Leiorhagium adioincola, Haase, Martin & Zielske, Susan, 2015

Haase, Martin & Zielske, Susan, 2015, Five new cryptic freshwater gastropod species from New Caledonia (Caenogastropoda, Truncatelloidea, Tateidae), ZooKeys 523, pp. 63-87 : 67-68

Taxon classification Animalia Littorinimorpha Tateidae

Leiorhagium adioincola sp. n.

Type material.

Holotype MNHN IM 2000-27860; paratypes MNHN IM 2000-27861 (29), NHMW 110182 (5).

Type locality.

NeCa 49, Poya: Massif d’Adio, stream flowing into Grotte d’Adio, open secondary forest, 21°15'24.4"S, 165°14'46.4"E, 29 May 2012.

Other material.

NeCa 43, Poya: small stream on W-side of road between Nétéa and Goipin, on forest edge, 21°16'06.0"S, 165°14'32.0"E, 28 May 2012, MNHN-IM-2012-36075 (23), NHMW 110183 (10).

Etymology.

Adioincola is composed of the name of the area of Adio and the Latin noun incola meaning inhabitant, and thus refers to the type locality of the new species.

Diagnosis.

Leiorhagium adioincola sp. n. is very similar to Leiorhagium kavuneva and Leiorhagium clandestinum sp. n. The former pair differs in penial shape, slender vs. basally broad with long terminal filament. Leiorhagium adioincola sp. n. tends to have fewer radular denticles than Leiorhagium kavuneva . Genetically, these species differed on average at 9.65% of the positions of COI. Due to the lack of anatomical data, both new species can only be distinguished genetically. Their COI sequences differed on average by 9.5% (p-distance).

Shell.

Pupiform, 1.8 times higher than wide, 4.125-4.75 whorls, without colour, transparent; protoconch faintly pitted with c. 1 whorl; palatal denticle a small droplet 1/8 whorl behind outer lip; aperture as high as wide (Figs 2B, 3C, D, 4C, D).

Operculum.

Elongate-ellipsoidal, paucisprial, nucleus submarginal, orange, usually two non-calcareous white pegs, eventually accompanied by a small third one (N=3) (Fig. 5C,D).

External features.

Epidermis without pigment, eyes black.

Mantle cavity.

Ctenidium with 18-19 (3 males) or 21-24 (2 females) filaments; osphradium kidney-shaped, behind middle of ctenidium.

Digestive system.

Radula formula (N=3) (Fig. 6B): R: 4 1 4/2 2, L: 4-5 1 6, M1: 22-27, M2: 21-29; stomach without caecum; rectum close to pallial oviduct in females and to prostate in males.

Female genitalia.

Ovary without lobes, proximal end 1.25 whorls below apex, comprising 0.25-0.5 whorls, eventually reaching stomach; anterior capsule gland yellow-orange, posterior capsule gland opaque-white, albumen gland milky-white; proximal loop of renal oviduct bent forward, distal loop short; bursa copulatrix almost cubical, reaching behind albumen gland; bursal duct long, entering anterior; no seminal receptacle (N=2) (Fig. 7B).

Male genitalia.

Proximal end of lobate testis 1.25-1.5 whorls below apex, comprising 0.5-0.75 whorls, covering proximal end of stomach; vesicula seminalis arising from anterior half of testis; penis slender, terminal end occasionally forming short filament (N=3) (Fig. 8C).

Remarks.

This is Leiorhagium sp. n. 4 of Zielske and Haase (2015). Leiorhagium adioincola sp. n. occurs in the area between the villages of Nétéa and Goipin including the Massif d’Adio.