Rhagada setzeri atauroensis, Köhler, 2014

Köhler, Frank, 2014, On the land snail Rhagada Albers, 1860 (Gastropoda: Camaenidae) from across the Lesser Sunda Islands, Raffles Bulletin of Zoology 62, pp. 115-123 : 120

Rhagada setzeri atauroensis n. subsp.

( Figs. 1C, D , 2C )

Type locality. Timor-Leste, Atauro Island , 2.6 km NW of Beloi, 8° 12' 08.3" S, 125° 35' 31.9" E .

Holotype. AM C.478282 (dissected specimen, wet, shell destroyed).

Paratypes. AM C.468712 (type locality, 23 wet), AM C.468711 (near Makadade , 8° 12' 42.3" S, 125° 34' 54.9" E, 20 wet, 5 dry) , AM C.468709 (northern tip of Atauro , 8° 07' 56.3" S, 125° 37' 59.4" E, 7 wet, 8 dry) , AM C.470222 (2.6 km NNW of Beloi , 8° 12' 30.3" S, 125° 36' 19.9" E, 4 dry) .

Etymology. Named for Atauro Island.

Description. Shell moderate in size (D = 13–19 mm; Table 1 ), with faint to well-developed axial ribs, umbilicus forming a chink or narrowly open. Penial verge with circular folds, penial wall with weakly developed longitudinal pilasters, epiphallus with short flagellum ( Fig. 2C ).

Comparative remarks. Differs from the nominate form by smaller shell, weaker ribs, more vivid colouration, not completely closed umbilicus. Both island forms are separated by comparatively low genetic distances of about 4% in COI and 2% in 16S ( Table 2 ). Because low genetic differentiation might indicate incomplete reproductive isolation, the Atauro Island populations are described as a subspecies of R. setzeri rather than being recognised as a full species. Rhagada setzeri is well-differentiated from R. solorensis and R. abbasi n. sp. by means of genetic distances of 12–16% in COI and 8–9% in 16S.

Figures

Fig. 1. Shells (1.5× of natural size). A, Rhagada solorensis, Solor Island, AM C.471154; B, Rhagada setzeri setzeri, Alor Island, AM C.471156; C, D, Rhagada setzeri atauroensis n. subsp., Atauro Island: C, Paratype AM C.468711; D, Paratype AM C.468709; E–H, Rhagada abbasi n. sp., Lembata Island: E, Holotype AM C.478280; F–H: Paratypes AM C.471153, showing variation in sculpture and colour pattern. Scale bar = 10 mm.

Fig. 2. Penial anatomy, with penial chamber opened showing internal anatomy. A, Rhagada solorensis, Solor Island, AM C.471154; B, Rhagada marghitae, Nusa Penida AM C.327851; C, Rhagada setzeri atauroensis n. subsp., Atauro Island, holotype AM C.478282; D, Rhagada abbasi n. sp., Lembata Island, holotype AM C.478280. Abbreviations: ep = epiphallus; fl = epiphallic flagellum; gp = genital pore; lwp = longitudinal wall pilaster; pv = penial verge; rm = penial retractor muscle; va = vagina; vd = vas deferens. Scale bars = 2 mm.