Posted: Nov 27 2011

 Calliostoma jujubinum (Gmelin, 1791), Jujube Top-shell

11/27/11 Posted on Conch-L:

"First hand collecting information in Florida from the NE coast or panhandle would be welcome."

Member comments:


Leslie Crnkovic reported:

"I have a pair from Shell Island off Panama City I will try to locate and send you photos."

Peggy Williams responded indicating:

"In our area (SW Florida) we have C. tampaensis."


Ken Piech added:

"On Sanibel and Marco Islands, we find C. tampaensis. In the Keys we find C. jujubinum. Except for a slight color difference, which may not be all that different, the two species seem very similar to me. On several occasions I have shown my multiple lots of C. tampaensis and C. jujubinum to "others" and have asked them to explain to me the differences between these two species, but have not yet received any useful information. I would be delighted to see a presentation of these two species side by side."


 

 

 

 

Marlo: Here's a photo of a 24 mm C. tampaensis

(Conrad, 1846) from Tampa Bay, Florida, courtesy

of Olivier Caro:

 

 

 

 

Peggy responded to Ken's comment by suggesting:

"C. tampaensis is colored a little more yellowish than jujubinum, the periphery of the final whorl is more rounded (sharpish in jujubinum), and the texture of the shell is less polished - more nubbly (great scientific term, right?)"


Marlo: Note that Peggy's comment that the periphery of the final whorl is more rounded (sharpish in jujubinum) is why Ken feels the information distinguishing the two is not particularly "useful." It's not that Peggy's comment may not be valid (in her experience), but contrast her comment with Tucker Abbott's comment that C. tampaensis "is not always so swollen at its periphery."

Marlo then posted:

"Abbott indicated that C. jujubinum tampaensis “is possibly only a variant of jujubinum.” Although many seem to treat it as a separate species, I have treated all from the Florida west coast as C. jujubinum. From the photos I’ve seen of what some have called C. tampaensis, I believe only a good DNA analysis would persuade me these are separate species and not simply population variants where the C. tampaensis variant happens to be rather common on Florida’s west coast.

We’d certainly like to hear from those more expertise with these shells or live animal photos that display distinguishable differences."


Leslie Crnkovic offered:

"…jujubinum is considered an entire complex by some.
The best two works that cover western Atlantic Calliostoma are: (that I am aware of)
Quinn, 1992 - New Species of Calliostoma …notes on some poorly known species from the Western Atlantic, Nautilus 106(3):77-114.
Quinn, 1979 – Biological Results of the U Mi Deep sea Expeditions. 130……Trochidae…., Malacologia 19(1):1-62.


Harry Lee elaborated:

"Thanks, Leslie. Although there is nothing of relevance to our problem in Quinn (1972), which deals with the trochid fauna of the Continental Slope (180 m or more), the other Quinn reference gives us a little help with the taxonomic problem at hand.

Jim Quinn (1992: 93), in his discussion of Calliostoma scalenum new species, distinguished it from C. jujubinum by its "having shells which are larger and more narrowly conical; that have a slightly larger protoconch (320-325 vs. 315 mcm); that lack fine collabral threads after the fourth and fifth whorls; that have two rather than three distinct sizes of spiral cords with discrete, symmetrical rather than spirally-elongate beads, particularly on the base (35-42 vs. 25-30); and that lack very dark-colored apical whorls. Shells of C. scalenum are also similar to those of C. tampaense [note neuter termination] but differ by having straight-sided apical whorls that lack a strong, sharply beaded peripheral carina; by having finer, more numerous, and more finely beaded spiral cords; and by being proportionately much narrower. Both C. jujubinum and C. tampaense are also shallow water species, neither occurring alive in depths exceeding 11 m (Quinn, in press) ..." He goes on with a discussion of radulae.

The bibliography (Quinn,1992: 113) indicates that he had a paper "in press" [The Trochidae of the Gulf of Mexico (Prosobranch: Archaeogastropoda) Memoirs of the Hourglass Cruises]. Regrettably, this paper seems to have never gotten off the "press." Bill Lyons just told me the ms was completed, but the figures were sent back to the author to be redone, and apparently that was the end of it. This was to have been a very extensive taxonomic work - for instance there were to have been details on 200 lots of C. scalenum (Quinn, 1992: 93).

The types of all three taxa have been designated and figured (Chemnitz, 1781: pl. 167, figs. 1612, 1613; Clench and Turner, 1960: pl. 21, fig. 3; Quinn, 1992: figs. 43, 44).

We veterans of the FL scallop dumps have likely gotten plenty of the Carolinian C. scalenum (uniformly misID'ed as C. jujubinum before Quinn) but none of the other two taxa from that resource (Lee, 2009: 57). That's a starting point. It appears that, of the three, C. jujubinum is the only truly Caribbean species (including Palm Beach Co through the FL Keys). C. tampaense is apparently a Gulf of Mexico endemic.

While we must lament the lack of the Hourglass publication, I seem to have been able to parse out my specimens of these three taxa in my collection using only the above-quoted passage. If anyone can contact Jim Quinn, he might provide his view of this taxonomic problem."


Peggy commented:

"Jim Quinn in his exhaustive treatment of Calliostoma recognized tampaensis as a valid species."

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