed
his mind about which name to use while the book was
being written.  He agrees with Cernohorsky that S. nigra
is a form of S. auricula (=S. impertusa).  He also says
that Stomatella (Gena) varia (A. Adams, 1850) should
probably be synonymized with S. impertusa.  After read-
ing all of this, I found myself rapidly running out of names
for the three "species" of Stomatella that I collected in
Tonga.

Three of the shells I found look almost exactly like the
ones figured in Wilson's book, identified as S. impertusa.
(They don't look much like the photos of S. impertusa in
the Compendium--note the outline of the outer lip.)  They
are glossy, red-brown-white mottled, with a somewhat con-
cave outline to the lip, and a low spire set very close to
the columellar edge of the shell.  A fourth shell appears
very different from these, being yellow with grey markings,
and has a straight lip and an elevated spire that is moved
inward toward the center of the shell.  The fifth and last
Stomatella is solid black, elongate, and has a straight lip,
but the low spire is very near the edge of the shell like the
first three I mentioned.

Looking at the shells carefully might have led me to be-
lieve that there were multiple species in this group, but I
have to admit that it was the animal characteristics that
made me look at them closely.  All of the animals were
cream colored, had a large percentage of the foot exposed
around the shell, and all of them attempted to "hunker down"
initially when I flipped their slabs over.  (They were about as
tough to remove as limpets or abalones when they were
clinging to the slabs.)  Within a few seconds of being ex-
posed to the light, they all left their spots and moved rapidly
toward holes or the sides of the slabs, and they all dropped
part of their feet when I picked them up.  All but one, that is.
The black Stomatella only had a small amount of its foot
exposed around the shell, and it was solid black also.  This
one did not behave like the others, and slowly crawled from
his spot as soon as I exposed him to sunlight.  He wasn't
stuck to the rock like the others, and didn't autotomize
any of his foot.  (Maybe he had already done this recently?)
The entire animal was flat black, and no other colors could
be seen, even when I removed the animal from the shell.
If I had realized that there was any possibility that all five
of these could be the same species I would have certainly
paid more attention to the animals.

If all the species I mentioned in this e-mail truly should be
in synonymy with S. impertusa, it really is a variable species.
Variable color, gloss, lip outline, length/width ratio, spire
height, spire placement, animal coloration, and maybe even
animal behavior.

So, I guess Benjamin's molluscs are Stomatella impertusa...

Cheers,



Don



----------
From: Charles Sturm <[log in to unmask]>
To: [log in to unmask]
Subject: mollusca abalone without holes? (fwd)
Date: Thursday, February 17, 2000 5:35 AM

Anyone have a suggestion for this fellow?  Please respond to him directly
as this request was forwarded from a different discussion group.
  Thanks.

Charlie
******************************************************************************
Charlie Sturm, Jr
Research Associate - Section of Invertebrate Zoology
                     Carnegie Museum of Natural History, Pittsburgh, PA
Assistant Professor - Family Medicine

[log in to unmask]


---------- Forwarded message ----------
Date: Thu, 17 Feb 2000 13:14:11 +1000
From: Benjamin Vallejo <[log in to unmask]>
To: Multiple recipients of list <[log in to unmask]>
Subject: mollusca abalone without holes?
Resent-Date: Wed, 16 Feb 2000 22:41:53 -0500 (EST)
Resent-From: [log in to unmask]
Resent-To: [log in to unmask]


Dear mollusc people:

I have been sent two shells of an abalone-like gastropod from the Sulu
Archipelago, Philippines. Its black 2 cm maximum shell length, apparently
collected on basalt rocky shores at a single beach in Tawi Tawi province,
Philippines. The field record says it was collected at low tide and the
animal lives on volcanic cobbles. The foot drops off if the animal is
startled. It does look like an abalone except it has none of the diagnostic
holes on the valve and the interior is nacreous. If it is a limpet, it has a
definitely odd shape.

I have seen juvenile abalones less than 2 cm in length and they always have
the diagnostic holes. Can anyone give their ideas on what this shell is
this?


Sincerely
Benjamin Vallejo
School of Marine Biology and Aquaculture
James Cook University
Townsville 4811 Qld.
Australia

Voice : 61 7 4781 4203
Fax : 61 7 4725 1570

"It is advisable to look from the tide pool to the stars and then back to
the tide pool again."

John Steinbeck