Gaza compta Simone & Cunha, 2006

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 : 416

Gaza compta Simone & Cunha, 2006

( Fig. 6 G–I)

Gaza compta Simone & Cunha, 2006 : 4 , figs 1–10, 49–52, 67–77, 92.

Type material. Holotype: MZSP 40324 . Paratypes: MZSP 40325 , 5 spm; ANSP 413312, 1 sh; MNRJ 10531, 1 sh; ZSM 20060173, 1 sh, all from type locality .

Type locality. Brazil, Rio de Janeiro, off Cabo Frio , 22º53’S 42º01’W, 700–800 m depth (otter trawl, i/2004. C.M. Cunha leg.) .

Previously known distribution. Known only from type locality, 800–900 m (live specimens).

New occurrence. Off Espírito Santo, Abrolhos Slope, down to 940 m depth (shells only).

Material examined. Additional material: Brazil: Espírito Santo: off São Mateus, Abrolhos Slope , 18°59’S, 37°48’W, MD55 , sta. DC73, 607– 620 m, MNHN, 1 sh (27/v/1987); 19°36’S, 38°53’W, MD55 sta. CB 93, 640 m, MNHN, 1 sh (30/v/1987); 19°40’S, 37°48’W, MD55 sta. CB77 , 790– 940 m, MNHN, 1 sh (27/v/1987). Additional non-MD55 material : Brazil: Rio de Janeiro: holotype .

Measurements. ~5¾ whorls, H= 10.2 mm, D= 14.1 mm (largest juvenile specimen).

Remarks. The MD 55 specimens are all juvenile and fragmentary but retain enough conchological features to allow identification, such as the faintly purple-colored initial teleoconch whorls that also show well-marked axial undulations, the overall shell profile, and the compatible height/width ratio (~1.45 according to Simone & Cunha 2006). The new records from the MD55 expedition presented herein are the first published since the original description and expand the range of the species ca. 470 km to the north. The bathymetric range is also expanded from the previously known maximum depth of 800 m to 940 m.

Figures

FIGURE 6. Margaritidae collected by the MD55 expedition. A–F. Callogaza watsoni. A. MNHN, sta. CB77, spm #1, apertural view (H=6.0 mm, D=8.0 mm). B. MNHN, sta. DC75, under SEM, apical view (D=6.7 mm). C. MNHN, sta. CB77, spm #2, under SEM, umbilical view (D=6.2 mm). D. MNHN, sta. DC75 under SEM, detail of apex. E–F. MNHN, sta. SY74, juvenile specimen (H=1.6 mm, D=2.3 mm). E. apertural view. F. apical view. G–L. Gaza compta. G–I. MNHN, sta. CB77, juvenile specimen (10.2 mm, D=14.1 mm). G. apertural view, H. apical view. I. umbilical view. J–L. MNHN, sta. CB93, juvenile specimen #1 (H=1.7 mm, D=2.7 mm). J. apertural view. K. apical view. L. detail of apex under SEM.