Canariella jandiaensis Ibáñez & Ponte­Lira, 2006

Alonso, María R., Ponte-Lira, Carmen E., Castillo, Carolina, Yanes, Yurena, Groh, Klaus & Ibáñez, Miguel, 2006, A new Canariella species (Gastropoda: Helicoidea: Hygromiidae) of the new subgenus Majorata, both endemic to the Jandía Peninsula (Fuerteventura, Canary Islands), Zootaxa 1316, pp. 45-56 : 49-53

Canariella jandiaensis Ibáñez & Ponte­Lira new species

Type locality. Morro del Cavadero (Fuerteventura; U.T.M.: 28RES 6207, 720 m altitude). Holotype ( Fig. 4 B): TFMC (MT 0388); leg. K. Groh, M. Ibáñez and C.E. Ponte­Lira, 8­03­1990.

Paratypes. 430 paratypes (mainly shells), collected between 1989 and 2006: CGH (16 ethanol specimens and 44 shells), CGS (4 ethanol specimens and 4 shells), CHB (92 shells), CKW (10 ethanol specimens and 64 shells) CRJ (20 shells) MNHN (1 shell), NHM (1993053/1 shell), NMB (753.30/1 shell), NMW (Z.1992.089.03/1 shell), SMF (309933/1 shell), SMNS (3 shells), TFMC (MT 0283/1 shell), ZMZ (573823/1 shell) and AIT (12 ethanol specimens and 157 shells).

Etymology. The name jandiaensis refers to the locality, the Jandía mountains.

Distribution and habitat ( Fig. 1 ): The species is endemic to the Jandía Peninsula (southern Fuerteventura), restricted to the highest ground, living mainly on the crests and on the nearly inaccessible cliff­tops of the northern slopes at an altitude of 550– 807 m. C. jandiaensis is mostly active at night or in wet weather, remaining for the rest of the time in cracks and under rocks. It has been found in an area smaller than 1 km 2, distributed in three 1 km UTM square points. In this area the vegetation mainly consists of some plants of a thermophilous forest, considered as the ancient type by botanists, and also substitution bushes.

Diagnosis: A medium­sized Canariella with slightly depressed globular, umbilicate shell, without hairs. Penis with a proximal, large penial papilla arising from all the five epiphallar folds, overlapping distally a pseudopapilla.

Description: Body ( Fig. 4 C) normally clear brown with dark brown spots which merge in the back forming longitudinal lines; some specimens have a uniform brown body.

Shell ( Fig. 4 B) dextral, conic­ovate, dorsally low conical and ventrally ovate, with a small to medium­sized diameter and 4½–5 convex, roundish whorls with deep sutures; umbilicus medium­sized and deep, slightly obscured by the reflected lip. Aperture oblique, ovate to rounded; peristome whitish, discontinuous, a little expanded as a lip more developed in the lower part of the palatal edge and reflected in the columellar edge, covering partially the umbilicus. Peristome edges inserted next mutually in the parietal zone.

Shell colour yellowish brown, slightly glossy, with thin radial, whitish streaks in the last two whorls, more visible near the aperture. The shell also has up to three dark spiral bands, two dorsal and one less clear, ventral; these spiral bands are not exhibited in some specimens. Ornamentation characterized by sinuous, numerous radial ribs irregularly undulating, very weak on the protoconch and first whorls and well marked in the other whorls; ventral ribs smoother than dorsal ones.

Pallial region extended over last three quarters of the body whorl. Jaw odontognathous, with 6–9 very weak ribs. Radula (formula 24 + C + 24) with last teeth having a small endocone and the ectocone with two cusps.

Genital system ( Fig. 5 A; eight specimens dissected): Distal male duct (between atrium and retractor muscle insertion) shorter than proximal part of epiphallus (between retractor muscle insertion and flagellum) and almost twice as long as flagellum. These three regions are tubular and taper gradually from the atrium to the flagellum top.

Epiphallus with five thin, waved longitudinal folds which extend into the penial cavity, their distal ends merging, giving rise to a large, grooved, spoon­like penial papilla ( Fig. 5 A—c,d) of about 1/3 of penis length.

Moreover, the penis exhibits a grooved pseudopapilla ( Fig. 5 A—c,d), also spoon­like, partially covered proximally by the penial papilla. When penis evaginates, the pseudopapilla appears forming a pair of oblique folds behind the papilla ( Fig. 5 A—f), probably for anchorage in the partner's genital system during the coitus. The proximal inner penis wall is smooth (except in the pseudopapilla insertion), while the distal one has five longitudinal, small and thin folds.

Vagina ( Fig. 5 A—a,b,e) with three digitiform vaginal glands which open near the oviduct orifice. The vaginal glands are short and broad, each one with a slender independent initial portion. Inner vaginal wall with a variable number of irregular longitudinal folds, which are isolated from those of the beginning of the bursa copulatrix duct; in this last area the folds are irregular and anastomosed.

Remarks. C. eutropis and C. jandiaensis are the only Canariella species without hairs on the shell, even in the umbilicus. Both species are also the only Canariella species with the penial papilla arising from all five epiphallar folds; in the two subgenera with a penial papilla, Canariella and Salvinia , this papilla derives from only two of the epiphallar folds. Thus, both species represent a distinct supraspecific taxon, which will be described in this study as a new subgenus.

C. jandiaensis is easily distinguished from C. eutropis by the unkeeled, almost globular shell ( Figs. 3 , 4 B–E), which is smaller but taller than that of C. eutropis and has more numerous yet smoother radial ribs. Also, the C. eutropis penial cavity has a thick longitudinal pilaster instead of the pseudopapilla present in C. jandiaensis ( Fig. 5 ).

C. eutropis and C. jandiaensis appear to be sympatric species, with the latter occupying a subset of the former’s range. C. eutropis is not as much specialised in the habitat as C. jandiaensis , the former being able to live also in more dry habitats. The C. eutropis shell is nearly discoid and has stronger ornamentation than that of C. jandiaensis . These characteristics could represent a better adaptation of the former to get refuge with enough humidity under big stones or in rock fissures of the driest habitats.

Figures

FIGURE 1. Distribution of Canariella jandiaensis sp. nov. and C. eutropis. Symbols represent 1 x 1 km UTM squares.

FIGURE 3. Scatter plots of some shell measurements for Canariella jandiaensis sp. nov. and C. eutropis. Abbreviations same as in Fig. 2.

FIGURE 4. Shells and living specimens. A. Canariella plutonia, from Vega de Río Palmas; B – C. C. jandiaensis sp. nov., from Morro del Cavadero; B. Holotype. D – E. C. eutropis from Solana del Ciervo. Scale bar applies to A, B, D.

FIGURE 5. Genital system and details. A. Canariella jandiaensis sp. nov., from Morro del Cavadero (an AIT paratype). B. C. eutropis, from Morro del Cavadero (taken from Ibáñez et al. 1995, fig. 38). a, general appearance of the whole genital system; at, atrium; ag, albumen gland; b, detail of the distal female duct; bc, bursa copulatrix; c, detail of the distal male duct; d, epiphalluspenis diagram (without scale); e, vaginal cross­section diagram; with arrangement of vaginal glands (without scale); ef, epiphallar fold; ep, epiphallus; f, detail of the evaginated penis; showing the penial papilla; fl, flagellum; o, free oviduct; p, penis; pi, pilaster; pp, penial papilla (also marked with asterisk); ps, pseudopapilla (also marked with arrow); r, retractor muscle; s, sheath; v, vagina; vd, vas deferens; vg, vaginal gland.