Metafruticicola pieperi Bank, Gittenberger & Neubert, 2013

Bitzilekis, Eleftherios, Vardinoyannis, Katerina & Mylonas, Moisis, 2023, A new species of Metafruticicola (Gastropoda, Hygromiidae) from the Aegean Archipelago and new anatomical and distributional data on some congeneric species, European Journal of Taxonomy 879 (1), pp. 1-23 : 10-12

Metafruticicola pieperi Bank, Gittenberger & Neubert, 2013

Fig. 4

Material examined

GREECE – Crete, Lasithi province • 16 shells, 4 specs in 75% alcohol, 4 dissections; Avgo Islet ; 35.6028° N, 25.5769° E; 2 Mar. 1994; M. Mylonas leg.; NHMC 50.40149 • 10 shells; same collection data as for preceding; 27 Apr. 2013; NHMC 50.40340 • 34 shells; same collection data as for preceding; 6 Jun. 2018; NHMC 50.47374 • 13 shells; same collection data as for preceding; 13 Feb. 2020; E. Bitzilekis leg.; NHMC 50.48936 .

Locus typicus

Greece, Avgo Islet, Lasithi province, Crete, Greece (40 km NE of Heraklion).

Description

SHELL. Shell description is given by Bank et al. (2013: 106).

SHELL DIMENSIONS (n = 73). H 11.82–15.35 mm (mean = 13.62 mm); D 18.45–23.9 mm (mean = 21.04 mm); W 55/8–62/s (mean = 6). All the shells had one or two prominent growth interruptions.

GENITALIA ( Fig. 4 Β–E). The reproductive system and its inner structures are presented here for the first time. Flagellum very long, three times the length of the epiphallus. Epiphallus evenly thick, but it gets a bit wider near the penis. Penial retractor is attached approximately at the middle of the epiphallus. Penis curved, thicker and distinct at its junction with epiphallus, less than half the size of the epiphallus. Inside the penis there is a triangular two-lobed papilla with rounded tips and in the back side there are some weakly formed circular grooves. One of the lobes is slightly larger than the other. Epiphallic pore starts with a V-shaped slot and opens in the slit dividing the two lobes. From the rear side the two-lobed papilla has a conical shape, revealing that the lobes are not separate. Inner penial walls have a few vertical ridges ( Fig. 4C ). Vas deferens slender. Vagina thick and around the same length as the penis. The base of the duct of the gametolytic gland is thick-walled and as broad as the penis. Inside its thickened base there are three pilaster-like thickenings and some longitudinal grooves ( Fig. 4E ). Free oviduct as broad as the duct of the gametolytic gland and twice the length of the penis. Gametolytic gland globular to oval-shaped.

Remarks

Shell measurements have a wider range than those given by Bank et al. (2013) and are closer to the actual shell diversity of the species due to the larger number of examined specimens.

At first glance, Metafruticicola pieperi seems to have a bilobed papilla which, according to the division of Schileyko & Féher (2017), could be placed alongside M. redtenbacheri and M. nicosiana soror . This outcome comes in line with Bank et al. (2013), since all these taxa belong to the subgenus Rothifruticicola . However, looking at the papilla from the back side, it becomes clear that we are rather dealing with a conical papilla with a deep longitudinal groove. Thus, it is closer to the shape of the papilla of M. coartata Fuchs & Käufel 1936 , especially from the westernmost islands of its distribution (see below and Fig. 6 ), which however belongs to a different subgenus ( Westerlundia ). Moreover, the presence of “pilaster-like” structures on the inner surface of the thickened base of the duct of the gametolytic sac in M. pieperi has been recorded by Bank et al. (2013) only in M. (M.) pellita , which also belongs to a different subgenus.

Figures

Fig. 4. Metafruticicola (Rothifruticicola) pieperi Bank, Gittenberger & Neubert, 2013, Greece, Crete, Lasithi province, Avgo Islet (NHMC 50.40149). A. Shell. B. General view of genitalia. C. Internal structure of penis and rear view of penial papilla. D. Front view of penial papilla. E. Base of the duct of the gametolytic gland. Abbreviations: see Material and methods.

Fig. 6. Metafruticicola (Westerlundia) coartata coartata Fuchs & Käufel, 1936. A, D. Greece, Cyclades, Makra Islet (NHMC 50.4056). B, I. Greece, Cyclades, Fteno Islet (NHMC 50.3726). C, G. Greece, Dodecanese, Zafora Mikri Islet (NHMC 50.9955). E, H. Greece, Cyclades, Askania Islet (NHMC 50.4077).F. Greece, Cyclades, Christiani Islet (NHMC 50.3721). A. General view of genitalia. B–F. Diversity in the shape of penial papillae and inner surface of penial walls. G–I. Diversity in the shape of penis, vagina and the base of the duct of the gametolytic gland. Abbreviations: see Material and methods.