Napaeus josei Santana, Alonso & Ibáñez, 2011

Yanes, Yurena, Santana, Jesús, Artiles, Miguel, Deniz, Francisco, Martín, Javier, Alonso, María R. & Ibáñez, Miguel, 2011, Five new Napaeus species (Gastropoda: Pulmonata: Enidae) from Gran Canaria and El Hierro (Canary Islands), Zootaxa 2901 (1), pp. 35-51 : 39-43

publication ID	https://doi.org/ 10.11646/zootaxa.2901.1.3
DOI	https://doi.org/10.5281/zenodo.5292362
persistent identifier	https://treatment.plazi.org/id/8146737D-FFE0-FFD0-FF83-8E0CA3B1E3A5
treatment provided by	Felipe
scientific name	Napaeus josei Santana, Alonso & Ibáñez
status	sp. nov.

Treatment

Napaeus josei Santana, Alonso & Ibáñez View in CoL , n. sp.

Figs. 1 View FIGURE 1 , 3 A View FIGURE 3 , 4 A–C View FIGURE 4 , 5 A, B View FIGURE 5 , 6 A, B View FIGURE 6 , 7 A–C View FIGURE 7

Type locality. Barranco del Lechugal (Gran Canaria; UTM: 28RDR 3075, 100 m altitude).

Holotype ( Fig. 3 A View FIGURE 3 ; empty shell). TFMC ( MT 0415 ). Leg. J. Santana, 26 January 2009.

Paratypes. 6 specimens and 102 shells, collected between 1998 and 2010 from the southwest of Gran Canaria , deposited in AIT (6 specimens, 5 shells) and the following collections: JSGC (68 shells); FDGC (9 shells); MAGC (20 shells) .

Etymology. The specific name is dedicated to our late friend Jose María Hernández, marine malacologist from Gran Canaria.

Distribution and habitat ( Fig. 1 View FIGURE 1 ). Endemic to Gran Canaria, occupying an area of about 100 km 2 of the southwest of the island, with lowland vegetation, within an altitudinal range between 40 and 460 m. Napaeus josei ( Fig. 4 A View FIGURE 4 ) is mainly a ground dweller, living associated with large Euphorbia species , sheltering during the day under stones or between Euphorbia roots. The majority of the specimens collected had the shell disguised by a covering of soil, which was sometimes very thick ( Figs. 4 B, C View FIGURE 4 ), altering the appearance of the shell considerably as in other disguised Napaeus species ( Yanes et al. 2010). This renders most living animals very inconspicuous in their normal resting places, presumably reducing the risk of visual detection by predators. The snails are part of the diet of the Southern Grey Shrike, Lanius meridionalis Temminck ( Aves, Passeriformes ) ( Padilla et al. 2009) and the omnivorous lizard, Gallotia atlantica (Peters & Doria) , endemic to the eastern islands ( Valido & Nogales 2003). Other species of Gallotia , which as a genus is present in all the islands of the Archipelago, probably also consume snails as part of their regular diet ( Yanes et al. 2010).

Diagnosis. Shell very obese, conic-ovate, brown-coloured, with first whorls slightly darker than rest. Teleoconch granulated. Penis short and thick, with large penial papilla. System of penial appendix parts A 1 –A 3 very short. Appendicular retractor muscle inserts laterally in proximal tip of part A 3. Epiphallus with epiphallic caecum. Bursa copulatrix duct inflated, with long diverticulum.

Description. Body pale brown-greyish, covered with brown spots, denser in cephalic area ( Fig. 4 A View FIGURE 4 ). Shell ( Fig. 3 A View FIGURE 3 ) dextral, robust, very obese (SB/SH index), conic-ovate, with sharp apex, irregularly increasing whorls (penultimate whorl and body whorl giving oval appearance), 5¾–6 convex whorls and deeply marked suture. Body whorl large (SB/SH index) occupying more than ⅔ of shell surface area (BS/SS index). Protoconch smooth, with 1¾–2 whorls. Aperture long, very wide (AH/SH and AB/SB indices), rounded at palatal side, more curved at junction of columellar and palatal edges. Angle ( Fig. 2 View FIGURE 2 ) between columella and upper palatal margin about 122º. Peristome discontinuous, expanded as a wide, whitish lip, more developed in lower part of the palatal and columellar edges, reflected on columellar edge, where it partly covers umbilical slit. Older specimens with a callosity between peristome edges and a nodule at junction of parietal and palatal margins. Aperture extending laterally beyond penultimate whorl by about 32% (ca. 1 mm). Colour brown, with first whorls slightly darker than rest.

Ornamentation of first teleoconch whorl characterised by numerous, thin, radial, oblique ribs with small, irregular protuberances. Protuberances from second teleoconch whorl to body whorl more developed, and those of penultimate whorl ( Fig. 5 A View FIGURE 5 ) broader and usually equidistantly placed, giving appearance of granular rows perpendicular to radial shell ribs. Body whorl mainly with radial ribs provided with irregular granulation on the upper side ( Fig. 5 B View FIGURE 5 ).

Genital system ( Figs. 6 A, B View FIGURE 6 ; two specimens dissected). Atrium very short. Penis short and thick, without evident division into separate portions and about a third of the length of the epiphallus. Penial papilla large, welldeveloped, occupying almost all of penial cavity. Penial retractor muscle inserts apically into proximal penis tip, next to epiphallus-penis connection. Epiphallus opening distally into penis, tubular, slender, with epiphallic caecum inserting in its proximal third. Flagellum very short, globular. Vas deferens opens sub-terminally on proximal end of epiphallus. Penial appendix long, arising obliquely in distal portion of penis near atrium, longer than penis and epiphallus together. System of penial appendix parts A 1 –A 3 very short, boundary between them scarcely visible. Parts A 3 and A 4 clearly separated from each other, A 4 long and thin, passing gradually into expanded A 5. Appendicular retractor muscle inserts laterally in proximal tip of short part A 3, joined to penial retractor just before insertion on lower lung wall.

Vagina tubiform, similar in length to free oviduct and proximal third of epiphallus, respectively. Bursa copulatrix duct inflated, with diverticulum longer than duct and branching off in proximal quarter of duct, surmounting the vesicle of the bursa copulatrix.

Comparison with other taxa. Shell morphology: The shell of N. josei n. sp. ( Fig. 3 A View FIGURE 3 ) is comparable in shape and size mainly to that of N. nanodes ( Shuttleworth, 1852) ( Fig. 3 B View FIGURE 3 ) and N. badiosus (Webb & Berthelot, 1833) ( Fig. 3 C View FIGURE 3 ), both from Tenerife. The shell of N. josei is clearly more obese than that of both species ( Figs. 3 A–C View FIGURE 3 , 7 A View FIGURE 7 ). The shell aperture of N. josei is similar to that of N. badiosus and bigger than that of N. nanodes ( Figs. 3 A, B View FIGURE 3 , 7 C View FIGURE 7 ). The shell ornamentation is clearly different in the three species, the granulation of N. josei ( Figs. 3 A View FIGURE 3 , 5 A, B View FIGURE 5 ) contrasting with the sinuous, undulating ribs surrounding large depressions in N. nanodes ( Fig. 3 B View FIGURE 3 ) and the more or less uniformly ribbed, not granulated shell of N. badiosus ( Fig. 3 C View FIGURE 3 ).

Genital anatomy: N. josei has an enormous penial papilla ( Fig. 6 B View FIGURE 6 ), the largest known in the genus, occupying almost the entire penial cavity.