Posted: Sep 7 2009
Chicoreus dilectus (A. Adams, 1855), Lace Murex
The following discusison occured on Conch-L regarding differences between C. florifer and C. dilectus:
John Wolffe offered:
"Quoting Emily Vokes in Tulane Studies 3:(4)194 (1965):
'C. florifer, although similar to C. dilectus, may be distinguished from that species by its larger average size and heavier shell. It also has one longer spine at the shoulder and generally more imbricated spines. There is only one intervarical node which is much stronger than that of C. dilectus and the shell is proportionally wider at the periphery, giving it a triangular aspect. The shell is darker in color, ranging from a pale yellow body with dark brown fronds as shown by Reeve, to a completely dark brown shell such as the one figured by Kiener, as Murex rufus'
C. florifer is discussed further in Tulane Studies 23:(1-3) p.32 (1990)
Whether or not to use subspecies in nomenclature is a separate issue. At the risk of misquoting her, Emily felt that the requirements for naming a subspecies - describable and consistent differences plus a non-overlapping range (bathymetric or geographical), made little difference from the definition of a species and you might as well call it that."
Andrew Grebneff focused in on John's comment regarding Vokes' comments about using subspecies:
"That's right. If there are consistent differences, then there is no reason not to differentiate them as species. If the differences are not consistent, and intergrades occur, then there is either only one species (the norm) or hybridization is going on.
Distribution isn't necessary to take into account; distinct but similar forms can be sympatric (living together in the same environment) or allopatric (distributions not overlapping; allopatry can be either geographic or environmental; in the latter two species can live within meters of one another, but not actually be found together... except where the boundaries of their environments are in contact)."
Steve Rosenthal, upon reviewing the photos wrote:
"Hi Marlo, saw the first installment of your latest great feature. Did you get any BIG Murex in Eleuthera, ie in the 3 inch range? I think the big Bahamas florifer with longer spines and triangular shape indeed make it easier to see the differences alluded to in the Vokes description. I believe all your Eluethera pics are small "true" florifer, and the rest (all from FLA) will be "dilectus" (whether form or subspecies or distinct species).
Marlo's note: I've never collected this shell myself. Jim Cordy provided some large florifer from the Bahamas for examination.
So, using Vokes' characters, C. florifer differs by:
1. Larger average size and heavier shell.
2. One longer spine at the shoulder
3. Generally more imbricated spines
4. Only one intervarical node which is much stronger than that of C. dilectus
5. Proportionally wider at the periphery, giving it a triangular aspect
6. Darker in color, ranging from a pale yellow body with dark brown fronds as shown by Reeve, to a completely dark brown shell
And, using John's interpretation of Vokes' comments on speciation as concurred upon by Andrew, if the above six characters "are consistent differences," esp. if the two are sympatric (sharing the same territory), then we can assert that separate species are involved. However, the two do not appear to share the same territory and absent a DNA analysis, I don't beleive we can yet assert that these two shells are indeed sparate species. One may well be a geographically separated variation of the same species.
3/3/16 Rusty posted:
Rare intact on treasure coast usually not as frilly as pictures above. Broken ones even rarer for some unknown reason. Often not easily beached by the ocean, kept in splash zone.