Abbottella (Abbottella) nitens, Watters, G. Thomas, 2013

Watters, G. Thomas, 2013, New taxa and distributional notes on Abbottella and related taxa (Gastropoda: Littorinoidea: Annulariidae), Zootaxa 3646 (1), pp. 1-22 : 7

Abbottella (Abbottella) nitens new species

Figures 1 P–S, 5 R,S, 8 A

Type material. UF 456806, holotype; length, 7.7 mm; width, 7.8 mm. UF 456808, 15 paratypes, from the type locality.

Type locality. Dominican Republic, La Altagracia Province, 16 km S of Higüey, at 100 m. ca. 18.46° N, - 68.71° W.

Other material examined. UF 216167, 23 immature, broken, or weathered specimens, from the type locality.

Distribution and habitat. Known only from the type locality under rocks among boulders, on a limestone bluff west of Highway 4. Further collecting may show that it generally occurs along this bluff, which runs parallel to the Rio Yuma on the west, from the type locality to Boca de Yuma on the coast.

Description. Shell small (largest specimen, 8.5 mm total length x 8.6 mm total width; smallest specimen, 5.9 mm total length x 6.1 mm total width; holotype, 7.7 mm total length including peristome x 7.8 mm total width including peristome), turbinate, compact, whorls adnate. Umbilicus wide, ca. 30% of total width, open to earliest whorls. Protoconch of ca. 1.5 smooth whorls clearly demarcated from teleoconch. Teleoconch of 3–3.25 whorls. Axial sculpture of ca. 110 regularly spaced, low, fine lamellae, more widely spaced in umbilicus. Spiral sculpture of ca. 50 low, weak cords, slightly stronger in umbilicus. Intersections of axial and spiral sculpture form minute pustules or points, often nearly obsolete, elongated into blades at the suture but lamellae not fused. Suture very narrowly channeled, serrate. Aperture double, circular (3.7 mm maximum width in holotype), adnate with the auricle joining the final whorl. Inner lip smooth, slightly exserted. Outer lip narrowly, uniformly expanded, composed of numerous lamellae, auriculate. Base color of shell uniformly white or metallic tan or bronze, usually with very faint, tan spots arranged in ca. 6 spiral rows. Bands present on both sides of the outer lip. Sculpture the same color as the base except near the suture where the blades and a few rows of sculpture may be white; sculpture within the umbilicus may be white as well. Operculum multispiral with a calcareous lamella, arising obliquely then becoming vertical.

Variation in specimens. 39 specimens seen. Shells vary in color from brown to white; sculpture varies from minute pustules to being nearly imperceptible.

Comparison with other species. This species bears a striking resemblance to A. mellosa from Sósua ( Figure 1 T), from which it differs in its more rounded, capacious whorls and greater number of spiral cords (ca. 30 in A. mellosa vs. ca. 50 in A. nitens ). Both have the same obsolete sculpture and metallic sheen. However, A. nitens does not seem to be related to the other La Altagracia Province taxa, such as A. milleacantha ( Figure 3 X–BB), which are characterized by their small, compact shells and fine, prickly sculpture.

Remarks. Like other Abbottella from the eastern part of the island, numerous examples bear signs of predation. Most have been broken into on the dorsal side of the final whorl ( Figure 5 R). A few, including the holotype, have a small, circular hole bored through the shell ( Figure 5 S). Similar holes have been reported from other terrestrial snail shells and may be the result of predation by the larvae of drilid or lampyrid beetles (Harry, 1950). The holotype also has a web that nearly occludes the umbilicus ( Figure 1 R). Within the umbilicus was found a pseudoscorpion, family Olpiidae , subfamily Hesperolpiinae. The holotype was the only recently dead specimen (operculum still in place) and no such pseudoscorpion association was found in any of the other 42 specimens examined, which were all dead, mostly weathered specimens. It appears that the pseudoscorpion may have been commensal within the umbilicus of the live snail.

Etymology. L. niteo, shine, glitter, in reference to the metallic sheen of most specimens.

Figures

FIGURE 1. A – E. Abbottella (Abbottella) calliotropis new species. A – C. Holotype (UF 456810), 7.5 mm width. D. Paratype (UF 216131), 6.8 mm width. E. Paratype (UF 216131), 7.0 mm width. F – J. Abbottella (Abbottella) diadema new species. F – H. Holotype (UF 456814), 6.0 mm width. I. Paratype (UF 456815), 4.6 mm width. J. Paratype (UF 456815), 3.7 mm width. K – O. Abbottella (Abbottella) dichroa new species. K – M. Holotype (UF 456801), 9.9 mm width. N. Paratype (UF 216112), 8.8 mm width. O. Paratype (UF 216112), 9.4 mm width. P – T. Abbottella (Abbottella) nitens new species. P – R. Holotype (UF 456806), 7.8 mm width. Note pseudoscorpion web in umbilicus. S. Paratype (UF 456808), 8.3 mm width. T. Abbottella (Abbottella) mellosa Watters & Duffy, 2010. Holotype (UF 420729), 7.9 mm width. U – Y. Abbottella (Abbottella) tenebrosa new species. U – W. Holotype (UF 456796), 8.9 mm width. X. Paratype (OSUM 37271), 8.6 mm width. Y. Paratype (OSUM 37271), 8.3 mm width. Z – CC. Abbottella (Gundlachtudora) paradoxa new species. Z – BB. Holotype (UF 456812), 9.0 mm width. CC. Paratype (UF 456813), 8.9 mm width. DD. Abbottella (Gundlachtudora) bombardopolensis Bartsch, 1946. UF 33037, 7.0 mm width.

FIGURE 3. A – E. Abbottella (Abbottella) abbotti Bartsch, 1946. A – C. UF 215980, 5.6 mm width. D. UF 215983, 6.0 mm width. E. UF 215981, 5.2 mm width. F. Choanopoma adolfi Pfeiffer, 1852. Pfeiffer, 1854: pl. 48, fig. 8. G – I. Abbottella (Abbottella) cf. adolfi adolfi (Pfeiffer, 1852). GTW 7020 c, 5 mm width. J – L. Abbottella (Abbottella) adolfi peninsularis Bartsch, 1946. GTW 9430 a, 7.8 mm width. M. Abbottella (Abbottella) newcombi (Crosse, 1873). Syntype (MNHN 5436), 5.7 mm length. Photo courtesy of MNHN. N – R. Abbottella (Abbottella) aenea Watters, 2010. N – P. GTW 14181 a, 6.5 mm width. Q. GTW 14181 a, 6.1 mm width. R. Paratype (OSUM 35490), 6.0 mm width. S – W. Abbottella (Abbottella) crossei (Pilsbry, 1933). S – U. GTW 9432 a, 7.3 mm width. V. UF 216146, 7.6 mm width. W. UF 216146, 7.2 mm width. X – BB. Abbottella (Abbottella) milleacantha Watters & Duffy, 2010. X – Z. Holotype (UF 420728), 7.5 mm width. AA. Grego, 7.4 mm width. BB. Grego, 8.1 mm width.

FIGURE 5. A – F. Rolleia haitensis Bartsch, 1946. A – C. Holotype (USNM 504088), 12.0 mm width. Photo courtesy of USNM. D. UF 32777, 15.4 mm width. E. UF 32777, 13.7 mm width. F. UF 32863, 13.2 mm width. G – N. Rolleia oberi Watters & Duffy, 2010. G – I. Holotype (UF 434775), 10.3 mm width. J. UF 236228, 10.2 mm width. K. UF 216195, 11.0 mm width. L. UF 216195, 11.5 mm width. M. UF 216195, 10.7 mm width. N. UF 216195, 11.3 mm width. O. Abbottella (Abbottella) calliotropis new species. UF 216131, 7.1 mm width. Note predation damage. P. Abbottella (Abbottella) diadema new species. UF 215985, 5.0 mm width. Note predation damage. Q. Abbottella (Abbottella) dichroa new species. UF 216112, 8.3 mm width. Note predation damage. R, S. Abbottella (Abbottella) nitens new species. R. UF 216167, 7.9 mm width. Note predation damage. S. Holotype (UF 456806), 7.8 mm width. Note predation damage.