Parachernes (Parachernes) nigrimanus ( Banks, 1902 )

Mahnert, Volker, 2014, Pseudoscorpions (Arachnida: Pseudoscorpiones) from the Galapagos Islands (Ecuador), Revue suisse de Zoologie 121 (2), pp. 135-210 : 188-191

Parachernes (Parachernes) nigrimanus ( Banks, 1902) Figs 67-71

Chelanops nigrimanus Banks, 1902: 80 (type locality: Albemarle = Isabela)

Parachernes (Argentochernes) nigrimanus (Banks) : Chamberlin, 1934: 12.

Parachernes nigrimanus (Banks) : Beier, 1940: 171, Muchmore, 1999: 108-109.

Parachernes (Parachernes) nigrimanus (Banks) : Harvey, 2013, unpaginated.

Parachernes d. darwiniensis Beier, 1978: 541-543 , fig. 6 (type locality: Isabela); syn. n.

SPECIMENS EXAMINED: CAS 175 000; ♀ holotype; Albemarle Island, Iguana Cove, 1899 (JC-799.01001). – Espanola: RBINS; 13; second caleta W of Bahia Gardner, night catches, 16.- 17.IV.1991, leg. L. Baert, J.-P. Maelfait & K. Desender (B.91/673). – Fernandina: TNSC 39258; 1♀; 23.IV.1979, leg. D. Werner. – Floreana: 39339; 13; Black Beach, 5 m, sweeping in Acacia, Cryptocarpus, Plumbago above beach, 17.II.1977, leg. W. G. Reeder. – RBINS; 13; Black Beach, night catches, 8.-9.IV.1991, leg L. Baert, J.-P. Maelfait & K. Desender (B.91/624). – RBINS; 13; south of Black Beach, dry arid zone, 5 m, pitfall, 8.-20.IV.1991, leg. L. Baert, J.-P. Maelfait & K. Desender (B.91/705). – 1♀; Black Beach, arid zone, beating, 20.-28.III.1989, leg. S. Peck (89-163). – 13; Cerro Pajas, 325 m, forest interior, FIT, 27.III.-18.IV.1996, leg. S. Peck (96-57). – Isabela: TNSC 39247; 13; flat between Beagle Crater and Volcan Darwin, 50 m, old burn “witer” grass, some Waltheria, dead Bursera and Cordia , night collection, no date, leg. W. G. Reeder (?). – 39245; 1♀; eastern slope of Volcan Alcedo, 340 m, Bursera stand with Macraea, Waltheria, under bark and in rotten trunk of Bursera , 19.V.1980, leg. W. G. Reeder. – 39252; 1♀; Volcan Alcedo, eastern slope, 780 m, sweeping, Scalesia branch tips only, Scalesia savanna, 13.V.1980, leg. W. G. Reeder. – 39246; 1D; Volcan Alcedo, eastern slope, 790 m, sweeping maidenhair fern stand on precipitous stream cut, moist, overhung by Pisonia, Tournefortia, 14.V.1980, leg. W. G. Reeder. – 39261; 33 1T; Volcan Alcedo, eastern slope, 790 m, screened from eight finch and two mockingbird nests in Zanthoxylum , 5-7 ft above ground, Cassia, Ipomoea, Tournefortia, 14.V.1980, leg. W. G. Reeder. – 39028; 13 1T; Volcan Alcedo, Bursera Camp , 340 m, 18.V.1980, leg. W. G. Reeder. – 39264; 1♀; eastern slope of Volcan Alcedo, 340 m, on or under exfoliating bark of Bursera, Waltheria, Macraea , 19.V.1980, leg. W. G. Reeder. – 39340; 13; Sierra Negra, road to Sierra Solitaria, 200 m, screened from epiphytic moss on Psidium galapageium and Zanthoxylum, Scalesia-Guayavilla assoc., 25.I.1975, leg. W. G. Reeder. – 39331; 1P; Sierra Negra, zona Velasco Ibarra, 780 m, screening of litter in encanada near Scalesia Quad , mostly fern, Ipomoea, Zanthoxylum, Tournefortia , 25.I.1978, leg. W. G. Reeder. – 39369; 1T; Cabo Berkeley, 40-140 m, under ash plates and lava erratics, orgo del burro, Waltheria, Tribulus, Boerhavia (?), 8.VIII.1977, leg. W. G. Reeder. – 39324; 1T; Cabo Berkeley, 20-90 m, sweeping in Waltheria, Boerhavia and Alternanthea, 8.VIII.1977, leg. W. G. Reeder; – RBINS; 1♀ 1T; Volcan Alcedo, flanc est, alt. 400 m, 2.IV.1986, leg. L. Baert, J.-P. Maelfait & K. Desender (144). – Marchena: 39366; 1♀; SW slope, Beach Camp area, 10 m, sweeping in Waltheria and Lantana, Bursera-Croton comm., 25.I.1977, leg. W. G. Reeder. – RBINS; 1♀; Punto Meijo, 0-5 m, 11.III.1988, leg. L. Baert, J.- P. Maelfait & K. Desender (411). – 1♀; Punta Espejo, arid zone, Bursera grassland, night collection, 11.III.1992, leg. S. Peck & J. Cook (92-17). – 13, SW Playa, arid zone, Bursera forest, Malaise trap, 30 m, 12.-24.III.1992, leg. S. Peck (92-28). – 1♀; SW Playa, arid zone, night collection, 23.III.1992, leg. S. Peck & J. Cook (92-69). – 1♀; Tagus Cove, arid zone, UV light and night collection, 20 m, 13.V.1992, leg. S. Peck & J. Cook (92-176). – Rabida: 39317; 1♀; north slope, 600-900 ft, from 8 old dismantled finch nests, from Bursera , Opuntia , and Maytenus, 29.IX.1979, leg. W. G. Reeder. – 39309; 1D; north slope, 600-900 ft, from 4 dis- mantled nests (3 finch, 1 mockingbird) in Maytenus-Croton, 29.IX.1975, leg. W. G. Reeder. – 1T; NE Coast, arid zone, 40 m, FIT, 2.-11.VI.1991, leg. S. Peck (91-179). – 1P; beach, 0 m, under Cryptocarpus pyriformis near sea lion colony, leaf litter, 25.XII.1986, leg. H. Schatz (87- 406). – San Cristobal: MHNG; 1♀; 2 km NE Baquerizo, littoral zone, 15.II.1989, leg. B. J. Sinclair (89-70). – 1D; 3 km E Wreck Bay, upper littoral, FIT, 2 m, 14.-19.III.1996, leg. S. Peck (96-12). – 13 1♀; 2 km N Wreck Bay, arid zone, UV light, l 7.III.1996, leg. S. Peck (96-33). – 1P; lake El Junco, Fern Sedge zone, 640 m, well decayed fern litter and soil, under Pteridium aquilinum , 1.I.1987, leg. H. Schatz (87-441). – 1P; around lake El Junco, Miconia /cultivated zone, 650 m; under Psidium guajave and Pteridium aquilinum , decayed leaf litter, 1.I.1987, leg. H. Schatz (87-G044). – 1P; in encada with small river, SE under lake El Junco, Miconia zone, 500 m, well decayed leaf litter and roots, under Miconia robinsoniana and Pteridium aquilinum , 1.I.1987, leg. H. Schatz (87-G045). – Santa Cruz: 1T 1P; Los Gemelos, 3 km N Santa Rosa, 570 m, Scalesia forest litter, 13.VI.1985, leg. S. & J. Peck (85-188a). – 23 2♀; 10 km N Santa Rosa, 500 m, transect zone forest, FIT, 7.-30.III.1992, leg. S. Peck (92-5). – 13; 10 km N Santa Rosa, 500 m, trans. zone forest Pisonia, Malaise, 1.-30.IV.1992, leg. S. Peck (92-82). – 13 2♀; 10 km N Santa Rosa, 500 m, trans. through Pisonia forest, FIT, 1-30.IV.1992, leg. S. Peck (92-83). – 13 2T 1D; 10 km N Santa Rosa, 500 m, trans. zone forest, Pisonia, FIT, 1-30.V.1992, leg. S. Peck (92-220). – 13; 13 km N Santa Rosa, 300 m, arid zone, Bursera forest, FIT, 7-30. III.1992, leg. S. Peck (92-3). – 1♀, El Granillo, 300 m, 9 km N Los Gemelos, transect forest, UV light, 15.VI.1991, leg. S. Peck (91-229). – 1♀; CDRS, arid zone, beating, 19.I.1989, leg. S. Peck (89-21). – 1♀ 1D; CDRS, arid zone, Malaise-FIT, 40 m, 1-30.V.1991, leg. S. & J. Peck (91-110). – 1♀ 1P; Tortuga Bay, 1 m, litter on sand under machineel, 30.I.1989, leg. S. Peck (89-23). – 13; 5 km N Puerto Ayora, 110 m, low transition zone, Malaise-FIT, 1-30.V.1991, leg. S. & J. Peck (91-111). – 13; Puerto Ayora, village, UV light, 11.VI.1991, leg. S. Peck (91-219). – 1♀; CDRS, Punto Ayora, arid zone, at lights, 4-7.III.1992, leg. S. Peck et al. (92-1). – MHNG; 1 3; Puerto Ayora, synanthropic, 23.III. 1997, leg. C. & B. Komposch. – 1T; north side, 1 km E Cal. Tortuga Negra, soilwashing, upperbeach, 2.IV.1989, leg. S. Peck (89-189). – MZBE; 13; Cueva Gilberto Moneayo, 16.VIII.1975, leg. O. Escola. – RBINS; 13; north slope, alt. 150 m, 2.IV.1988, leg. L. Baert, J.-P. Maelfait & K. Desender (503). – Santa Fé: 39277; 13; second barranco 1 km SSW of Camp Bay, fallen Opuntia trunk, very dry, Croton-Cordia association, 24.I.1979, leg. W. G. Reeder. – MHNG; 2♀; without locality; 17.XII.1988, leg. S. Abedrabbo. – Santiago: 39377; 13; 520 m, Guayavilla Quadrat, ca. 5 km SE Bahia Bucanera, sweeping in open Guayavilla parkland, heavy undergrowth of annual herbs, 20.IV.1975, leg. W. G. Reeder. – RBINS; 13; Scalesia Quadrat , 555 m, 29.III. 2009, leg. L. Baert, F. Hendrickx & W. Dekoninck (B09/042). – MHNG; 1♀; Playa Espumilla, 5 m, open Cordia woodland, FIT, 4.-13.IV.1992, leg. S. Peck (92-101). – 1P; Sullivan Bay, behind beach, Dry Zone, 5 m, under Pteridium aquilinum , needle litter with pieces of wood and sand, 26.XII.1986, leg. H. Schatz (87-426). – Seymour: MHNG; 1♀; 10 m, arid zone, Bursera forest, UV light, 23.I.1989, leg. S. Peck (89-5).

DESCRIPTION (3♀): Carapace brown, metazone with a dark, nearly quadrangular patch, whitish zone reaching lateral margin; tergites I/II with a median dark macula, lateral zones whitish, the following half-tergites brown, with a dark central spot within a lighter zone. Setae of carapace and tergites short, clavate, those of coxae and sternites mostly fine and acute. Carapace 1.1-1.3 times longer than broad; 2 eye spots present; 2 distinct, granular, transverse furrows present, the subbasal one slightly nearer to posterior margin than to median furrow; prozone smooth, mesozone with small round regular granula (separated by about one diameter), between them a fine microsculpture; anterior margin with 4 setae and 1 short preocular seta on each side, 10-12 (rarely 8) setae on posterior margin. Tergites I-X divided, anterior ones granular, posterior ones finely scaly, half-tergites I-III with 4-6 clavate setae, III-IX mostly with 3-5 (rarely 6 or 7) setae, plus a supplementary lateral and a medial anterior seta, last tergite with 2 thin and longer and finely dentate lateral setae and 2 median discal setae: manducatory process laterally granular, with 3 marginal (one tiny suboral one) and with 2 discal setae, pedipalpal coxa about 22-27 (including one tactile) setae, coxa I 8-14, II 10-14, III 11-16, IV 18-22 (♀ 31-40); spermatheca with two long thin tubes without apical enlargement (Figs 67, 71); genital opening of male with 4-5 internal smooth setae on each side; anterior genital operculum with about 40-45 discal setae in a semicircular double row (setae of second row longest and curved) and a few marginal setae in male, that of female with an oval sclerotized field with 28-35 setae; halfsternite III 4-6+3-4 suprastigmal setae, IV 3-4 (rarely 2)+1, V-X 5-7 (rarely 4 or 8) marginal setae and 1 lateral and 1 medial anterior seta, XI undivided, 6-8 setae (including 2 lateral tactile setae and 2 longer medial discal setae). Anal cone 2+2 setae.

Chelicera: 5 setae on hand, 2 basal ones finely dentate, fixed finger with 3-4 retrorse and 3 distal tiny teeth, movable finger with a triangular subapical lobe, galea of 3 short, smooth and cone-like, that of ♀ with 3 apical and 2 subapical rami (broken on both chelicerae in holotype), subgaleal seta either reaching past (3) or not reaching (♀) end of galea, serrula exterior with 20-24 lamellae, rallum of 3 setae, distal one dentate on anterior margin (all broken in holotype).

Pedipalps (Figs 68-69) densely and finely granular, trochanter with a broad and rounded dorsal hump, 1.5-1.9 (3) (♀ 1.6-1.9) times longer than broad, femur abruptly enlarged at its lateral base, 2.2-2.4 (rarely 2.5-2.6) (3) (♀ 2.2-2.5) times, patella 2.0-2.4 (3) (♀ 2.1-2.3) times, club 1.4-1.7 (3) (♀ 1.5-1.7) times, hand with pedicel 1.3-1.7 (3) (♀ 1.5-1.7: oblique orientation; holotype: hand in perfectly vertical position: 1.9) times, chela with pedicel 2.2-2.8 (3) (♀ 2.4-2.8; holotype 3.3) times, without pedicel 2.0-2.6 (3) (♀ 2.3-2.6; holotype 3.1) times longer than broad (variability seems to be high, but conditioned by the shape of the hand which makes it difficult to take measurements in a perfectly vertical position: lower ratios are obtained in a slightly oblique orientation), hand with pedicel 1.1-1.4 times longer than finger. Chelal fingers frequently gaping (3♀), fixed finger with 31-39 teeth (not countable for holotype) and 4-9 (antiaxial)/2-4 (paraxial) accessory teeth; movable finger with 35-43 teeth (not countable for holotype) and 4-8 (antiaxial)/2-4 (paraxial) accessory teeth; nodus ramosus of venom duct in movable finger level with or proximal to t, a thin venom duct reaching et in fixed finger; trichobothrial pattern as in Fig. 69, all trichobothria of fixed finger in basal half, except et.

One 3 from Floreana showes only three trichobothria on movable finger of both chelae (st being absent); one ♀ from Isabela has only two trichobothria on movable finger of left chela (sb, st being absent), but the normal number of four trichobothria on the right movable finger; one 3 from Isabela (same sample: 96-33, leg. S. Peck) possesses three trichobothria on left movable finger (st being absent), and ony 2 trichobothria (sb, st being absent) on right finger .

Leg I: femur 1.0-1.3 (3) (♀ 1.2-1.4) times, patella 2.0-2.4 (3) (♀ 2.0-2.4) times longer than deep and 1.5-1.9 times longer than femur, tibia 2.7-3.3 (3) (♀ 2.8- 3.5), tarsus 3.7-5.2 (3) (♀ 3.8-5.1) times longer than deep; leg IV (Fig. 70): femur+ patella 2.7-2.8 (13 3.4) (3) (♀ 2.7-3.1) times, tibia 3.5-4.1 (1 3 4.5) (3) (♀ 3.5-4.3) times, tarsus 3.7-4.7 (13 5.0) (3) (♀ 3.9-4.1) times longer than deep; tarsus with a subbasal sensory dome and a subapical tactile seta ( TS =0.67-0.77, length 0.12-0.15 mm), the latter smooth and longer than tarsal breadth; subterminal seta smooth, curved; undivided arolia shorter than smooth claws .

MEASUREMENTS inmm: Holotype: Totallength 3.16. Carapace 0.81/0.65. Pedipalps: trochanter 0.38/0.24, femur 0.64/0.30, patella 0.70/0.30, handwithpedicel 0.75/0.39, lengthofpedicel 0.10, lengthoffinger 0.57, ofchelawithpedicel 1.28. Leg I: femur 0.20/0.14, patella 0.33/0.14, tibia 0.29/0.09, tarsus 0.30/0.07; legIV: femur+patella 0.65/0.21, tibia 0.47/0.12, tarsus 0.36/0.09.

9 males (6 females) (from Barrington, Espanola, Fernandina, Floreana, Isabela, Marchena, SantaCruz, Santiago, Seymour): Totallength 1.86-2.59 (2.45-3.28). Carapace 0.71-0.81/0.59-0.66 (0.81-0.87/0.64-0.75). Pedipalps: trochanter 0.32-0.39/0.59- 0.66 (0.36-0.40/0.20-0.24), femur 0.53-0.64/0.20-0.26 (0.59-0.64/0.25-0.27), patella 0.51-0.68/0.23-0.29 (0.59-0.68/0.28-0.29), hand with pedicel 0.57-0.68/0.37-0.51 (0.62-0.74/0.41-0.48), lengthofpedicel 0.08-0.12 (0.07-0.11), offinger 0.48-0.56 (0.48-0.58), ofchelawithpedicel 0.97-1.15 (1.03-1.22). LegI: femur 0.15-0.19/0.13- 0.15 (13 0.19) (0.17-0.21/0.14-0.16), patella 0.28-0.30/0.11-0.14 (0.30-0.32/0.14- 0.15), tibia 0.25-0.28/0.05-0.07 (0.27-0.31/0.09-0.10), tarsus 0.25-0.29/0.05-0.07 (0.26-0.29/0.06-0.07); legIV: femur+patella 0.53-0.59/0.19-0.22 (13 0.16) (0.60- 0.65/0.20-0.23), tibia 0.39-0.45/0.10-0.12 (13 0.09) (0.44-0.47/0.11-0.13), tarsus 0.31-0.35/0.07-0.08 (0.32-0.36/0.07-0.09).

REMARKS: Banks (1902) indicated as type locality “...found within the hollow of a dead twig of a bush in the small, very dry valley at the head of Tagus Cove, Albemarle”. The corresponding slide label bears the indication “Iguana Cove”. Both localities are on the west coast of Isabela , Tagus Cove in the northern part opposite Isla Fernandina , near Volcano Darwin , Iguana Cove (=Caleta Iguana) lies near Volcano Cerro Azul on the southwestern coast .

An important characteristic of this species seems to be the coloration of the carapace and tergites I/II (dark median macula and whitish lateral zones), but this is not present in all specimens of a given population. Furthermore, the chelal fingers are gaping in many, but not all, specimens (3♀). The shape of the pedipalps is characteristic, but the proportions of the chela are difficult to measure consistently because of the deep hand (a slight inclination will drastically change the length/breadth ratio).

The single male from Cueva Gilberto Moncayo (Santa Cruz) shows all the main characteristics of the species, but it has more slender legs IV. More specimens from this cave should be studied to verify the consistency of this difference.

Nymphal stages of this species can easily be distinguished from those of P. galapagensis Beier, 1977 and P. franzi Beier, 1978 by the presence of a longer and smooth tactile seta on tarsus IV and by the presence of finely dentate lateral tactile setae on tergite XI, though deutonymphs of franzi sometimes possess on tergite XI longer lateral setae that are apically clavate.