Date:         Mon, 13 Oct 2003 22:17:16 -0400
Reply-To:     Conchologists of America List <CONCH-L@LISTSERV.UGA.EDU>
Sender:       Conchologists of America List <CONCH-L@LISTSERV.UGA.EDU>
From:         "José H. Leal" <jleal@SHELLMUSEUM.ORG>
Subject:      Re: Poecilogony: pairs of species
In-Reply-To:  <5.2.1.1.0.20031013215636.00a077c0@pop.mindspring.com>
Content-Type: multipart/alternative;

For more on the Alvania faberi/auberiana pair check my old book (Leal, 
1991, Marine Prosobranch Gastropods from Oceanic Islands of Brazil), pages 
72-73, plate 7figs. A-I; poecilogony cannot be dismissed just because it 
hasn't been confirmed.

Hugs,

José

At 09:57 PM 10/13/2003 -0400, you wrote:
>Dear Marco,
>
>This is an excerpt from at report on Stosicia at 
><http://www.jaxshells.org/907d.htm>:
>     "If we look at other groups in which sympatric pairs of 
> closely-related marine snails having utterly different protoconchs much 
> as do our two species, a few instances in the Caribbean fauna leap to 
> mind in which the teleoconchs are actually even more similar: Alvania 
> auberiana (d'Orbigny, 1842) / A. faberi de Jong and Coomans, 1988, 
> Retilaskeya emersonii (C. B. Adams, 1845) / R. bicolor (C. B. Adams, 
> 1839), and Iniforis turristhomae (Holten, 1802) / I. casta (Hinds, 
> 1845).  In these cases of so-called didymous species pairs, it is not 
> entirely clear to me which is the ancestral and which the derived 
> condition, but, in a group taxonomically close to the Stocisia, Verduin 
> (1977) looked at European Rissoa species and concluded that the 
> lecithotrophic species was the descendant (apomorphic), and the 
> planktotrophic was ancestral (plesiomorphic).  Similar conclusions were 
> reached in a wider taxonomic and/or paleontological context in Ficus 
> (Smith, 1945), Trophon (Bouchet and Warén, 1985), Nassariidae (Martinell 
> and Cuadras, 1977), Neogastropoda in the early Tertiary and Volutidae in 
> the Cenozoic to Recent (Hansen, 1983), Terebridae (Bouchet, 1981), and 
> Turridae (Bouchet, 1990). To my knowledge, no instances of the opposite 
> pattern of evolution has been reported.  In fact, Strathman (1978) 
> concluded that plankotrophic development was ancestral to the 
> lecithotrophic condition among all marine invertebrates with such life 
> histories, and that the reversal of this process was much less frequent, 
> even unlikely. A relatively limited geographic distribution of 
> lecithotrophic species and their tendency to be less long-lived (in a 
> geological sense) than their planktotrophic congeners has been noted by 
> several workers including Jablonski (1982, 1986) and Hansen (1983)."
>
>Abstract:
>Rissoidae: Alvania auberiana (d'Orbigny, 1842) [planktotrophic]] vs. A. 
>faberi de Jong and Coomans, 1988 [lecithotrophic].
>Triphoridae: Iniforis turristhomae (Holten, 1802) [planktotrophic] vs. I. 
>casta (Hinds, 1845) [lecithotrophic].
>Cerithiopsidae: Retilaskeya emersonii (C. B. Adams, 1845) [planktotrophic] 
>vs. R. bicolor (C. B. Adams, 1839) [lecithotrophic].
>
>Although I work with this western Atlantic fauna a lot, I don't think I 
>can tell the latter two pairs apart without looking at the protoconch, and 
>even these two Alvania are quite a challenge thus deprived.
>
>Harry
>
>At 05:01 AM 10/13/2003, you wrote:
>>deal all
>>the theme of the evolution of larval development in marine invertebrates
>>has been my preferred one during several years. And it was the argument of
>>my very PhD thesis (1994). I have neglected it for a while but I'm still
>>accumulating data about several aspects. One of them is the phenomenon of
>>pais of species. I was thinking about presenting a poster to the next
>>UNITAS congress in Australia (2004).
>
>Cut to conform to UGa restriction
>---------------------------------------------------------------------------------------------------------------------------------------- 
>
>Harry G. Lee
>Suite 500
>1801 Barrs St.
>Jacksonville, FL 32204
>USA
>Voice: 904-384-6419
>Fax: 904-388-6750
><shells@hglee.com>
>Visit the Jacksonville Shell Club Home Page at:
>www.jaxshells.org
>
>oo .--.     oo .--.      oo .--.
>   \\(____)_ \\(____)_ \\(____)_
>     `~~~~~~ `~~~~~~ `~~~~~~

José H. Leal, Ph.D.
Director, The Bailey-Matthews Shell Museum
Editor, The Nautilus

P.O. Box 1580
Sanibel Island, FL 333957 USA
(239) 395-2233; fax (239) 395-6706
www.shellmuseum.org

"But fit the facts together in any other way and you get more nonsense 
instead of less."

Travis McGee in "The Green Ripper," as told to John D. MacDonald.

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