Paraliochthonius rupicola, Mahnert, 2014

Mahnert, Volker, 2014, Pseudoscorpions (Arachnida: Pseudoscorpiones) from the Galapagos Islands (Ecuador), Revue suisse de Zoologie 121 (2), pp. 135-210 : 145-148

Paraliochthonius rupicola sp. n. Figs 18-24

HOLOTYPE: MHNG; 3; Fernandina: CaboHammond, seacliffspraying, 24.V.1996, leg. S. Peck (96-207).

PARATYPES: IslaDarwin : MHNG; 13; aridzone, seacliffspraying, 13.V.1996, leg. S. Peck (96-178) . – Fernandina : MHNG; 13 3♀; CaboHammond, seacliffspraying, 24.V.1996, leg. S. Peck (96-207) . – SantaFé : MHNG; 23 1♀; seacliffspraying, 5.IV.1989, leg. S. Peck (89-182).

ETYMOLOGY: The name is a noun in apposition and refers to the habitat colonized by this species (lat. rupes = rock, verb colere = to live in, to inhabit).

DIAGNOSIS: Carapace with 4 corneate eyes, epistome long and slender; pedipalps: femur 5.0-5.2 times (♀ 4.7-5.0 times) (chaetotaxy: 5-5-2-5), patella 2.1-2.2 FIGS 18-24

Paraliochthonius rupicola sp. n., 3 holotype (unless indicated otherwise). (18) Carapace, epistome enlarged. (19) Left chelicera. (20) Left pedipalp. (21) Pedipalpal chela, lateral view, with details of teeth. (22) Coxae I/II, coxal spines enlarged. (23) 3 genital organ. (24) ♀ genital organ. Scale units 0.1 mm.

times (♀ 2.1 times) longer than broad, hand 1.8 times longer than deep, fixed finger 1.8-1.9 times longer than hand, chela 5.0-5.2 times longer than deep; hand with 2 long spine-like setae in medio-distal third, one slightly thickened seta in medio-basal third, movable finger with a slightly thickened seta on paraxial side near base; hand with 7-8 chemosensory setae on dorsum; fixed finger of chela with 31-35 acute erect teeth (in distal finger half with indistinctly saw-like arrangement), movable finger with 31-38 retrorse, flattened teeth.

DESCRIPTION: Colour generally light brown (carapace, pedipalps), abdominal sclerites and legs yellowish. Carapace (Fig. 18) 1.1 times longer than broad, area laterally near eyes granular, basally narrowed, posterior margin concave, with a reticulate subbasal transverse furrow; 4 corneate eyes, the posterior one flattened, epistome long and slender (partly with tiny teeth at its base), with 16 long setae (4+1 subocular seta on each side-4-4-2-2). Tergal chaetotaxy: I-III 4, IV-XI 5-7/6/6-7/6-7/7- 8/7/4/4 (2 lateral tactile setae). 2 lateral setae on acute manducatory process, pedipalpal coxa itself 3 setae (1 discal), coxa I (Fig. 22) with finger-like lateral corner, 3 setae, II 3+3-5 deeply and on entire length incised coxal spines, III-IV 5, intercoxal tubercle absent; sternite II (anterior genital operculum) with 10 (11) setae (4 median discal ones), male genital opening slit-like, with 4+4 internal setae, 8-9 marginal setae, male and female genitalia as in Figs. 23-24; sternite III 8+2x3 suprastigmal setae, IV 6+2x3 suprastigmal setae, V-IX 9-10, X 8 (2 submedial tactile setae).

Chelicera (Fig. 19): 5 setae on hand, one long seta in middle of movable finger, fixed finger with 5-7 mostly acute teeth (distal one largest) (partly worn in some specimens), movable finger with about 5-7 rounded/flattened teeth, spinneret absent, serrula exterior with 20, serrula interior with about 14 lamellae, rallum with 7 dentate setae.

Pedipalps (Figs 20-21): trochanter 1.7-1.9 times, femur 5.0-5.2 times (♀ 4.7-5.0 times) (chaetotaxy: 5-5-2-5), slit sensillum as in other species, patella 2.1-2.2 times (♀ 2.1 times) longer than broad, hand 1.8 times longer than deep, fixed finger 1.8-1.9 times longer than hand, chela 5.0-5.2 times longer than deep; hand with 2 long spinelike setae in medio-distal third, one slightly thickened seta in medio-basal third, movable finger with a slightly thickened seta on paraxial side near base; hand with 7-8 chemosensory setae on dorsum; fixed finger with 31-35 acute erect teeth (in distal half with an indistinctly saw-like arrangement), movable finger with 31-38 retrorse, flattened teeth, the basal ones small and acute, basal apodeme of movable finger unmodified; about 4 lanceolate setae near trichobothrium t. Trichobothrium ist distinctly distal to eb / esb, sb on movable finger distinctly nearer to st than to b.

Leg I: femur 4.95-5.1 (♀ 4.7-5.0) longer than deep, patella 2.7-2.8 (♀ 2.7-3.0) longer than deep, tibia 3.3-3.6 (♀ 3.6-3.8) times, tarsus 7.7-8.2 (♀ 7.7-10.0) times longer than deep; leg IV: femur+patella 2.7-2.8 (♀ 2.5-2.75) times longer than deep, tibia 4.6-4.8 times (3♀), basitarsus 2.3-2.4 (♀ 2.4-2.7) times, telotarsus 9.7-10.4 (♀ 9.5-10.3) times longer than deep. Tactile setae on basitarsus (TS=0.0.22-0.24) and telotarsus (TS= 0.30-0.35).

MEASUREMENTS of 53 (4♀ in parentheses): Total length 1.57-1.72 (1.67-2.26).

Carapace 0.54-0.56/0.50-0.53 (0.56-0.65/0.53-0.60). Pedipalps: trochanter 0.28- 0.29/0.15-0.18 (0.28-0.32/0.15-0.17), femur 0.69-0.76/0.13-0.15 (0.70-0.80/0.15- 0.16), patella 0.33-0.38/0.16-0.17 (0.35-0.39/0.17-0.19), hand 0.35-0.40/0.20-0.22 (0.39-0.42/0.21-0.24), length of fixed finger 0.67-0.71 (0.72-0.78), of movable finger 0.63-0.66 (0.68-0.72), chela length 1.02-l.12 (1.08-1.20). Leg I: femur 0.37-0.42/0.08 (0.41-0.44/0.08-0.09), patella 0.18-0.20/0.06-0.07 (0.19-0.22/0.07-0.08), tibia 0.18- 0.23/0.06 (0.21-0.24/0.06), tarsus 0.35-0.40/0.04-0.05 (0.39-0.46/0.05); leg IV: femur+patella 0.61-0.68/0.22-0.24 (0.61-0.72/0.24-0.26), tibia 0.43-0.46/0.09-0.10 (0.45-0.50/0.10-0.11), basitarsus 0.17-0.19/0.07-0.08 (0.18-0.22/0.08), telotarsus 0.42- 0.45/0.04-0.05 (0.44-0.50/0.05).

REMARKS: Paraliochthonius rupicola sp. n. shares with P. mexicanus Muchmore, 1972 the presence of three spine-like or thickened setae on the paraxial side of the hand (the basal one is distinctly weaker than the two distal ones), the presence of a slender spine-like seta at the base of the movable finger, and similar dimensions of the pedipalps, but it differs mainly by the form of the teeth on the movable chelal finger (erect in mexicanus , retrorse in rupicola ) and the position of trichobothrium sb, which is distinctly nearer to st in rupicola sp. n. (about 2.4 times closer to st than to than to sb, vs. about 1.8 times). Comparing with species with only two spine-like setae (placed on a tubercle) on the chelal hand, the new species would belong to couplet 11 ( P. hoestlandti from Madeira) ( Harvey 2009). P. hoestlandti is slightly bigger (e.g. length of finger 3 0.72-0.82, ♀ 0.84 mm vs. 3 0.63-0.66, ♀ 0.68- 0.72 mm), its coxal spines are dentate in the distal half ( Vachon, 1960: fig. 4) vs. dentate all over the length.

The species of the genus Paraliochthonius apparently invaded the Galapagos archipelago at least twice, one group of species ( P. galapagensis sp. n., P. pecki sp. n. and perhaps P. rupicola sp. n.) might be related to Atlantic species (near hoestlandti ), a second group ( litoralis sp. n.) might be related to species inhabiting the Pacific coast of Central America ( Mexico).

The genus includes 24 species from Europe (2), the Macaronesian Islands (8), Africa (1), the Caribbean region and Mexico (6), the Galapagos archipelago (4, described here) and Australasia (3) ( Harvey, 2009). The epigean species (17) occur at or near the seashore and are evidently halophile; the seven remaining species are troglobitic and restricted to caves of mainland Spain and the Macaronesian Islands (Madeira, Portugal; Canary Islands, Spain) ( Harvey, 2009; Mahnert, 2011).