Abbottella (Abbottella) tenebrosa, 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 : 8

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.

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 4. A – E. Abbottella (Abbottella) rosaliae (Pfeiffer, 1858). A – C. UF 216191, 9.2 mm width. D. UF 216135, 9.9 mm width. E. UF 216125, 9.3 mm width. F – I. Abbottella (Abbottella) samanensis Bartsch, 1946. F – H. GTW 7085 c, 8.7 mm width. I. GTW 7085 d, 8.0 mm width. J – N. Abbottella (Abbottella) sanchezi Bartsch, 1946. J – L. UF 216154, 9.1 mm width. M. UF 216154, 8.1 mm width. N. UF 216154, 7.6 mm width. O – S. Abbottella (Abbottella) sosuaensis Bartsch, 1946. O – Q. UF 218136, 6.9 mm width. R. UF 218136, 7.7 mm width. S. GTW 9431 a, 7.6 mm width. T – X. Abbottella (Abbottella) wilhelmi (Pfeiffer, 1858). T – V. UF 216150, 8.5 mm width. W. UF 216150, 8 mm width. X. UF 216150, 7.6 mm width. Y – CC. Lagopoma lagopoma Bartsch, 1946. Y – AA. GTW 10081 a, 9.7 mm width. BB. GTW 10081 a, 7.6 mm width. CC. UF 216120, 7.7 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.