It seems the specimen from Rich's website is quite different from what we have on our photo gallery,
our shells are flatter, more trigonal and not as shinny. His shell seems to be a Pitar or
Transenella but I might be wrong.
http://www.femorale.com.br/shellphotos/detail.asp?species=Gouldia+cerina+%28C%2EB%2EAdams%2C+1845%29
Our shells were collected either at low tide using hand dredge or at 20-30 meters by dredge - from
Sao Paulo State to Espirito Santo State.
Marcus
________________________________________
De: Conchologists List [mailto:[log in to unmask]] Em nome de Harry G. Lee
Enviada em: quinta-feira, 2 de abril de 2009 11:26
Para: [log in to unmask]
Assunto: [CONCH-L] Gouldia cerina
Yo, Tom,
I now see there are 25 lots of Gouldia cerina and eight of G. cerina in my cabinet. A review of the
labels indicates no change in my reported limits of range, but bathymetrics vary from 0-39 m
(latter Bahamas) for Gouldia bermudensis and 0-66 m (latter Gulf of Mexico) for G. cerina.
G. cerina has a rounded subtrigonal shape (Marlo's images show this nicely), and G. bermudensis is
subcircular/oval and is less compressed. The beaks of G. b. are more blunt, tumid, prosocline and
anteriorly-placed than those of G. c. The radial sculpture is less effaced on the middle third of
the valves of G. b. G. b. appears to grow not much larger than 6 mm while G. c. often exceeds 10 mm.
Colors are more subdued in G. b. The pallial sinus of G. b. is very subtle; its inner margin is
nearly parallel to the pallial line, that of G. c. although small, has a quite distinctly arcuate
inner margin. Finally, the inner valve margins of mature G. b. have distinct fine commarginal sulci
(usually two) whereas, the inner margins of mature G. c. have less distinct commarginal sculpture
and are weakly crenulate.
The only illustration of G. bermudensis I can find is Dall and Stimpson (1901: pl. 55, fig. 2) their
type figure of G. insularis. In mixed Bermuda lots, shape alone allowed prompt and consistent
separation.
Harry
Dall, W. H. and C. T. Simpson. 1901. The Mollusca of Porto Rico. U. S. Fisheries Commission Bulletin
20: 351-524 + pls. 53-58.
At 07:48 AM 4/2/2009, Tom Watters wrote:
>So how does one separate G. cerina and G. insularis?
>At 07:46 AM 4/2/2009, I wrote:
>>Dear Allen and other interested parties,
>>
>>I mentioned an ex pisce series of Gouldia=20
>>cerina from 155 ft. off Ponte Vedra, St. Johns Co. on the discussion site.
>>
>>I have looked at a lot of Gouldia, including G.=20
>>bermudensis (E. A. Smith, 1885) [+ G. insularis=20
>>(Dall and Simpson, 1901], G. minima (Montagu,=20
>>1803), and G. californica Dall, 1917 - the=20
>>latter two occurring in the eastern Atlantic and E. Pacific respectively.
>>
>>In my collection are 18 lots of G. cerina=20
>>ranging from Bermuda to Brazil (Estado do S=E3o=20
>>Paulo) and six of G. insularis (Bermuda,=20
>>Bahamas, and Caribbean Colombia] - none from=20
>>the Carolinian Province. The two were found=20
>>together at only one place, Coney Is., Bermuda.
>>
>>I have been unable to distinguish any western=20
>>Atlantic species aside from these two. Their=20
>>bathymetric range seem to be similar. G. cerina=20
>>tends to appear closer to shore in the=20
>>"tropics" and is "submerged" in cooler waters.
>>
>>However, there is always more to any "just so" story as this.
>>
>>Harry
----------------------------------------------------------------------
[log in to unmask] - a forum for informal discussions on molluscs
To leave this list, click on the following web link:
http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
Type your email address and name in the appropriate box and
click leave the list.
----------------------------------------------------------------------
|
