Heptathela australis (Ono, 2002)

Schwendinger, Peter J. & Ono, Hirotsugu, 2011, On two Heptathela species from southern Vietnam, with a discussion of copulatory organs and systematics of the Liphistiidae (Araneae: Mesothelae), Revue suisse de Zoologie 118 (4), pp. 599-637 : 602-606

Heptathela australis (Ono, 2002) Figs 1-20, 55-58, 67

Songthela australis Ono, 2002a: 120-122 , figs 1-8 (description of female).

Heptathela australis (Ono, 2002) .- Platnick, 2011 (transferred without explanation in an earlier version of that online catalogue; this generic placement is maintained here).

MATERIAL EXAMINED: NSMT-Ar 9617 (1 male) , IEBR, without registration numbers (1 male and 1 female) , MHNG, without registration numbers (all other specimens), sample SV- 03/18; 9 males (matured early June 2004, 2.VII.2004, 30.VII.2004, 30.VI.2006, 10.V.2007, 24.V.2007, May 2007, 17.IV.2008, 27.IV.2008), 10 females and 1 juvenile; near Dambri Waterfall , about 18 km N of Bao Loc, 11°38’42”N, 107°44’37”E, 850 m; 1.-2.IX.2003; leg. P. J. Schwendinger. – MHNG, without registration number, sample SV-03/17; 1 male; Lam Dong Province, off the road from Da Hoa (= Da Huoai) to Bao Loc , about 13 km SW of Bao Loc, 11°27’20”N, 107°43’04”E, 690 m; 31.VIII.2003; leg. P. J. Schwendinger.

EMENDED DIAGNOSIS: Males of H. australis differ from those of H. tonkinensis by a narrower cymbium with a longer and narrower elongate proventral-distal projection; paracymbium much longer and basally much narrower, almost forming a right angle with the cymbium; an unpigmented and unsclerotised zone present distoventrally on cymbium; marginal tegular apophysis much longer and pointed, terminal tegular apophysis with its dorsal edge much less projecting and less dentate; contrategulum with two distal edges running parallel to each other: an outer sharp edge and an inner dentate edge; the sharp edge with a pronounced, beak-like extension prolaterally, the dentate edge not connected with the isolated denticles in the ventro-proximal part of the contrategulum; conductor shorter, situated close to the embolus, its apex without denticles; embolus longer. Females of H. australis are similar to those of H. hangzhouensis , differing by larger posterior “bursae” (= receptacular clusters) (see Ono, 2002a: 120, referring to Song & Haupt, 1984: fig. 3c-d). Another distinction is found in the shape of the bursa copulatrix in dorsal and ventral view: longer and trapezoidal or triangular in H. australis , shorter and rectangular in H. hangzhouensis .

DESCRIPTION OF MALE (matured 10.V.2007): Colouration in alcohol (live specimens distinctly darker): Ground colour of carapace light brown, with indistinct dark brown W-shaped pattern behind dark ocular mound and with dark brown band along anterior and lateral margins. Opisthosoma cream, mottled with light grey; tergites uniformly light greyish brown; sternites light orange-brown; spinnerets cream. Chelicerae light brown distally, cream proximally. Legs and palps dorsally uniformly light reddish brown except for a dark red-brown distal zone of the cymbium (not including cymbial projection); no dark annulation present. Ventral side of body and limbs generally lighter than dorsal side.

Total length 15.2. Carapace 6.4 long, 5.2 wide, set with a few short, peg-like hairs (with blunt tips) on margin (mostly anteriorly and posteriorly), behind ocular mound and on coxal elevations, only few longer pointed hairs running over ocular mound in a longitudinal row. Eye group 0.92 long, 1.05 wide. Eye sizes and interdistances: AME 0.04, ALE 0.59, PME 0.30, PLE 0.53; AME-AME 0.09, AME-ALE 1.14, PME-PME 0.04, PME-PLE 0.12, ALE-PLE 0.08. MOQ 0.43 long, front width 0.19, back width 0.46. Labium 0.4 long, 1.2 wide. Sternum 2.5 long, 2.2 wide (1.2 on ventral surface). Anterior margin of sternum distinctly elevated, thus a deep suture present between sternum and labium. Maxillae 2.2 long, 1.4 wide. Promargin of cheliceral groove with 10 small teeth on each chelicera. Paired tarsal claws with 4-5 teeth; unpaired claws without denticles. Measurements of limbs: palp 11.4 (3.4 + 1.9 + 3.9 + 2.2); leg I 18.7 (5.1 + 2.4 + 3.8 + 4.9 + 2.5); leg II 19.1 (5.0 + 2.4 + 3.7 + 5.3 + 2.7); leg III 20.4 (4.9 + 2.5 + 3.8 + 6.2 + 3.0); leg IV 26.5 (6.5 + 2.7 + 5.0 + 8.6 + 3.7). “Tibial spurs” (sensu Platnick & Goloboff, 1985) absent on all legs. Opisthosoma 5.7 long, 3.6 wide; posterior margin of genital sternite (= sternite of second opisthosomal segment) widely rounded, with slightly protruding median part (Fig. 1).

Palp (Figs 2-15) with a quite long and narrow cymbial projection (Fig. 2); distoventral zone of cymbium (below subtegulum) unpigmented and unsclerotised, formed by extension of unpigmented and unsclerotised inner (retrolateral distal) side of cymbium onto its ventral side (Fig. 3); paracymbium relatively long and narrow, with only indistinct proximal tubercle; cymbium and paracymbium almost at right angles (Fig. 3). Tegulum with two large apophyses: 1) marginal apophysis long, pointed, distad-directed, with a sharp edge running across it from prolateral to retrolateral side (Figs 2-4); 2) terminal apophysis retrolaterad- and slightly proximaddirected, with an abruptly narrowed and slightly distad-bent apex (Fig. 3), dorsal side of apophysis only moderately extended and carrying a low, weakly dentate edge, dorsal and ventral sides of apophysis almost parallel to each other (Figs 3, 5, 10-14); edges of both apophyses not in contact with each other. Contrategulum with a few isolated denticles ventro-proximally and with two parallel distal edges, the outer one sharp, the inner one finely dentate, both uniformely pigmented (Fig. 3); sharp edge prolaterally abruptly truncate, with a beak-like extension pointing toward marginal apophysis of tegulum (Fig. 2). Conductor arising ventro-proximally on embolus (= bulbal sclerite III), its proximal half fairly wide and fused with base of embolus, its distal half free, blade-like, with continuously narrowing sides and pointed apex (Figs 3-9). Embolus largely sclerotised, prolateral half strengthened by numerous longitudinal ribs (Figs 2-5); terminal fringe around opening of sperm duct (= spermophore) hyaline and finely serrate (Figs 3-4, 6, 8-9).

DESCRIPTION OF FEMALE: See Ono (2002a: 120-122, figs 1-8). Anterior margin of sternum elevated as in male, thus also with a deep suture between sternum and labium. “Tibial spurs” present on legs I-III. Vulva as in Figs 16-19, 55-58.

VARIATION: Range of measurements in males (n=10) and in newly collected females with clearly developed vulva (n=10; in parentheses): body length 12.7-17.6 (15.3-24.1), carapace length 5.4-7.1 (6.0-9.4), carapace width 4.2-6.2 (4.8-8.1). Variation in the overall shape of the vulvae of four new females is not strongly pronounced (Figs 16-18, 55). The largest female (only it) has a dark brown spot on the ventral wall of the bursa copulatrix, and several small sclerotised vesicles (as the ones on the receptacular clusters), penetrated by gland pores, sitting on the dorsal wall of the bursa copulatrix, in between the four receptacular clusters (Fig. 16). The latter character can be an atavism (see Discussion: evolution of female copulatory organs). In one female the posterior margin of the genital sternite is indented (probably from an injury sustained in an earlier instar; Fig. 20). For variation in the shape of the palpal organ, see Figs 6-9 (conductor), Figs 3, 10 (marginal tegular apophysis) and Figs 5, 10-14 (terminal tegular apophysis). One male has a proximally narrow paracymbium (Fig. 15). The number of isolated denticles ventro-proximally on the contrategulum varies from 2-7.

FIGS 1-15

Heptathela australis (Ono, 2002) , male (mature 10. V.2007) from the type locality (1-6), five other males from the type locality (7, 11; 9; 10; 12; 13), male from Dao Hoa - Bao Loc (8, 14- 15). (1) Posterior margin of genital sternite, ventral view. (2) Distal part of left palp, prolateral view. (3) Same , ventral view. (4) Same , retrolateral view. (5) Same , distal view. (6, 8-9) Embolus and conductor, proventral view. (7) Conductor, proventral view. (10) Marginal and terminal apo- FIGS 16-20

Heptathela australis (Ono, 2002) . (16) Vulva of largest female, dorsal view; dorsal and lateral walls of genital atrium not shown. (17-18) Bursae copulatrices of two other females, dorsal view. (19) Schema of vulva, lateral view (the oviduct is actually anterodorsad- and not posterodorsaddirected). (20) Posterior margin of deformed genital sternite, ventral view. BC = bursa copulatrix; GA= genital atrium; Od = oviduct; RC = receptacular cluster. Scale lines 1.0 mm.

RELATIONSHIPS: Despite pronounced differences in female copulatory organs, H. australis appears most closely related to N. nui sp. n. Their palps share distinct synapomorphies, and both species occur in the same mountain range, about 80 km apart. Their closest known relatives are H. tonkinensis and H. tomokunii from northern Vietnam, but more closely related species most likely await discovery in the mountains between Da Lat and Hanoi. The male of the geographically closer H. cucphuongensis (from south of Hanoi) is unknown and therefore the relationships of this species are not yet clear.

physis of tegulum, ventral view. (11-14) Terminal apophysis of tegulum, ventral view. (15) Outline of paracymbium, ventral view. Co = conductor; CP = cymbial projection; CT = contrategulum; Cy = cymbium; DE = dentate distal edge of contrategulum; DT = dorsal extension of terminal apophysis of tegulum; E = embolus; MA = marginal apophysis of tegulum; PC = paracymbium; PE = prolateral extension of sharp distal edge of contrategulum; SE = sharp distal edge of contrategulum; ST = subtegulum; T = tegulum; TA = terminal apophysis of tegulum; Z = unpigmented distoventral zone of cymbium. Scale lines 1.0 mm.

DISTRIBUTION: Known only from two localities near Bao Loc village in southern Vietnam.

BIOLOGY: The mature male was discovered when scraping leaf litter from the floor of an evergreen broadleaf forest. He probably had left his burrow in search of females and was taking temporary shelter in the leaf litter during the day. All other spiders were extracted from their burrows in sun-exposed earth banks (with little vegetation) on one side of a dirt road in an old secondary forest. None of the burrows inspected at the beginning of September contained mature males, and by then the mating period was probably at its end.

All burrows were closed with a single trapdoor that had its hinge on the upper side of the entrance; the lower rim of the burrow entrance was slightly protruding. Trapdoors of females were up to 3.3 cm wide and 2.5 cm long; those of penultimate males 2.0-2.3 and 1.5-1.8 cm, respectively. No spiders were seen when their doors were carefully opened with forceps for inspection. They were resting in the depth of their burrows and could not be provoked to come to the entrance by inserting a flexible grass stem and disturbing them (which often works for extracting spiders of the genus Liphistius ). All these spiders had to be dug up. Large and medium-sized spiders (including adult males) react to disturbance by repeatedly raising their body above the ground while the leg tarsi remained on the ground (a behaviour called “tiptoeing”) and by spreading their chelicerae, as large Liphistius also do. Four egg cases (2.5-3.5 cm in diameter and 1.4-1.9 cm high) were built between the end of November and late December 2003. Three of them held clusters of 129-164 beige or light yellow eggs wrapped in a thin skin made of a coagulated vulval secretion and some fine silken threads (as present in all liphistiid egg cases examined, but less distinct in Liphistius ), resting on a mesh of fine threads above the bottom of the inner chamber of the egg case. Ninety-nine third (or later?) instar juveniles were taken from the fourth egg case in mid-April 2004. Five of them were males that reached maturity in June 2006, May 2007 and April 2008, which is presumably earlier in the year than in nature (since the adult male was found at the end of August). Development from eggs to adult males in captivity thus took between one and a half years and three years and four months. Females which laid eggs between November and December moulted in the following March, May and June.

Three of the large females, which were collected in the field and subsequently laid eggs in Geneva, each carried more than 50 ectoparasitic mites of different instars on their prosoma. These mites were usually sitting on the carapace, but when disturbed took shelter on the ventral side, between the coxae and the sternum, and between the prosoma and the opisthosoma. They pierced the carapace at numerous places and left clearly visible dark round scars that make the spiders look as if they had measles (Fig. 67). The carapace, a quite strongly sclerotised plate, is an unlikely place for sucking body fluids. Surprisingly, no scars or any other signs of damage are visible on the soft membranes between the sclerites of the prosoma or on the opisthosoma.