Xestoleberis

Luz, Nathália Carvalho Da & Coimbra, João Carlos, 2015, The genus Xestoleberis (Ostracoda: Xestoleberididae) in the Northern, Northeastern and Eastern regions of the Brazilian continental shelf, Zootaxa 3974 (2), pp. 177-195 : 193

Xestoleberis sp.

Fig. 6 : 12–14

2008 Xestoleberis sp. 2 Machado, p. 128, pl. 5, figs. 20–21, pl. 6, fig. 1, tab. 6.

Figured specimen. MP-O-1898.

Locality. REMAC/Leg 7—Sample 3791 (12º14’S / 37º35’W); depth: 37 m; sediment: biodetritical sand. Material. 5 adult females and 2 juveniles.

Dimensions. See table 6.

Material Length (mm) Height (mm) Width (mm) MP-O-1698 (carapace) RV: 0.46 RV: 0.21 0.28 LV: 0.47 LV: 0.24

Description. A medium-sized and moderately thick-shelled species of Xestoleberis . In lateral view, RV subrectangular and elongate; LV sub-ovate and elongate. In dorsal view, sub-ovate and quite inflated. Ventral surface strongly flattened. LV overlapping RV along dorsal, anterior and posterior margins. Maximum length very close to ventral margin. Maximum height at mid-length. Maximum width in posterior third. In RV, anterior margin obliquely pronounced and narrowly rounded ventrally; posterior margin obliquely sloping, somewhat pointed ventrally. Dorsal margin somewhat straight and sloping backward; ventral margin almost straight. In LV, anterior margin obliquely pronounced and narrowly rounded; posterior asymmetrically rounded. Dorsal margin convex; ventral margin convex and somewhat sinuous. Surface typically smooth, with lip-type normal pore canals (sensu Sato & Kamiya 2007). Eye-spot inconspicuous. Xestoleberis -spot conspicuous and long. Hinge hemimerodont, with crenulate terminal teeth in RV and median element smooth. Adductor muscle scars a row of four sub-elliptical spots. Frontal scar not well-defined.

Remarks. Xestoleberis sp. is a very rare species. In the present paper only seven specimens, consisting of five female adults and two juveniles, were found, hindering a more detailed morphological and taxonomic study. The specimens figured by Machado (2008) represent males of this species.

Occurrence and distribution. Xestoleberis sp. occurs along the Northeastern and Eastern regions of the Brazilian continental shelf ( Fig. 2 ; Tab. 1), between 20 and 79 m of depth.

Figures

FIGURE 2. Distribution of Xestoleberis species in Brazilian continental shelf. The hatched area corresponds to the Transitional Zone of Coimbra et al. (1995). Each dot represents one sample.

FIGURE 6. 1 – 11. Xestoleberis virilis sp. nov. 1. Female, RV (MP-O- 1816). 2. Female, LV (MP-O- 1816). 3. Male, dorsal view (MP-O- 1814, holotype). 4. Male, Carapace, RV (MP-O- 1814, holotype). 5. Male, LV (MP-O- 1815). 6. Male, ventral view (MP-O- 1814, holotype). 7. Xestoleberis - spot (MP-O- 1816). 8. Simple-type normal pore canal (MP-O- 1816). 9. Central muscle scars, LV (MP-O- 1815). 10. Hinge (MP-O- 1816). 11. Schematic drawing of some internal features. 12 – 14. Xestoleberis sp. 12. Carapace, RV (MP-O- 1698). 13. Carapace, LV (MP-O- 1698). 14. Carapace, dorsal view (MP-O- 1698).