Pholcus guadarfia, Dimitrov & Ribera, 2007

Dimitrov, Dimitar & Ribera, Carles, 2007, The genus Pholcus (Araneae, Pholcidae) in the Canary Islands, Zoological Journal of the Linnean Society 151 (1), pp. 59-114 : 62-67

GENUS PHOLCUS WALCKENAER, 1805 PHOLCUS GUADARFIA SP. NOV. ( FIGS 1–7 )

Holotype: m, SPAIN, Canary Islands, Lanzarote, Barranco de la Espoleta , 1.ii.2003, Dimitrov & De Mas leg. (direct collection) ( CCRUB 4578–172 ).

Paratypes: Same data as for holotype, 1 mm, 4 ff ( CCRUB 4583-172 , 4579-172 ) ; 1 m and 1juv. same data as for holotype ( ULL AÑ-2151 ) ; 2 ff ( CCRUB 4677-173 , 4678-173 ) .

Etymology: The species name honours Guadarfia, last king of the native inhabitants (guanches) of Lanzarote Island. Noun in apposition.

Diagnosis: Distinguished from similar congeners ( P. edentatus and P. fuerteventurensis ) by the larger and heavily sclerotized apical apophysis of the procursus; the presence of four small dorsal spines on the procursus, as well as by a nearly straight and sharpened apophysis of the genital bulb appendix ( Fig. 2 ). Other important characteristics are the shape of the uncus and the conspicuously curved trochanteral apophysis. Females are distinguished by the shape of the triangular plate of the epigynum and the morphology of the vulva ( Figs 4, 7 ).

Description: Male (Holotype): prosoma oval with brownish-yellow colouring. Dorsally with brownish marking divided into two parts by a yellowish fovea. Each part subdivided once more by yellow-coloured zones. Margins of the brownish pigmented area irregular. Well-marked fovea. Elevated ocular area. The two lateral triads on short cylindrical outgrowths with darker brownish colour. AME at the height of the upper margin of the ALE. Frontally, the ocular elevation darker with dark brown marking, starting close to the top of the AME and extending to the base. Diameter of AME one-third the diameter of ALE. Distance between AME and ALE half the diameter of ALE. Dorsally, the ocular elevation carries two rows of long hairs. Chelicerae brownish with dark brown distal cheliceral apophyses ( Fig. 6 ). Distal cheliceral apophyses with two modified hairs at the tip. Upper margin of the proximolateral apophyses higher than the base of frontal prominences. Legs and palp with brownish colouring slightly darker than prosoma. Palp as in Figures 1, 2 and 5 . Opisthosoma cylindrical with brownish colour. Dorsally, ten darker spots are visible, grouped into two longitudinal rows – five in each. The first two spots in each row are larger, with ellipsoid shape while the last three are smaller, rounded and closer to the central axis of the opisthosoma. Ventrally, a darker band is visible over the gonopore. Spinnerets marked by brownish colouring.

Female: prosoma as in male but with lighter colouring; dorsally, the darker markings appear smaller; ocular area less elevated and the eyes closer. Distance between AME and ALE less than half the diameter of ALE. Dark brown areas surrounding the eyes reduced in comparison with male. Chelicerae brownish without apophyses. Opisthosoma possesses a shape and pigmentation similar to male. Epigynum with relatively small triangular plate, brownish in colour. Epigynum and vulva as depicted in Figures 3, 4 and 7 .

Measurements: Male: prosoma 1.3 long, 1.7 wide. Opisthosoma 3.7 long, 1.5 wide. Total body length 5.0. Leg I, femur 10.4, patella 0.5, tibia 9.1, metatarsus 14.7, tarsus 1.6, total 36.3. Palp: femur 0.6, patella 0.2, tibia 0.7, procursus 0.7. Female: Prosoma 1.5 long, 1.6 wide. Opisthosoma 3.7 long, 1.6 wide. Total body length 5.2. Leg I, femur 8.6, patella 0.6, tibia 8.7, metatarsus 13.9, tarsus 1.7, total 33.5.

Distribution: This species is endemic to Lanzarote and is known only from the type locality ( Fig. 276 ).

Natural history: P. guadarfia was collected in an open valley with heavily eroded margins and very scarce vegetation at 20–50 m above sea-level. This spider lives in spaces between the substrate and the bottom of large stone blocks, which are scattered among the limits of the ravine. It builds small webs attached to smooth surfaces free of sand or other materials.

PHOLCUS MALPAISENSIS WUNDERLICH, 1992

( FIGS 8–24 )

Pholcus malpaisensis Wunderlich, 1992: 321 , figs 165, 166.

Neotype: By present designation, m, SPAIN, Canary Islands, Tenerife, Barranco de Badajoz , 12.viii.2003, Dimitrov & Txasko ( CCRUB 4535-171 ).

Other material: Same data as for neotype, 3 mm, 3 ff ( CCRUB 4638-173 , 4621-173 , 4530-170 ) ; Tenerife , Barranco de Las Raíces, 2 mm, 1 f, 12.viii.2003, Dimitrov & Txasko ( CCRUB 4529–170 ) ; 1 f, 1 m, 12.viii.2003, Dimitrov & Txasko ( ULL AÑ-2159 ) ; Barranco de Las Raíces , 1 juv., 1f, 3.iii.2002, Dimitrov, De Mas & Ribera ( CCRUB 4534–170 ) .

Diagnosis: Distinguished from its similar relatives ( P. roquensis and P. knoeseli ) by the shape of the uncus, which in P. malpaisensis is both much thicker over its last third and more curved. The shape of the male bulb’s appendix is also different across the three species and a very useful tool for proper identification ( Figs 9 , 20 ). The apical apophysis of the procursus does not have the long curved outgrowth observed in P. roquensis , and has longer spines than P. knoeseli . Other important characteristics are the morphology of the procursus ( Figs 8, 9, 12 , 21, 22, 24 ) and the shape of the cheliceral apophyses ( Figs 13 , 16, 18 ). Distinctive female characteristics include the more regular colouring of the triangular plate of the epigynum (in P. knoeseli and P. roquensis two of the apexes have darker zones, with the rest much lighter in colour), and the shape of the valve ( Fig. 11 ).

Description: Male (Neotype): Oval prosoma with brownish-yellow colouring. Dorsally, a brownish marking, with smooth borders over the thorax. The marking divided into two parts by the fovea, which is well marked. Elevated ocular area with dark brown pigmentation surrounding the eyes. Dorsally, the ocular area carries a group of long hairs. Frontally, the ocular elevation with darker pigmentation. Diameter of AME half the diameter of ALE. Distance between AME equal to their diameter; distance between them and ALE equal to ALE diameter. Yellowish sternum with brownish margins, and a light-brownish marking covering its last two-thirds. Chelicerae brownish with dark brown distal cheliceral apophyses ( Fig. 18 ), the latter with two modified hairs at the tip. Near the base of the distal cheliceral apophyses groups of modified hairs (bristles) are visible. Apex of proximolateral apophyses does not extend to the base of frontal prominences. Chelicerae as in Figures 13 , 15 and 16 . Palp as in Figs 8, 9 and 12 . Procursus has two small dorsal spines ( Figs 9 , 19 ), one smaller and placed dorsoretrolaterally. Procursus’ apical apophysis as in Figure 22 , its terminal apophysis well developed with small conical elevation ( Fig. 21 ). Tarsal organ as in Figure 23 . Opisthosoma cylindrical with yellow–grey colouring. Dorsally, two longitudinal lines of darker spots are visible, each line with four spots. The first three spots are tear-shaped, the last smaller and rounded. Ventrally, genital zone slightly elevated and darker in colour. Gonopore as in Figure 17 . Spinnerets with brownish markings.

Female: Prosoma as in male but with smaller darker markings over the thorax. Ocular area less elevated with eyes closer together. Distance between AME and ALE half the diameter of ALE. Sternum with smaller marking and lighter colouring. Chelicerae without apophyses. Opisthosoma as in male but lighter in tone. Epigynum and vulva as in Figures 10, 11 and 14 .

Measurements: Male: Prosoma 1.7 long, 1.8 wide. Opisthosoma 4.8 long, 2.2 wide. Total body length 6.5. Leg I, femur 12.7, patella 0.7, tibia 13.7, metatarsus 22.0, tarsus 1.6, total 50.7. Palp: femur 1.0, patella 0.3, tibia 1.1, procursus 1.4. Female: Prosoma 1.5 long, 1.9 wide. Opisthosoma 5.3 long, 2.4 wide. Total body length 6.8. Leg I femur 12.7, patella 0.8, tibia 14.1, metatarsus 24.9, tarsus 2.9, total 55.4.

Distribution: This species is native to Tenerife where it is found in the Guimar zone, in concrete in Barranco de Badajoz and Malpais de Guimar ( Fig. 276 ). This species has also been collected in the Los Raices area. Although P. malpaisensis was collected by Wunderlich (1992) in Malpais de Guimar, we were unable to locate it. Nevertheless, Malpais of Guimar should be included as part of its distribution.

Discussion: The first description of this species was based solely on female specimens from Malpais de Guimar in south-east Tenerife ( Wunderlich, 1992). Together with the rest of the specimens, they were deposited in the ULL. Unfortunately, no other specimens were subsequently collected, and both type material and paratypes formerly deposited at the ULL have been lost. Moreover, the information and very few illustrations provided in the original description are applicable to at least two other species native to Tenerife – P. knoeseli and P. mascaensis . This could easily lead to considerable taxonomic confusion, as an objective identification of P. malpaisensis remains virtually impossible. To resolve this taxonomic confusion, and in accordance with Article 75 of the ICZN (4th edition), a neotype was designated. As there are no known specimens of this species, a neotype was chosen from material collected by us from a locality just 3 km distant from the original type locality. This neotype is based on a male specimen and has been deposited in the CCRUB.

Although several trips were undertaken to Malpais de Guimar to collect material from the original type locality, none was found. Numerous factors may explain its absence, given the considerable changes this region has undergone during the last decade. For example, all agricultural activities have been banned and the area is now a protected natural reserve.

Taking into account the dubious taxonomic classification of P. malpaisensis , the discovery of an apparently new Pholcus so close to the type locality presented two options regarding its own taxonomical placement: (1) we could claim it as a new species and risk creating an unnecessary synonymy; or (2) we could classify it as P. malpaisensis based on its proximity to the type locality and the absence of any discrepancies from the original diagnosis. As explained above, we opted to designate a neotype to better clarify a muddled situation.

P. malpaisensis shares similar morphologies with the rest of the endemic Tenerifean Pholcus species , the most remarkable characteristics being the shape of the apical apophyses of the procursus and the shape of the uncus.

Natural history: Typical locality where we could find P. malpaisensis was located at about 1 km after the entrance of the Barranco de Badajoz. This part of the gorge is narrow with very high and almost vertical walls. The whole area is very humid and has abundant vegetation in places with enough sunlight. There are several artificial galleries which were built to collect water for a small pumping station. All specimens were collected in entrances of galleries and around the pumping station. Most of the spiders were collected from ceilings but also some were found on different levels on the walls and even close to the ground. In all cases if the web was not directly on the ceiling it was built under protruding parts or small cavities on the walls, or under fallen rocks and cement blocks.

Figures

Figure 276. Known distribution of Pholcus species endemic to the Canary archipelago.

Figures 1–7. Pholcus guadarfia sp. nov.: 1, male palp, prolateral; 2, male palp, retrolateral; 3, epigynum, lateral; 4, vulva, dorsal; 5, male palp, frontal; 6, male chelicerae, frontal; 7, epigynum, ventral. Scale bars 0.2 mm.

Figures 8–14. Pholcus malpaisensis: 8, male palp, prolateral; 9, male palp, retrolateral; 10, epigynum, lateral; 11, vulva, dorsal; 12, male palp, frontal; 13, male chelicerae, frontal; 14, epigynum, ventral. Scale bars 0.2 mm.

Figures 15–24. Pholcus malpaisensis: 15, male chelicerae, frontal; 16, male chelicerae, lateral; 17, male gonopore, ventral; 18, tips of the distal apophysis of male chelicerae, retrolateral; 19, small dorsal tooth of the procursus, dorsal (arrow points to the tooth); 20, projections of the male bulb, retrolateral; 21, apex of the procursus, retrolateral; 22, apex of the procursus, ventral; 23, male tarsal organ, 24, procursus, dorso-retrolateral. Scale bars: 15, 16, 20, 21, 22, 24, 200 µm; 23, 29, 50 µm; 17, 100 µm; 18, 20 µm.