Diplommatina radiiformis Preston, 1913

Heryanto, Mujiono, Nova, Laitupa, Ibnu Wahab & Nurinsiyah, Ayu Savitri, 2023, Two species of Diplommatina and a new species of Palaina (Gastropoda: Cyclophoroidea: Diplommatinidae) from Moti Island, North Moluccas, Indonesia, Raffles Bulletin of Zoology 71, pp. 331-336 : 333-335

Diplommatina radiiformis Preston, 1913

( Figs. 1 , 2b ; Table 1)

Diplommatina radiiformis Preston, 1913 : Island of Beilan-beilan

(Belangbelang); Greķe, 2017: 183, Plate 25: fig. 15-24. Diplommatina sp. 2 — Heryanto, 2011: 123.

Material examined. Specimen MZB.Gst. 22497/2, Indonesia, North Moluccas, Moti Island, Tadenas Village, forest near nutmeg plantation, 480 m a.s.l., 0°27′42.7″N 127°25′40.8″E, coll. Heryanto, May 2010 .

Diagnosis. Diplommatina radiiformis is characterised by a closely ribbed and spiral striae in between ribs, small dextral shell with a convex body whorl with two spiral palatal folds inside the body whorl and distinct columellar lamella. The species from Moti I. has similar morphological characters with D. radiiformis described and figured by Greķe (2017), especially with the distinct and dense spiral striae and the longitudinal palatals on the ultimate whorl. The specimen from Moti I. differs by having a slightly larger shell.

Description. Shell dextral; spindle shaped with a conical top and narrowed body whorl; with 7.5 whorls separated by deep suture; protoconch smooth; teleoconch with oblique ribs (penultimate and body whorl almost have same number of ribs); with spiral striae between ribs; whitish or corneous; subtranslucent; body whorl ventrally with constriction; aperture almost rounded, with a slight bend on upper insertion of peristome; insertions of peristome connected by strong callus; peristome expanded, thickened, doubled; aperture with distinct columellar lamella; ventrally inside body whorl with two spiral palatal folds close to suture; umbilicus closed. Shell height 2.7 mm, shell diameter 1.2 mm.

Habitat. The specimen was found in secondary forest, in a nutmeg plantation, on a large boulder of volcanic rock covered with herbaceous layers and moss, and in between leaf litter. On Moti I., the species was recorded at an elevation between 400 to 500 m a.s.l. However, on the other islands, the species can occur in both lower elevations (230 m a.s.l.) and higher elevations (530 m a.s.l.) ( Greķe, 2017).

Distribution. Diplommatina radiiformis is endemic to the Moluccas Archipelago ( Maluku Islands), distributed from Belang-belang I. (Obi Islands), Tidore I., and Halmahera I. ( Greķe, 2017). The distribution in Moti I. is a new record.

Figures

Fig. 1. Map of Moti I. in the North Moluccas Archipelago, with the insertion of the North Moluccas in Indonesia and the studied area in Moti I.

Fig. 2. Shells of Diplommatinidae described from Moti I. a, Diplommatina moluccensis Greķe, 2017, (MZB.Gst. 22496). b, Diplommatina radiiformis Preston, 1913, (MZB 22497). c, Palaina motiensis, new species (Holotype, MZB 22493). Scale bars = 1.0 mm.