Abbottella (Abbottella) tenebrosa Watters, 2013, new species
Creators: name: Watters, G. Thomas
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Neotaenioglossa
Pomatiidae
Abbottella
Abbottella tenebrosa

description: Abbottella (Abbottella) tenebrosa new species
Figures 1 U–Y, 8 B
Type material. UF 456796, holotype; length, 7.6 mm; width, 8.9 mm. UF 456797, 15 paratypes; OSUM 37271, 12 paratypes; BMSM 17937, 16 paratypes; all from the type locality.
Type locality. Dominican Republic, Puerto Plata Province, El Choco, near Cabarete. ca. 19.74° N, - 70.42° W.
Other material examined. UF 456798, 12 immature or weathered specimens, from the type locality; GTW 7020b, 2 specimens, from the type locality.
Distribution and habitat. Known only from the type locality on limestone outcrops of El Choco.
Description. Shell large for genus (largest specimen, 8.6 mm total length x 10.1 mm maximum width; smallest specimen, 6.6 mm total length x 7.7 mm width; holotype, 7.6 mm total length including peristome x 8.9 mm total width including peristome), moderately high turbinate, whorls adnate except just before lip. Umbilicus wide, ca. 33% of total width, open to earliest whorls. Protoconch of 1.5–1.75 smooth, white or dark brown whorls with a white tip, but demarcation between protoconch and teleoconch not well-defined. Teleoconch of 2.75–3.0 whorls. Axial sculpture nearly obsolete, of numerous, crowded, low, microscopic lamellae, ca. 150 on last whorl. Spiral sculpture of ca. 50 low cords, occasionally of two sizes. Intersections of sculpture form nearly obsolete beads or scales. Whorls rounded with no indication of keels. Cords only slightly stronger in umbilicus. Suture narrowly, deeply channeled, finely serrate. Aperture double, circular (4.3 mm maximum width in holotype), adnate with final whorl. Inner lip smooth, barely exserted. Outer lip expanded, slightly narrower facing the umbilicus, somewhat undulating, consisting of numerous, fine, fused lamellae, with a prominent auricle fused to previous whorl; outer part of lip somewhat cup-shaped, inner part perpendicular to whorl. Shell uniformly dirty white to dark reddish brown, outer lip white, shell without bands except on lip. Rare specimens white on top of whorls, brown on bottom. Operculum multispiral with an oblique, cup-shaped calcareous lamella.
Variation in specimens. 58 specimens seen. Specimens vary in color from white to brown, with some individuals half white and half brown.
Comparison with other species. This species differs from A. sanchezi (Figure 4 J–N) and A. adolfi peninsularis (Figure 3 J–L) in having nearly obsolete sculpture and in lacking the prominent spiral cords delimiting the umbilicus. It differs from the adjacent A. mellosa (Figure 1 T) in its larger size and lack of prominent spiral cords in the umbilicus. It differs from A. dichroa in having obsolete sculpture and an oblique opercular lamella.
Etymology. L. tenebrosus, dark, gloomy, in reference to the shell color.
description: Published as part of Watters, G. Thomas, 2013, New taxa and distributional notes on Abbottella and related taxa (Gastropoda: Littorinoidea: Annulariidae), pp. 1-22 in Zootaxa 3646 (1) on page 8, DOI: 10.11646/zootaxa.3646.1.1, http://zenodo.org/record/283728