Napaeus bajamarensis Ibáñez and Alonso, 2009
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publication ID |
https://doi.org/ 10.1080/00222930903094621 |
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persistent identifier |
https://treatment.plazi.org/id/4014878B-457F-7937-40A6-81AEFB23FAAD |
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treatment provided by |
Felipe |
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scientific name |
Napaeus bajamarensis Ibáñez and Alonso |
| status |
sp. nov. |
Napaeus bajamarensis Ibáñez and Alonso View in CoL sp. nov.
Type material
Holotype ( Figures 2 View Figure 2 , 4B View Figure 4 , 7A View Figure 7 ): TFMC ( MT 0397 ). Type locality: Barranco de Vargas , Bajamar, Anaga massif (Tenerife; UTM coordinates: 28 RCS7058 View Materials ; 300 m altitude); Leg. Manuel J. Valido and Fátima C. Henríquez, 1 December 1989.
Paratypes: 13 specimens and 160 shells, collected between 1982 and 2009, from the northeast of Tenerife ( UTM coordinates: 28 RCS6658 View Materials , 28 View Materials RCS6757 View Materials , 28 View Materials RCS6758 View Materials , 28 View Materials RCS6958 View Materials , 28 View Materials RCS6959 View Materials , 28 View Materials RCS7058 View Materials , 28 View Materials RCS7157 View Materials , 28 View Materials RCS7259 View Materials , 28 View Materials RCS7260 View Materials , 28 View Materials RCS7460 View Materials and 28 RCS8160 View Materials ), deposited in AIT and the following collections: CGH (31 shells), CHB (24 shells), CML (2 shells), NHM (1992154/1), FMNH (158200/6), NMW (Z 1992.072.01/1) and TFMC (24 shells, in 5 lots: MT 0118 , 0119 , 0135 , 0151 and 0152) .
Etymology
The specific name derives from Bajamar, the main area of the species distribution.
Geographic range and habitat Endemic to Tenerife, occupying an area of about 20 km 2 along the north slope of the
Anaga massif (northeast of the island), associated with lowland vegetation and humid subtropical scrub, within an altitudinal range between 20 and 750 m ( Figure 1B View Figure 1 ). The highest locality includes a pine forest. This species is a ground dweller and is the only living Napaeus species found also in the Pleistocene Aeolian area of Mancha de La Laja, Bajamar (see arrow in Figure 1B View Figure 1 ), where the oldest species of this genus (>130 kyr BP) has been collected ( Castillo et al. 2006).
Diagnosis
Shell robust, ovate, pale brown to tan brown coloured, with first whorls darker than the rest. Teleoconch almost smooth. Epiphallus with epiphallar caecum. Bursa copulatrix duct exceptionally long, with a diverticulum.
Description
Shell ( Figure 7A View Figure 7 ) dextral, robust, obese (shell breadth (SB)/shell height (SH) index), ovate, cone-shaped above, 6¾–7½ convex whorls (almost flat), marked suture. Body whorl intermediate (body whorl height at columella level (BH)/SH index), protoconch smooth, shiny, with 1½–1¾ whorls. Aperture long, wide (aperture height (AH)/SH and aperture breadth ( AB)/SB indices, respectively), with elliptical section at palatal side, slightly angular at union of columellar and palatal edges. Upper palatal side forms angle slightly less than 90º with parietal side, aperture juts out only slightly from body whorl beginning. Whitish discontinuous peristome expanded as small lip, more developed in lower part of palatal edge, reflected in columellar edge, where it partially covers umbilical slit. Older specimens with callosity between peristome edges, nodule at union of parietal–palatal area.
Shell colour pale brown to tan brown, with first whorls darker than rest. Ornamentation almost smooth, characterized by numerous weak, radial oblique ribs, regularly placed on almost entire shell ( Figures 7A View Figure 7 , 10A View Figure 10 ). Shell has some shine despite ribs.
Jaw aulacognathous, with numerous grooves, lateral extremities almost smooth. Radula ( Figure 8 View Figure 8 ) with 110–126 teeth rows, formula: C+14–15L+16– 19M. Central tooth triangular–ovate, mesocone with rounded tip and two small basal ectocones. First lateral teeth bigger and stronger than central with rounded mesocone and sharp ectocone. Towards laterals, length and width of mesocone diminish as ectocone increases, last broader than mesocone. Marginal teeth with finger-shaped mesocone, much broader ectocone divided into four to six denticles of decreasing size with serrated appearance.
Genital system ( Figure 9A–B View Figure 9 ; five specimens dissected). Atrium very short. Penis about three times shorter than epiphallus, with two portions. Distal portion tubular, located between atrium and insertion of penial retractor muscle. Proximal portion short and swollen, with well-developed penial papilla ( Figure 9B View Figure 9 ). Epiphallus tubular, opening distally on penis, two regions defined by presence of epiphallar caecum; proximal region widened, slightly longer than slender distal region. Flagellum very short. Vas deferens opens laterally on proximal end of epiphallus. Penial appendix arises in distal penis portion near retractor muscle insertion, similar in length or slightly longer than penis and epiphallus together. Part A 1 of penial appendix clearly differentiated from globular part A 2, slightly longer than penis. Appendicular retractor muscle inserts laterally, joined to penial retractor on diaphragm walls at certain distance of proximal A 1 top; appendicular insertion delimits two A 1 portions, proximal larger than distal. Part A 3 more slender, shorter than proximal A 1 portion. Parts A 3 and A 4 clearly separated from each other, A 4 long, very thin distally, passing gradually into expanded A 5.
Free oviduct longer than vagina. Vagina firmly fixed to the body tegument by short connective fibres. Bursa copulatrix complex with a well-developed diverticulum. Bursa duct exceptionally long. Two spermatophores found in diverticulum and basal stalk of bursa copulatrix complex of one specimen.
Spermatophore rigid, long, narrow, twisted, with two parts delimited by strong, spur-like hook curved towards distal tip, moulded in internal pit of epiphallar caecum. Proximal area compressed near tip with semilunar section; proximal tip probably moulded into flagellum, with oval orifice for sperm transfer; proximal edge reflected as collar in ellipsoidal lip with notch on one side. Remainder proximal area tubular, with two well-developed, non-striated longitudinal lamellae running from proximities of the lip up to near the hook. Distal area tubular, narrowing gradually towards tip (first part to be inserted in other specimen during mating), ending in rounded point. Spermatophore similar to that of N. moquinianus (Webb and Berthelot) from Gran Canaria, photographed in Alonso et al. (1995: 311, figures 22–24).
Remarks
Shell morphology. Within the conchological group of N. baeticatus , the shell of N. bajamarensis sp. nov. ( Figure 4B View Figure 4 ) is comparable in shape and size mainly with those of N. boucheti ( Figure 4C View Figure 4 ), N. obesatus ( Figure 4D View Figure 4 ) and N. tenoensis ( Figure 4A View Figure 4 ).
The shell of N. bajamarensis is more slender than that of N. tenoensis and N. boucheti and is slightly more obese than that of N. obesatus ( Figure 6A View Figure 6 ). The first whorls of N. bajamarensis are similar but slightly more obese than those of N. obesatus and bigger than those of N. tenoensis and N. boucheti ( Figure 6C View Figure 6 ). The shell aperture of N. bajamarensis is bigger than that of N. obesatus and smaller than those of N. tenoensis and N. boucheti ( Figure 6B View Figure 6 ). The shell ornamentation is almost smooth in N. bajamarensis ( Figure 10A View Figure 10 ) and well-developed in the other species ( Figure 12 A–C View Figure 12 ).
Genital system anatomy. N. bajamarensis has an exceptionally long bursa copulatrix duct; it is clearly shorter in the other three species. N. bajamarensis and N. obesatus have a well-developed diverticulum, which is lacking in N. tenoensis and N. boucheti .
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