Calliostoma gemmosum ( Reeve, 1842 )

Cavallari, Daniel C., Salvador, Rodrigo B., Dornellas, Ana P. S. & Simone, Luiz R. L., 2019, Calliostomatidae, Colloniidae, Margaritidae, and Solariellidae (Gastropoda: Trochoidea) collected by the Marion Dufresne (MD 55) expedition in southeastern Brazil, with description of a new species of Calliostoma, Zootaxa 4609 (3), pp. 401-428 : 403-404

Calliostoma gemmosum ( Reeve, 1842)

( Fig. 1 E–I)

Synonymy see Clench & Turner (1960) and Leal (1991). Complement:

Trochus gemmosus Reeve, 1842: 165 , pl. 218, fig. 9.

Calliostoma gemmosum: Kempf & Matthews, 1968: 91 , tab. I; Matthews & Kempf, 1970: 18; Leal, 1991: 45; Gomes et al., 2006: 185; Benkendorfer & Soares-Gomes, 2009: 147; Rios, 2009: 51, text fig.; Dornellas, 2012: 103, fig. 47.

Type material. Former Stainforth Collection, probably lost ( Clench & Turner, 1960).

Type locality. Not given, probably Western Atlantic ( Clench & Turner, 1960).

Previously known distribution. Probably endemic to Brazil, ranging from Maranhão state to Espírito Santo state, live specimens from 10–100 m ( Leal, 1991; Rios, 2009).

New occurrence. Vitória-Trindade Chain.

Habitat. Sandy bottoms.

Material examined. Brazil: Espírito Santo: off São Mateus, Abrolhos Slope , 18°49’S, 37°57’W, MD55 sta. DC83, 60 m, MNHN, 1 sh (28/v/1987) ; Vitoria Bank , 20°21’S, 36°59’W, MD55 sta. DC26, 97.5 m, MNHN, 1 sh (14/v/1987) ; Montague Bank , 20°25’S, 36°42’W, MD55 sta. DC27, 81 m, MNHN, 1 sh (14/v/1987) ; Jaseur Bank , 20°42’S, 35°22’W, MD55 sta. DC35, 15– 82 m, MNHN, 1 sh (16/v/1987) . Additional non-MD55 material: Brazil: Espírito Santo: off Guarapari , under rocks, 20–25 m, NMR 56382, 1 sh (xii/1991, ex coll. J.G.B. Nieuwenhuis) .

Measurements. 7 whorls, H=11.0 mm, D=11.0 mm (largest whole specimen).

Remarks. Reeve’s introduction of C. gemmosum in Conchologia Systematica included a single figure depicting a specimen in umbilical view ( Reeve, 1842: pl. 218, fig. 9). A complementary description published a year later

indicated the type locality as unknown ( Reeve 1843). No further detail was given and the type material is presumably lost. Nevertheless, subsequent works pointed out the Western Atlantic as the correct provenance of Reeve’s specimens ( Clench & Turner 1960). Although species identity is uncertain due to the absence of type specimens, there is little doubt that the Brazilian specimens depicted and referred to as C. gemmosum in the works published so far are part of a single, well-defined entity ( Clench & Turner, 1960).

Leal (1991) did not report this species among the MD55 material, but the present specimens compare well with Brazilian specimens described and illustrated so far (e.g., Rios, 1994, 2009). They also closely resemble specimens from museum collections examined here in outline, sculpture pattern and ground color. Curiously, the apex and the typical reddish-brown spiral stripes are much lighter in the MD 55 specimens ( Fig. 1 E–G). This could be due to post-mortem discoloration since the color is more vivid in juvenile specimens ( Fig. 1 H ). Based on the very few occurrences of C. gemmosum reported so far ( Matthews & Kempf 1970; Leal 1991), the present records expand the range of the species ca. 190 km south from 19°S to 20°42’S.

Figures

FIGURE 1. Calliostoma collected by the MD55 expedition. A–D. Calliostoma caribbechinatum. A. MNHN, sta. DC30, apertural view (H=6.4 mm, D=5.8 mm). B. same, apical view. C. MNHN, from Trindade Island, juvenile specimen, apertural view (H=1.9 mm, D=1.7 mm). D. MNHN, sta. DC43, detail of apex. E–I. Calliostoma gemmosum. E. MNHN, sta. DC83, apertural view (H=11.0 mm, D=10.9 mm). F. same, apical view. G. same, umbilical view. H. MNHN, sta. DC27, juvenile specimen, apertural view (H=3.3 mm, D=3.5 mm). I. MNHN, sta. DC26, detail of apex.