Blakistonia gemmelli, Harrison & Rix & Harvey & Austin, 2018

Harrison, Sophie E., Rix, Michael G., Harvey, Mark S. & Austin, Andrew D., 2018, Systematics of the Australian spiny trapdoor spiders of the genus Blakistonia Hogg (Araneae: Idiopidae), Zootaxa 4518 (1), pp. 1-76 : 38-40

Blakistonia gemmelli , sp. n.

( Fig. 13 A–L)

Type material. AUSTRALIA: South Australia: Holotype male, Weetootla Well, Flinders Ranges , 30°30’00”S, 139°15’00”E, 9 May 1989, pitfall trap, D. Hirst (SAM NN20097 ). Paratypes: 1 male, same data ( SAM NN20098 ) ; 1 male, same data except 30°29’00”S, 139°13’00”E, 8 May 1989 .

Diagnosis. Males of B. gemmelli can be distinguished from those of B. maryae , B. plata , B. birksi , B. newtoni , B. hortoni , B. parva , B. maryae , B. olea , B. tariae , B. carnarvon and B. raveni by the prolateral clasping spurs on tibia I, each with raised cuticular bases and bearing multiple terminal peg-like macrosetae ( Fig. 13 G–I); from those of B. bella by the lack of a dorsal abdominal cardiac stripe ( Fig 13A ); from those of B. pidax by the thick spine-like spinules on the cymbium ( Fig. 13 J–L); from those of B. tunstilli by the spinules on the palpal tibia being similar in size or only slightly shorter compared to those on the RTA ( Fig. 13J, L ); from those of B. emmottorum by the square eye group ( Fig. 13D ); and from those of B. aurea by the short and stout RTA, with the field of RTA spinules extending only slightly onto the tibia ( Fig. 13J ), and by the strong abdominal pattern ( Fig 13A ). Females are unknown.

Description. Holotype male (SAM NN20097). Small idiopid spider (total length 7.8).

Colour (in ethanol; Fig. 13 A–C): Carapace, legs and pedipalp uniform pale golden orange-brown ( Fig. 13A ); sternum, labium and maxillae very similar; chelicerae darker golden-brown ( Fig. 13E, F ); abdomen same golden orange-brown with pattern of seven mottled chevrons; first chevron large and triangular second chevron about half width of first, remaining five chevrons split in centre, not continuous ( Fig. 13A, C ).

Cephalothorax: Carapace 3.6 long, 2.9 wide, 2.5 high, 1.2 times longer than wide; oval ( Fig. 13A ), caput low, ocular area raised ( Fig. 13C ); cuticle smooth, with pits outward from fovea and both sides of caput; fovea straight; row of sparse setae between fovea and eye group; carapace otherwise with few smaller fine setae, concentrated and form fringe around lateral margins; median clump of thickened setae on clypeus ( Fig. 13D ). Length of median clypeus less than 1.0; anterior margin slightly convex. Eye group 1.1 wide, 0.7 long, 0.4 of carapace width; anterior eye row strongly procurved, PLE–PLE/ALE–ALE ratio 0.9; posterior eye row slightly procurved; AME only slightly smaller than ALE and separated by about ALE diameter; ALE and PLE separated by about twice PLE diameter; PME pale, less than half of AME and only slightly smaller than PLE, and separated from PLE by less than its own diameter ( Fig 13D ). Labium without cuspules ( Fig. 13F ). Sternum 1.9 long, 1.7 wide, evenly setose ( Fig. 13E ). Maxillae with 6 (left) and 4 (right) cuspules ( Fig. 13E, F ).

Legs: setose and spinose; tarsi I, II ventrally swollen; tarsi and distal metatarsi I, II weakly scopulate only ventrally ( Fig. 13 G–I). Paired tarsal claws: leg I p5 (2 large, 3 small) r5 (3 large, 2 small); leg II p2 (2 large), r2 (2 large); leg III p4 (2 large, 2 small), r5 (1 large, 4 small); leg IV p3 (3 large), r4 (3 large, 1 small).

Spination: Tibia I with prolateral clasping spurs, both spurs with 2 terminal peg-like macrosetae ( Fig. 13 G–I), r2; metatarsus p1. Leg II: tibia p1, r4; metatarsus p1, r5. Leg III: (right) patella r3; tibia p3, r1; metatarsus p7, r7; tarsus p4. Leg IV: tibia p3, r4; metatarsus p4, r6; tarsus p4, r6.

Leg and pedipalp measurements: Length of legs IV> II> I> III. Leg I: femur 3.1, patella 1.5, tibia 2.3, metatarsus 2.0, tarsus 1.5, total = 10.4. Leg II: femur 3.3, patella 1.6, tibia 2.4, metatarsus 2.1, tarsus 1.5, total = 10.9. Leg III: femur 2.8, patella 1.2, tibia 2.0, metatarsus 2.2, tarsus 1.6, total = 9.8. Leg IV (right): femur 3.6, patella 1.6, tibia 3.5, metatarsus 3.2, tarsus 2.0, total = 13.9. Pedipalp: femur 1.9, patella 0.7, tibia 1.7, tarsus 0.9, total = 5.2.

Pedipalp: Patella with thickened ventral setae; tibia short, swollen, RTA very short,pointed, with several setae and covered in short, dense spinules from just over half of the distance between base of apophysis and distal tibia, becoming very sparse towards dstal tibia; long, erect setae on ventral tibia; bulb uniform, globular; embolus simple, slender, tapering, tip slightly twisted, only slightly longer than length of bulb; cymbium covered in rows of short spinules, becoming longer closer to distal edge ( Fig. 13 J–L).

Abdomen: Setose, oval, dorsal sigilla not evident; 4.2 long, 2.9 wide ( Fig. 13A ).

Variation (n=3): Carapace 3.1–3.6 long, 2.8–2.9 wide, no labial cuspules. Spination: Leg I: tibia r2–5; metatarsus p0–1, r0–3. Leg II: tibia p1–2, r3–4; metatarsus p1–2, r 3–5; tarsus r0–1. Leg III: patella p3; tibia p1–3, r2–3; metatarsus p3–8, r6–8; tarsus p2–4, r0–3. Leg IV: tibia p0–3, r0–4; metatarsus p4–11, r3–6; tarsus p3–8, r2– 6.

Etymology. This species is named in honour of Mike Gemmell, for his long-term interest in trapdoor spiders.

Distribution. Blakistonia gemmelli is known only from Weetootla Well, in the Flinders Ranges ( Fig. 31 ).

Remarks. One specimen of B. aurea has also been found at Weetootla Well (SAM NN20096).

Figures

FIGURE 13. Blakistonia gemmelli sp. n., holotype male (SAM NN20097): A, habitus, dorsal view; B, habitus, ventral view; C, habitus, lateral view; D, eye group, dorsal view; E, sternum, ventral view; F, maxillae and labium, ventral view; G, left leg I, prolateral view; H, left leg I, mating spur, prolateral view; I, left leg I, ventral view; J, left pedipalp, prolateral view; K, left pedipalp, retrolateral view; L, left pedipalp, proventral view. Scale bars = 2 mm (A, G), 1 mm (J).

FIGURE 31. Distributions of Blakistonia species: B. bassi sp. n. (black circle), B. hortoni sp. n. (white squares), B. bella sp. n. (white circles), and B. gemmelli sp. n. (black square).