Sulawesidrobia marmer, Kadow & von Rintelen & Iqram & Bichain & Haase, 2025

Sulawesidrobia marmer sp. nov.

Etymology.

The word marmer is Indonesian and means marble. It refers to the shell’s appearance reminiscent of marble and is used as noun in apposition.

Material examined.

Holotype (Fig. 2 B View Figure 2 ): Indonesia • Sulawesi, North Konawe Regency, Lasolo, south of Abola, in a small stream next to the Wawotobi Road , on rocks. 3°43'06.6"S, 122°14'07.1"E. September 2023; Thomas von Rintelen, Muhammad Iqram, and Sara Nejad leg. MZB Gst. 12187 GoogleMaps .

Paratypes (Fig. 3 C, D View Figure 3 ): Indonesia • N = 15; same collection data as for holotype; MZB Gst. 12188 GoogleMaps . N = 15; same collection data as for holotype; ZMB 118347 View Materials GoogleMaps .

DIAGNOSIS. This new species has the conical shell shape and female genitalia seen in several species of Sulawesidrobia . But the translucent shell with its light-brown to whitish-grey appearance is characteristic. The coiled penis with the hook-shaped appendage pointing backwards is unique.

Description.

Shell. Conical, 1.6 to 1.7 times higher than wide, 3.625 to 4.5 whorls, sutures shallow, whorls moderately convex, transparent. light-brown to greyish, periostracum without colour (Figs 2 B View Figure 2 , 3 C, D View Figure 3 ); protoconch (N = 3) wrinkled with 0.8 to slightly more than 1 whorls (Fig. 4 B View Figure 4 ), teleoconch with growth lines, otherwise without structure; umbilicus narrow; outer lip straight.

Operculum (N = 2). Light orange, thin, paucispiral, nucleus eccentric.

External features (N = 2). General appearance fairly dark, black pigmentation particularly dense on snout, behind eyes, anterior parts of mantle and upper parts of whorls; eyes black; tentacles less dark with central white stripe; mirrored, sickle-shaped spots on pharynx; mantle almost unpigmented over distal genital glands in both sexes.

Mantle cavity (N = 2). Gill with 17–18 filaments almost abutting to pericard; osphradium elongate, about 2 / 5 of length of gill, behind middle of gill.

Digestive system (N = 2, for radula 1). Radula formula R: 4 1 4 / 1-2 1-2, L: 3 1 4, M 1: 15-18, M 2: 20-23; lateral tooth with solid junction between face and flank; stomach without caecum; rectum running along distal genital glands, less closely to prostate than to pallial oviduct.

Female genitalia (N = 1; Fig. 7 D, E View Figure 7 ). Ovary a simple sac, starting 1.5 whorls below apex, comprising 0.75 whorls, extending over proximal parts of stomach; renal oviduct undulating before final loop continuing into ventral channel; bursa copulatrix largely behind albumen gland, elongate-ovoid, bursal duct emerging anteroventrally; no receptaculum seminis, sperm storage in distal part of final oviduct loop; albumen gland milky-white, capsule gland opaque white.

Male genitalia (N = 1). Testis lobate, starting 1 whorl below apex, comprising about 1 whorl, overlapping proximal part of stomach; vesicula seminalis coiling underneath distal quarter of testis; penis coiling over neck, without pigment, distal part broadened before tapering to pointed tip, small hook pointing backwards on right side just behind broadening (Fig. 8 B View Figure 8 ).

Remarks.

The phylogenetic relationships are discussed in the Remarks to S. lasoloensis sp. nov. above.