Pionothele gobabeb, Bond, Jason E. & Lamb, Trip, 2019

Bond, Jason E. & Lamb, Trip, 2019, A new species of Pionothele from Gobabeb, Namibia (Araneae, Mygalomorphae, Nemesiidae), ZooKeys 851, pp. 17-25 : 17

Pionothele gobabeb sp. n. Figs 1, 2-4, 5-9

Type material.

Male holotype (NMB012_001; deposited in the BME) and additional male paratypes (one each deposited in the NMN, and CAS) from the Erongo Region, Namibia, in vicinity of Gobabeb Research & Training Center, along D1983 and Kuiseb River, - 23.56984 15.03984, coll. by J. Bond and T. Lamb 27.ix.2013.

Etymology.

The specific epithet is a noun taken in apposition and is in reference to the type locality.

Diagnosis.

Male and female specimens (Figs 2-4) can be differentiated from the other two described species of Pionothele by having posterior median eyes that are reduced in size (Fig. 7), nearly half the diameter of the posterior lateral eyes and much smaller than the anterior median eyes. Like P. capensis the male palpal tibia is more slender than in P. straminea but like the latter lacks spines (Fig. 8); leg I has more mid-retrolateral spines than P. capensis , with a single large mid-distal spine and only two proximal prolateral spines (Figs 5, 6). Males and females both are very light in coloration similar to that of P. straminea (Figs 2-4), noted by Raven (1985) as “faded,” whereas the abdomen of P. capensis is pigmented and mottled. Spermathecal bulbs of P. gobabeb are moderately thin and sinuous whereas those illustrated for P. capensis are described as "wide and flattened" (Fig. 9); females also appear to have far fewer endite cuspules (25 vs 80).

Description of male holotype.

Specimen preparation and condition. Specimen preserved in 70% EtOH. Pedipalp, leg I removed, stored in vial with specimen. General coloration in alcohol. Carapace yellowish-red 5YR 4/6. Abdomen very pale brown 10YR 7/3. Cephalothorax. Carapace 7.58 long, 6.80 wide, very hirsute with fine white setae, pars cephalica slightly elevated. Fringe lacks heavy setae at posterior corners. Foveal groove deep, procurved.Tubercle absent. AER, PER slightly procurved. PME much smaller in diameter than AME, half the size of PLE. Sternum moderately setose, STRl 4.41, STRw 3.40. Posterior sternal sigilla small, round not contiguous; anterior sigilla pair smaller, placed at margin. ANTd comprising 5 large teeth; posterior margin with single row of 6 smaller teeth. Palpal endites, ~21 cuspules restricted to the anteroproximal margin, labium lacking cuspules, LBw 0.92, LBl 0.67. Rastellum absent. Abdomen. Moderately setose; apical segment of PLS short, triangular in shape. Legs. Leg I: 8.92, 4.62, 5.81, 4.16, 3.14; leg IV: 8.924, 3.31, 7.38, 6.95, 3.93. Light scopulae on all tarsi. Tarsus I with thin band of ~20 trichobothria. ITC legs I–III absent, leg IV small, sharply curved. Paired claws biserially dentate. Leg I spination pattern (Figs 5, 6); TSp 4, TSr 4, TSrd 1. Pedipalp.PTw 0.1.18, PTl 3.77, Bl 1.86. Embolus arises sharply from bulb, long thin tapered (Fig. 8).

Variation (n = 5).

Cl 6.18-7.59, 6.96 ± 0.27; Cw 5.72-6.8, 6.24 ± 0.21; STRl 3.56-4.41, 3.99 ± 0.16; STRw 2.78-3.4, 3.1 ± 0.12; LBw 0.88-1.11, 1.01 ± 0.05; LBl 0.54-0.67, 0.62 ± 0.02; leg I: 7.66-8.92, 8.45 ± 0.24; 4.07-4.65, 4.39 ± 0.13; 5.11-5.81, 5.39 ± 0.13; 3.61-4.33, 4.03 ± 0.12; 2.9-3.4, 3.14 ± 0.09; leg IV: 7.96-8.92, 8.51 ± 0.21; 2.75-3.72, 3.27 ± 0.16; 5.98-7.38, 6.54 ± 0.26; 5.5-6.98, 6.39 ± 0.27; 3.36-3.93, 3.78 ± 0.11; PTl 3.45-3.88, 3.72 ± 0.08; PTw 0.88-1.18, 1.01 ± 0.06; Bl 1.86-2.19, 2.02 ± 0.07; TSp 2-4, 3.4 ± 0.4; TSr 2-4, 3 ± 0.32; TSrd 1-1, 1 ± 0.

Description of non-type female (NMB012_001).

Specimen preparation and condition. Specimen preserved in same manner as male holotype. Color. Carapace yellowish red 5YR 4/6. Abdomen light yellowish-brown 10YR 6/4. Cephalothorax. Carapace 8.13 long, 6.08 wide, hirsute with fine white setae as in male; lacks fringe. Foveal groove deep and slightly recurved. Tubercle absent. AER very slightly procurved, PER straight to slightly recurved. AME reduced in size, smaller than PME. Sternum moderately setose, STRl 4.49, STRw 3.43. Posterior sigilla small, widely separated; medial anterior sigilla relatively small, positioned laterally. ANTd with 6 teeth with posterior margin comprising 4 teeth. Palpal endites, ~25 cuspules, restricted to the anterior margin endites; labium lacks cuspules, LBw 1.28, LBl 0.97. Rastellum absent. Legs. Leg I: 5.69, 3.19, 3.84, 3.09, 2.30; leg IV: 4.29, 3.58, 5.15, 4.46, 2.53. Dense scopulae tarsus/metatarsus of Legs I/II, tarsus/tibia of pedipalp. Tarsus I with ~18 trichobothria arranged in a relatively tight row. PTLs 4, TBs 2. ITC small, sharply precurved; paired claws biserially dentate. Preening combs absent. Female specimen has numerous setae on carapace and legs modified as spatulate (Fig. 4). Spermathecae bulbs thin and sinuous (Fig. 9). Apical segment of PLS short, domed.

Remarks.

The female specimen described herein is from a locality some distance from where the male specimens and male holotype/paratypes were collected (formally designated as the type locality). As such we do not describe the female as a paratype so as not to confuse the type locality or the identity of the species if the female specimen is eventually discovered to be a different species - acknowledging that mygalomorph spiders are known to be highly endemic with considerable species crypsis (see Bond & Stockman 2008). Nevertheless, we are reasonably confident that these specimens are conspecifics given similarities in morphology (e.g., size of the PMEs), habitat, and an explicit morphological species concept (applied herein).

Additional material examined.

Male specimens (12) collected in pitfall trips in vicinity of the type locality at Gobabeb, deposited in the BME. Single female specimen (NMB012_001) from the Erongo Region, Namibia, in vicinity of Intersection C39 and Huab River, - 20.36035 14.19186898, coll. J. Bond 19.ix.2013, deposited in BME.

Distribution.

Known only from the Erongo Region, Namibia.