Dear Jim & Harry,

According to Snyder (2003, Catalogue of the marine gastropod family Fasciolariidae, Academy of Natural Sciences of Philadelphia, special publication 21, p. 156) the horse conch should be known as Triplofusus papillosa G. B. Sowerby, I, 1825.  Sowerby's name is a senior synonym of gigantea Kiener, 1840 according to Snyder.

I know little about Fasciolariidae but this is an interesting outcome given the wide use of the name gigantea.

Yours,


John K. Tucker
-----Original message-----
From: "Harry G. Lee" [log in to unmask]
Date: Fri, 14 Dec 2007 07:26:06 -0600
To: [log in to unmask]
Subject: Re: [CONCH-L] What are we calling the Horse Conch?

Dear Jim,

Your question involves both nomenclature and taxonomy.

 From a nomenclatorial perspective, the generic unit Triplofusus was
proposed by Olsson and Harbison in 1955 as a subgenus of Fasciolaria
Lamarck, 1799.  Fasciolaria gigantea Kiener, 1840 (Horse Conch) was
selected as the type species.  Lamarck based his genus on Murex
tulipa Linnaeus, 1758, now called Fasciolaria tulipa (Linnaeus,
1758), the True Tulip.  So it is clear (by definition) that the Horse
Conch belongs in Triplofusus, and when that generic unit is raised in
rank to full genus, the name becomes Triplofusus giganteus (Kiener,
1840) - the author's name and date of description enter parentheses,
and the species level name, an adjective, is declined to conform to
the masculine gender of the "new" genus.

The taxonomic issue is whether Triplofusus warrants full generic rank
in the context of other possible generic assignments for the Horse
Conch (e.g. Fasciolaria, Pleuroploca, etc.).  Beginning before, and
in near consensus after, Olsson and Harbison (1955), most authorities
separated the Horse Conch from the True Tulip at the full generic
level since there are lots of differences in the shells (among other
attributes).  The tendency in the second half of the last century was
to place the Horse Conch in the genus Pleuroploca P. Fischer, 1884,
which is based on Murex trapezium Linnaeus, 1758.  More recently,
workers such as Bill Lyons have indicated there is sufficient
difference between Murex trapezium Linnaeus, 1758 (an Indo-West
Pacific species) and the Horse Conch to warrant separate genera for
the two, and, for what it is worth, I agree.

Ergo:
Fasciolaria tulipa (Linnaeus, 1758)
Pleuroploca trapezium (Linnaeus, 1758)
Triplofusus giganteus (Kiener, 1840)

Three species, each sufficiently different to warrant placement in a
different genus.

There is no publication that "officially" makes the transition from
Pleuroploca gigantea (Kiener, 1840) to Triplofusus giganteus (Kiener,
1840); that is not exactly the process in which taxonomy
operates.  At some point Bill Lyons may painstakingly explain why the
two genera are separate entities; for now it's fine to make up your
own mind using the principles I have roughly outlined for you above.

Harry


At 07:04 AM 12/14/2007, you wrote:
>Greetings from Tallahassee, where we hit record highs three days in a
>row ("Global warming? Impossible!" We'll study it for 20 years until
>the Democrats and Republicans alike are wearing SCUBA gear to work!)....
>
>What are we calling the Horse Conch these days? Seems I read that
>Pleuroploca gigantea has been given a different name. Since we talked
>about them a little, what's the correct Latin designation?
>
>Thanks in advance (now I have to go turn on the A/C) ....
>Jim

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