Diplopoma turritum (Pfeiffer, 1852)

Watters, G. Thomas, 2014, A revision of the Annulariidae of Central America (Gastropoda: Littorinoidea), Zootaxa 3878 (4), pp. 301-350 : 345-347

Diplopoma turritum (Pfeiffer, 1852)

Figure 11 G–H

Type material.? NHMUK unnumbered (1), from Cuming collection bearing Pfeiffer’s handwriting labeled “Dyson, Honduras,” but does not match figure in Pfeiffer (1854a) (see Remarks);? UMMZ 77930 (1), syntype.

Type locality. “ Honduras.”

Type figured. Pfeiffer, 1854a: pl. 41, figs. 1, 2.

Chresonymy.

Chondropoma ? turritum Pfeiffer, 1851: 173 [nomen nudum].

Chondropoma ? turritum Pfeiffer, 1852a: 289 ; Pfeiffer, 1852c: 45; Pfeiffer, 1865: 153; Bland, 1866: 61; Pfeiffer, 1876: 195; Watters, 2006: 525 –526.

Cyclostomus turritum (Pfeiffer, 1852) . Pfeiffer, 1852d: 69.

Cyclostoma turritum (Pfeiffer, 1852) . Pfeiffer, 1853b: 248; Pfeiffer, 1854a: 310, pl. 41, figs. 1, 2; Pfeiffer, 1854b: 310.

Chondropoma turritum Pfeiffer, 1852 . Adams & Adams, 1856: 296; Reeve, 1863a: pl. 7, fig. 52; Martens, 1890: 19 –20; Solem, 1961: 204, 207, pl. 11, fig. 22, map 2; Thompson, 2011: 47 [possibly West Indian].

Cistula turritum (Pfeiffer, 1852) . Fischer & Crosse, 1890: 218.

Gouldipoma turritum (Pfeiffer, 1852) . Watters, 2006: 72, 525–526.

Distribution and habitat. Unknown. Not reported since description.

Description. Shell conic, high-spired, adnate. Only specimen seen 13.2 mm in length (decollate). Protoconch unknown, lost in adult. Teleoconch of 5.25 rounded whorls. Umbilicus narrow. Spiral sculpture of ca. 35 regularly spaced, low threads of equal thickness from suture into umbilicus. Axial sculpture of numerous closely spaced threads, slightly thicker than the spiral threads. Intersections of axial and spiral sculpture minutely beaded. Suture strongly indented. Tufts absent but every other axial thread is slightly expanded at the suture. Aperture oval. Inner lip absent. Outer lip narrowly expanded, very narrow facing umbilicus, adnate, scarcely auriculate posteriorly. Colored with a complex pattern, base color tan, axial threads white, with ca. 7 broken, narrow tan bands which extend to adapertural face of peristome. Operculum, radula, and anatomy unknown.

Variation in specimens. Only the UMMZ specimen was examined.

Comparison with other species. This species resembles no other Central American annulariid.

Remarks. The NHMUK specimen, collected by Dyson, does not closely match Pfeiffer’s 1854 figures. In addition, the specimen is accompanied by an operculum, but in the original description it is clear that Pfeiffer did not have a specimen with an operculum.

Thompson (2011) suggested that this species was actually Parachondria canescens (Pfeiffer, 1852) , a Cuban species, that had been introduced. Examination of the UMMZ specimen indicates that it is probably Diplopoma arangiana ( Pfeiffer, 1857) from eastern Cuba, and is probably a mislabeled specimen. (If so, Chondropoma turritum Pfeiffer, 1852 , would be the earliest name for that species.)

Nevertheless, related Cuban species have turned up in some far flung places. Parachondria canescens occurs at Nassau, Bahamas, which Bartsch (1946) named subspecies nassauense, while admitting that it had possibly been introduced. It also occurs near Freetown, Eleuthera, Bahamas (Watters, unpubl.). The Hispaniolan species Parachondria salleanus ( Pfeiffer, 1850) occurs on Sombrero Island in the British Virgin Islands (Watters, in press). All of these places experience a great deal of human traffic (Sombrero Island was mined for guano and was visited on a regular basis by ships and workers, Nassau and Eleuthera are popular destinations). These records undoubtedly are anthropogenic introductions but it is suspicious that they all involve two related species.

Original description (translated here from Latin). “Shell nearly perforate, turreted, truncate, with elevated spiral lines and regular longitudinal ribs, white, banded with interrupted red lines; suture rather deep, with crowded denticulations; remaining 6 whorls slightly convex, regularly increasing, last rounded, base with strong spiral lirae; aperture vertical, oval, brown inside; peristome double: inner continuous, a little expanded, outer with top expanded angulate, right margin slightly expanded, columella and left cut.—Operculum?” 16 mm.

Etymology. L. turritus —turreted.

Figures

FIGURE 11. A – C. “ Choanopoma ” cygni Pilsbry, 1930. ANSP 150938, holotype, 6 mm width, photo courtesy of ANSP. D – F. Annularisca pleurophora (Pfeiffer, 1852). UMMZ 79565, 8.2 mm. G – H. Diplopoma turritum (Pfeiffer, 1852). UMMZ 77930, 13.2 mm.