Paraliochthonius litoralis, Mahnert, 2014

Mahnert, Volker, 2014, Pseudoscorpions (Arachnida: Pseudoscorpiones) from the Galapagos Islands (Ecuador), Revue suisse de Zoologie 121 (2), pp. 135-210 : 140-143

Paraliochthonius litoralis sp. n. Figs 7-13

HOLOTYPE: RBINS; 3; SantaCruz, zonedetransition, 7.II.1974, leg. S. Jacquemart (76A).

PARATYPES: Fernandina : MHNG; 1T; CaboHammond, seacliffspraying, 24.V.1996, leg. S. Peck (96-207) . – Santa Cruz: MHNG; 1♀; Volcan Alcedo, littoral, sea cliff spraying, 1.-3.IV.1996, leg. S. Peck (96-77).

ETYMOLOGY: The name is the Latin adjective litoralis = of the seashore.

FIGS 7-13

Paraliochthonius litoralis sp. n., 3 holotype (unless indicated otherwise). (7) Epistome of carapace. (8) Leftchelicera. (9) Leftpedipalp. (10) Pedipalpalchela, lateralview. (11) Trichobothrial pattern of tritonymph. (12) Left coxae I/II. (13) Genital region. Scale unit 0.1 mm.

DIAGNOSIS: Carapace with 4 eyes, epistome slender, triangular; pedipalps: femur 5.1 (3)/4.6(♀) timeslongerthanbroadand 2.0-2.1 (♀) longerthanpatella, patella 2.1 (3)/2.0 (♀) timeslongerthanbroad, hand 2.0 (3)/ 1.7 (♀) timeslonger thandeep, fixedfinger 1.84 (3)/1.99 (♀) timeslongerthanhand, chela 5.6 (3)/5.0 (♀) times longer than deep; dorsum of hand with 8-9 chemosensory setae between ib/isb and esb, paraxial margin of hand with 2 spine-like setae in distal half, one thickened seta at base (paraxial side) of movable finger; fixed finger homodentate, with 29-30 acute, upright, distinctly separate teeth, movable finger with 31-32 acute, upright, separate teeth (a few slightly retrorse teeth near fingertip).

DESCRIPTION: Colour yellowish brown. Carapace indistinctly longer than broad, basally narrowed, posterior margin concave, epistome (Fig. 7) slender and triangular, four corneate eyes present, posterior ones with flattened lens, chaetotaxy: 4 (plus one subocular seta on each side)-4-4-2-2, length of anterior medial seta 0.09 mm; tergal chaetotaxy: I-III 4, IV-V 6, VII-IX (6)-7, X 4, XI 4 (2 tactile setae); manducatory process 2, pedipalpal coxa itself 3 setae (one discal one), coxa I 3, II 3+4-5 coxal spines (Fig. 12), III/IV 5, intercoxal tubercle absent; genital operculum 10 setae (4 discal ones), male genital opening slit-like (Fig. 13), 7 marginal/submarginal setae on each side, 4+4 internal glandular setae; sternites III/IV 6 setae, 3-4 suprastigmal setae on each side, V-XI 10/10/9-10/9-11/9-11/9-10-9 (4 tactile setae). Pleural membrane papillostriate.

Chelicera (Fig. 8): 5 setae on hand, one long seta in middle of movable finger, fixed finger with 6-7 acute and separate teeth (distal one larger), movable finger with about 6-7 acute separate teeth, spinneret absent or very indistinct, serrula exterior with 19-20, serrula interior with 14 lamellae, rallum with 7(?)-8 dentate setae.

Pedipalps (Figs 9-10): trochanter 1.8 (3)/1.9 (♀) times longer than broad, femur 5.1 (3)/4.6 (♀) times longer than broad, patella 2.1 (3)/2.0 (♀) times longer than broad, hand 2.0 (♀)/1.7 (♀) times longer than deep, fixed finger 1.84 (3)/1.99 (♀) times longer than hand, chela 5.6 (3)/5.0 (♀) times longer than deep; chaetotaxy of femur 4-5/5/2/5, slit sensillum between 3 rd and 4 th seta of anterior row, dorsum of hand with 8-9 chemosensory between ib/isb and esb, paraxial margin of hand with 2 spine-like setae in distal half, one thickened seta at base (paraxial side) of movable finger; fixed finger homodentate, with 29-30 acute, upright, distinctly separate teeth, movable finger with 31-32 acute, upright, separate teeth (near finger claw a few slightly retrorse teeth), four slightly lanceolate setae near st/t, no modified apodeme at base of movable finger.

Leg I: femur 5.0 (3)/4.4 (♀) times longer than deep, patella 2.7 (3) /2.5 (♀) times longer than deep, tibia 3.6 (3)/3.3 (♀) times, tarsus 7.4 (3)/6.8 (♀) times longer than deep, tarsus 1.85 (3)/1.72 (♀) times longer than tibia; leg IV: femur+patella 2.9 (3)/2.6 (♀) times longer than deep, tibia 4.8 (3)/4.4 (♀) times, basitarsus 2.4 (3)/2.3 (♀) times, telotarsus 8.7 (3)/8.2 (♀) times longer than deep; tactile setae on basitarsus (TS=0.25) and telotarsus (TS=0.32), claws slender, longer than arolia.

MEASUREMENTS of 3 (♀ in brackets): Total length 1.38 (1.52). Carapace 0.43/0.42 (0.46/0.44). Pedipalps: trochanter 0.23/0.13 (0.21/0.11), femur 0.60/0.12 (0.54/0.12), patella 0.30/0.14 (0.26/0.13), hand 0.32/0.16 (0.27/0.16), length of fixed finger 0.59 (0.53), of movable finger 0.57 (0.51), length of chela 0.90 (0.79). Leg I: femur 0.33/0.07 (0.29/0.07), patella 0.16/0.06 (0.15/0.06), tibia 0.17/0.05 (0.16/0.05), tarsus 0.32/0.04 (0.27/0.04). Leg IV: femur+patella 0.54/0.18 (0.50/0.19), tibia 0.37/0.08 (0.34/0.08), basitarsus 0.15/0.06 (0.14/0.06), telotarsus 0.37/0.04 (0.32/0.04).

REMARKS: This new species resembles P. johnstoni ( Chamberlin, 1923) , known from Mexico, in having two spine-like setae on the distal part of the hand and similar measurements. It differs in having a different dentition on the movable chelal finger (teeth less separate and partly slightly retrorse), a more slender pedipalpal femur and by the position of trichobothrium sb, nearly halfway between b and st. Differences from the other species described here are given in the identification key. Paraliochthonius vachoni Harvey, 2009 (from New Caledonia) shows a similar size (length of chela 0.91 mm), but differs from the new species mainly in the chaetotaxy of the carapace (2 preocular setae on each side of carapace), in the mainly low retrorse teeth on the movable chelal finger and in the stouter chela (5.0 vs. 5.6 times) (female unknown).

The new species has been collected together with P. galapagensis sp. n. and P. rupicola sp. n. on Fernandina, and together with P. pecki sp. n. on the island of Santa Cruz. The presence of three syntopic species (96-207, leg. S. Peck) on the sea cliffs of Fernandina is surprising, even if the presence of P. litoralis is witnessed by one tritonymph only.