Callogaza watsoni Dall, 1881

Simone, Luiz Ricardo L. & Cunha, Carlo M., 2006, Revision of genera Gaza and Callogaza (Vetigastropoda, Trochidae), with description of a new Brazilian species, Zootaxa 1318 (1), pp. 1-40 : 22

Callogaza watsoni Dall, 1881

( Figs. 41–44 , 58–60 )

Callogaza watsoni Dall, 1881: 50 . Dall 1889: 356–357 (pl. 22, figs. 7, 7a; pl. 23, figs. 1, 1a; pl. 24,

figs. 2, 2a). Dall 1890: 342. Margarita filogyra Dall, 1881: 42 . Gaza (Callogaza) watsoni: Clench & Abbott 1943: 5 (pl. 2, figs. 3–4). Abbott 1974: 49 (fig. 377).

Rios 1975: 25 (pl. 6, fig. 71). Gaza watsoni: Clench & Aguayo 1940: 381 .

Types: Holotype MCZ 7544 (examined).

Type locality: CUBA, off Havana, 24º34’N 83º16’W, 324 m depth, (Blake Expedition, 1877) .

Diagnosis: Shell color pale beige with brown spots, spire low with about five whorls. Protoconch without hole in adult. Height/width 1.44 on average. Spire 0.60 of body whorl high. Umbilicus half covered by callus.

Distinctive description

Shell ( Figs. 41–44 , 58–60 ): discoid; spire low, height about 0.60 of body whorl height and about half its volume. Spire profile slightly concave, triangular dome­shaped; whorls convex, suture well marked; weak sub­sutural carina about 1/3 from upper suture in relation to total whorl width; surface between upper suture and carina horizontal, flat; between carina and lower suture a slope of minimally concave (almost straight) profile. Protoconch smooth, glossy, with about 2 whorls ( Figs. 42 , 60 ). Sculpture between upper suture, carina uniform reticulate; with spiral, curved axial lines equally developed, spaced; about 10 spiral lines. Sculpture between carina, lower suture composed almost exclusively of about 6 spiral cords, space between cords about 2–3 times their width. Sculpture between carina and umbilicus in body whorl with 18 spiral lines of uniform size, close to each other, axial lines well­marked in peri­umbilical area ( Figs. 43, 44 , 59 ), disappearing gradually from about 1/4 of lower body whorl surface; these axial lines having small notch at short distance from umbilicus, producing shallow spiral furrow surrounding umbilicus. Callus covering half of lower region of umbilical opening ( Figs. 43, 44 ), about 3 times broader in upper region than its lower region.

Measurement of shells (in mm): Holotype = 22.0 x 13.0.

Distribution: Caribbean Sea to north Brazil (off Pará).

Habitat: From 320 to 716 m depth.

Material examined: Holotype MCZ 7544 . BRAZIL; Ceará; off Fortaleza, 03° 22’00”S 37°49’00”W, 716 m depth, USNM 97116 , 1 shell ( R / V Albatross Sta. 2756, trawl, United States Fish Commission, 14/xii/1887, reported as “off Pará river ”).

Remarks: The specimen referred by Dall (1890: 342) from off Brazilian coast (off Fortaleza, Ceará) was re­examined ( Figs. 58–60 ). This material corresponds to a young (lacking callus), eroded and broken specimen. It has a taller profile than the holotype, but the remaining features including the shell sculpture do not differ from those of C. watsoni .

Figures

FIGURES 37–48. Shells. Figs. 37–40: Gaza rathbuni Holotype USNM 97054. Figs. 37–39: Shell in apertural, apical and umbilical views. Fig. 40: Detail of umbilical area; Diameter: 38 mm. Figs. 41–44: Callogaza watsoni Holotype MCZ 7544, a specimen with peristome not formed. Figs. 41–43: Shell in apertural, apical and umbilical views. Fig. 44: Detail of umbilical area; Diameter = 11 mm. Figs. 45–48: C. sericata MZSP 48530 from Aliguay, Philippines. Figs. 45–47: Shell in apertural, apical and umbilical views. Fig. 48: Detail of umbilical area. Diameter = 15 mm.

FIGURES 58–66. Shell and radulae in SEM. Figs. 58–60: Callogaza watsoni from off Pará, Brazil (specimen mentioned by Dall, 1889, USNM 97116): apertural, umbilical and apical views; diameter = 7.1 mm. Figs. 61–63: Gaza olivacea. Figs. 61–62: Central and lateral teeth. Fig. 63: Detail of lateral teeth; scale bars = 100 µm. Figs. 64–66: Gaza superba. Fig. 64: Entire shell; scale bar= 200 µm. Fig. 65: Detail of central and lateral teeth; scale bar = 100 mµ. Fig. 66: detail of lateral teeth; scale­bar = 100 µm.