Hemistomia andreae, 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 : 65-66

Taxon classification Animalia Littorinimorpha Tateidae

Hemistomia andreae sp. n.

Type material.

Holotype MNHN IM 2000-27858; paratypes MNHN IM 2000-27859 (> 50), NHMW 110181 (10).

Type locality.

NeCa 12, Bouloupari: Ouaméni-valley, small stream on W-side of road in secondary forest, 21°49'46.9"S, 165°56'42.9"E, 22 May 2012.

Etymology.

The new species is dedicated to the senior author’s daughter on the occasion of her ‘quinceañera’, the 15th birthday.

Diagnosis.

Hemistomia andreae sp. n. is very similar to Hemistomia cockerelli and Hemistomia nyo . It differs from both in a clearer separation of the opercular pegs and a much more delicate penis. The protoconch of the new species has more whorls than Hemistomia nyo and the palatal denticle is further behind the outer lip.

Shell.

Conical, 2.2 times higher than wide, 4.5-5.5 whorls, without colour, transparent; protoconch faintly pitted with 1-1.25 whorls; palatal denticle large, elongate, c. 1/3 whorl behind outer lip; with columellar fold in the body whorl; aperture slightly higher than wide (Figs 2A, 3A,B, 4A,B).

Operculum.

Elongate-ellipsoidal, paucisprial, nucleus submarginal, orange, one large and one small non-calcareous white peg, well separated from each other (N=5) (Fig. 5A,B).

External features.

Epidermis without pigment, eyes black.

Mantle cavity.

Ctenidium with 24-26 (2 males) or 25-28 (3 females) filaments; osphradium kidney-shaped, behind middle of ctenidium.

Digestive system.

Radula formula (N=3) (Fig. 6A): R (rhachis or central tooth): 3 1 3/2 2, L (lateral tooth): 3 1 5, M1 (inner marginal tooth): 21-25, M2 (outer marginal tooth): 27-32; stomach without caecum; rectum close to pallial oviduct in females and to prostate in males.

Female genitalia.

Ovary without lobes, proximal end c. 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 upright comprising 180°, distal loop short; bursa copulatrix pear-shaped, reaching only slightly behind albumen gland; bursal duct long, entering anterior; seminal receptacle on ventral edge of and as long as bursa (N=3) (Fig. 7A).

Male genitalia.

Proximal end of lobate testis 1-1.25 whorls below apex, comprising 0.75 whorls, covering proximal end of stomach; vesicula seminalis arising from anterior third of testis; penis fairly delicate with blunt end (N=2) (Fig. 8A,B).

Remarks.

This is Hemistomia sp. n. 1 of Zielske and Haase (2015). Both Hemistomia andreae sp. n. and Hemistomia cockerelli do have the columellar fold in the body whorl assumed to be unique in Hemistomia nyo by Haase and Bouchet (1998). Hemistomia andreae sp. n. is only known from the type locality.