Parachondria (Chondropomorus) trachydermus ( Pilsbry, 1933 )

Watters, G. Thomas, 2016, Review of the Hispaniolan Parachondria (Chondropomorus) complex (Gastropoda: Littorinoidea: Annulariidae), Zootaxa 4127 (2), pp. 245-275 : 258-259

Parachondria (Chondropomorus) trachydermus ( Pilsbry, 1933)

Figures 2 AC–AI, 5 B

Type material. Chondropoma petitianum var. costata Weinland, 1880 : not located. Weinland stated “Legit Newcomb. Communic. el. Bland.” Chondropoma trachyderma Pilsbry, 1933 : ANSP 7872a, holotype; ANSP 373754(1), paratype. Chondropoma petitianum dominicum Bartsch, 1946 : NMNH 493309, holotype.

Type locality. Chondropoma petitianum var. costata Weinland, 1880 : “St. Domingo.” Chondropoma trachyderma Pilsbry, 1933 : “Santo Domingo.” Chondropoma petitianum dominicum Bartsch, 1946 : “Puerto Plata.”

Figured type. Chondropoma petitianum var. costata Weinland, 1880 : unfigured. Chondropoma trachyderma Pilsbry, 1933 : Pilsbry, 1933: pl. 6, fig. 10. Chondropoma petitianum dominicum Bartsch, 1946 : Bartsch, 1946, pl. 2, fig. 6.

Cresonymy.? Chondropoma petitianum var. costata Weinland, 1880: 346 ; Watters, 2006: 399.

Chondropoma trachyderma Pilsbry, 1933: 123 , pl. 6, fig. 10; Bartsch, 1946: 19 [in synonymy of Chondropoma petitianum var. costata Weinland, 1880 ]; Baker, 1964: 170; Watters, 2006: 518 [in synonymy of Chondropoma petitianum var. costata Weinland, 1880 ].

Chondropoma (Chondropomorus) trachyderma Pilsbry, 1933 . Clench & Aguayo, 1937: 66.

Chondropoma (Chondropomorus) petitianum dominicum Bartsch, 1946: 18 –19, pl. 2, fig. 6; Ruhoff, 1973: 63; Watters, 2006: 46.

? Chondropoma (Chondropomorus) petitianum costatum Weinland, 1880 . Bartsch, 1946: 19, pl. 2, fig. 4.

Parachondria (Parachondria) petitianus dominicus ( Bartsch, 1946) . Watters, 2006: 46, 400.

? Parachondria (Parachondria) petitianus costatus ( Weinland, 1880) . Watters, 2006: 46, 399.

Distribution and habitat. Known from the coast, the northern slopes, and the associated plain of the Cordillera Septentrional from Puerto Plata east to the Samaná Peninsula and off the coastal plain into the mountains to ca. 900 m at El Puerto and Pico Isabel del Torres. Found under limestone rubble, on mogotes, and on limestone cliffs in karst areas of humid, mesic forests and ravines; these are evergreen forests in the higher altitudes. One record of arboreal habitat. Portions of the range have been cleared for coffee, cocoa groves, and pastures but other areas are in protected regions (e.g., Parque Nacional Isabel del Torres). Occasionally common.

Material examined (385 specimens). Dominican Republic. UF 216738(3), 50 m, 9 km WNW of Puerto Plata, Puerto Plata Province; UF 216708(15), 470 m, 4 km W of El Cupey, Puerto Plata Province; UF 119143(21), Puerto Plata, Puerto Plata Province; GTW 7072e(3), 610 m, 8 km S of Puerto Plata, Puerto Plata Province; GTW 7072d(13), 760–900 m, La Has, El Puerto, Puerto Plata Province; UF 216713(10), 790 m, Pico Isabel del Torres, Puerto Plata Province; UF 216736(7), Loma Blanca, 3 km N of Madre Vieja, Puerto Plata Province; UF 216735(7), 700 m, Loma del Puerto, Lajas de Yaroa, Santiago Province; UF 216743(12), 800 m, Loma El Indio Vieja, 7 km SSW of Yásica Abajo, Santiago Province; UF 216741(9), Loma Diego de Ocampo, Santiago Province; UF 216714(9), 50 m, 6 km SE of Sosúa, Puerto Plata Province; UF 45878(1), 7 km E of Sosúa, Puerto Plata Province; UF 216719(2), 135 m, 7 km SSE of Sosúa, Puerto Plata Province; UF 216723(1), 135 m, 3 km NW of Balneario de Catalina, Loma Catalina , Puerto Plata Province; UF 216716(1), 260 m, Loma Catalina, 11 km SSE of Sosúa, Puerto Plata Province; UF 216722(2), 600 m, Lajas de Yaroa, Santiago Province; UF 216732(19), 30 m, 3 km NE of Jamaó al Norte, Espaillat Province; GTW 7072a(2), Río San Juan, Espaillat Province; GTW 7072f(5), 30 m W of RD 5, Río San Juan, Espaillat Province; UF 216730(1), 30 m, 7 km WSW of Río San Juan, María Trinidad Sánchez Province; UF 216715(1), 1 km NE of Río San Juan, María Trinidad Sánchez Province; UF 216737(1), 8 km ENE of Río San Juan, María Trinidad Sánchez Province; UF 216712(3), UF 216725(14), 30 m, 3 km NW of “Cabral” [possible error for Cabrera?], María Trinidad Sánchez Province; UF 216709(3), 20 m, 10 km WNW of “Cabral” [possible error for Cabrera?], María Trinidad Sánchez Province; OSUM 6755(72), Caño Azul Colorado, María Trinidad Sánchez Province; UF 21671(6), 18 km SE of Río San Juan, María Trinidad Sánchez Province; UF 216632(34), 30 m, 0.5 km NNE of Cayo Clara, María Trinidad Sánchez Province; UF 216745(3), 1 km NW of Arenoso, Duarte Province; UF 216734(17), 2.9 km NE of Sánchez, Samaná Province; UF 216636(4), 250 m, 5 km ENE of Sánchez, Samaná Province; UF 216633(4), 5 km E of Sánchez, Samaná Province; UF 216635(1), 330 m, 10 km SW of Las Terrenas, Samaná Province; UF 216634(4), 9 km E of Las Terrenas, Samaná Province; UF 216638(8), sea level, 10 km E of Las Terrenas, Samaná Province; UF 216726(7), 270 m, 40 km NE of Sánchez, Samaná Province; UF 216742(1), 4 km E of Samaná, Samaná Province.

Redescription. Shell solid, opaque, high-spired, elongate conic. Maximum adult size: 17.2 mm, decollate. Minimum adult size: 11.3 mm, decollate. Adult shell decollated, protoconch of 1.5 minute, smooth, rounded, tan whorls. Teleoconch with 5–5.25 remaining whorls in decollated shells. Axial sculpture of final whorl of numerous (ca. 80–90) fine to coarse threads separated by more than their width. Shell with regularly spaced growth stoppage marks, axial threads preceding marks often much smaller and more densely packed. Spiral sculpture of final whorl outside of umbilicus 20–25 threads of various thickness. Overall sculpture clearly fenestrate. Umbilicus bounded by 2–4 weak cords, smooth within. Suture very narrow, not channeled. Tufts composed of 1 (less commonly 2) enlarged axial thread aligned with each growth mark. Aperture oval, lip double. Inner lip weakly expanded, exserted. Outer lip evenly expanded, narrower facing umbilicus; adnate with previous whorl. Lamellate, posterior auricle weak. Color pattern complex and variable. Base color tan, dark brown, or olive. Growth marks with axially aligned faint tan zig-zag marks, absent on darker specimens. 2–3 more or less continuous brown bands bounding umbilicus. Tufts and sculpture white. Inner lip and adapertural face of outer lip orange, yellow, or cream. Both lips with prominent dark bands on both faces. Inner rim of aperture often lined with orangish or dark brown. Operculum corneous, paucispiral, lacking calcareous granules.

Variation in specimens. Specimens vary in sculpture strength with those from eastern populations having the coarsest surface. Individuals vary considerably in adult size within a population.

Comparison with other species. The sculpture is coarser than that found in the similar high-spired P. gnotus and P. petitianus (only ca. 80–90 axial threads in P. trachydermus ,>120 axial threads in those two species). This species resembles P. silvaticus , which has less distinct sculpture and fewer axial and spiral threads. It is perhaps most similar to the Haitian P. a rci s e ns i s, differing primarily in its slightly coarser, less polished sculpture. Nevertheless the two are very similar in most characteristics but are separated by ca. 130 km and occur on different mountain ranges.

Remarks. Populations in the eastern part of the range from María Trinidad Sánchez Province into the Samaná Peninsula have coarser sculpture than do western populations. These coarsely sculptured specimens were the basis of C. trachyderma whereas the smoother western specimens were the basis for C. dominicum . They form part of a continuum and represent extremes of a single species.

Weinland’s and Pilsbry’s descriptions of their taxa only mentioned Santo Domingo as the type locality, a term that could refer to either the city or the entire island. Bartsch, without comment (1946, followed uncritically by Watters, 2006), synonymized Pilsbry’s species with that of Weinland and identified specimens from the Samaná Bay area as this taxon. Weinland’s species has never been figured and the type has not been located. The entire description consisted only of “ Costis spiralibus validioribus.” This is certainly insufficient to accurately identify Weinland’s species and Chondropoma petitianum var. costata Weinland, 1880 , is here regarded as a nomen dubium pending the discovery of the type (s).

Original descriptions. Chondropoma petitianum var. costata Weinland, 1880 : see Remarks above.

Chondropoma trachyderma Pilsbry, 1933 : see Pilsbry (1933: 123).

Chondropoma petitianum dominicum Bartsch, 1946 : Bartsch (1946: 19). “This race, which comes from the region of Puerto Plata, Dominican Republic, and the coast line east to Sosúa, is distinguished from the other members of the closely spaced, axially ribbed forms by having the umbilicus comparatively broad.”

Etymology. Chondropoma petitianum var. costata Weinland, 1880 : L. costatus, ribbed. Chondropoma trachyderma Pilsbry, 1933 : Gr. trachys, rough + Gr. derma, skin. Chondropoma petitianum dominicum Bartsch, 1946 : Dominican Republic.

High-spired taxa (spire ca 1.5 times length of aperture or less), flaring double lip

Figures

FIGURE 2. A – H. Parachondria (Chondropomorus) gnotus (Pilsbry, 1935). A. Chondropoma soror Pilsbry, 1933, holotype, ANSP 44344 a, ca. 13.5 mm. B. Chondropoma gnote kriegeri Bartsch, 1946: NMNH 471997, holotype, 13.5 mm. C, D. UF 216404, 13.5 mm. E. UF 216404, 12.8 mm. F. UF 216392, 15.1 mm. G. UF 216404, detail of spire. H. UF 216404, detail of suture.