Tetralycosa adarca sp. nov.

urn:lsid:zoobank.org:act: 84A3D674-CC80-44EA-AFC0-53D2567FCE0B Figs 22 A–D; 23A–E; 25 Diagnosis

Males of T. adarca sp. nov. differ from all other males of Tetralycosa by the shape of the tegular apophysis, which has a rounded meso-basal flap. Females are not distinguishable from T. halophila sp. nov., T. williamsi sp. nov. and T. eyrei due to a very similar genital morphology although the epigyne of T. halophila sp. nov. and T. williamsi sp. nov. appears to be relatively wider than in T. adarca sp. nov. and T. eyrei . However, there is only limited information on intraspecific variation, as most species are only known from one to a few individuals.

Etymology

The specific epithet is a noun in apposition from the Latin ‘ adarca ’, salt coating on a marsh plant, and refers to the salt lake environment that these spiders occupy.

Type material

Holotype

AUSTRALIA: ♂, South Australia, Lake Acraman, 32°05′24″ S, 135°31′20″ E, 10 Jul. 1995, P. Hudson leg. (SAM NN21882).

Paratype

AUSTRALIA: ♀ with egg sac, South Australia, Lake Acraman, 32°01′10″ S, 135°21′00″ E, 3 Mar. 1993, P. Hudson leg. (SAM NN21732).

Other material examined

AUSTRALIA, South Australia: 1 ♂, 1 ♀, Lake Gairdner, 32°07′41″ S, 135°53′19″ E (SAM NN21721, NN21888); 1 ♀ with egg sac, Lake Gairdner North, 31°13′10″ S, 135°56′00″ E (SAM NN21777).

Description

MEASUREMENTS. ♂ holotype, SAM NN21882 (♀ paratype, SAM NN21732): TL 15.32 (16.17), CL 7.99 (8.08), CW 6.02 (5.73). Eyes: AME 0.44 (0.43), ALE 0.30 (0.33), PME 1.09 (1.05), PLE 0.96 (0.99). Row of eyes: AE 2.16 (2.16), PME 2.91 (2.91), PLE 4.14 (4.14). Sternum length/width: 3.57/2.91 (3.48/2.73). Labium length/width: 1.18/1.17 (1.17/1.18). AL 7.33 (7.52), AW 4.70 (5.64). Legs: Lengths of segments (femur + patella/tibia + metatarsus + tarsus = total length): Pedipalp 3.57+4.58+ – +3.15 = 11.30, I 7.24+7.90+7.14+2.44 = 24.72, II 7.33+7.90+7.33+2.44 = 25.00, III 7.05+7.71+7.90+2.54 = 25.20, IV 8.18+9.21+9.78+2.82 = 29.99 (Pedipalp 3.20+2.82+ – +2.16 = 8.18, I 6.67+7.05+5.73+2.16 = 21.61, II 6.58+6.96+5.92+2.16 = 21.62, III 6.11+6.58+6.58+2.26 = 21.53, IV 7.80+8.27+8.55+2.63 = 27.25).

VARIATION. In addition to the type material, only one further male (SAM NN21888, TL 18.75, CL 10.35, CW 7.65) and female (SAM NN21777, TL 19.50, CL 9.75, CW 7.65) were found.

Male (based on holotype, SAM NN21882)

CARAPACE (Fig. 22A). Cephalic area highest in lateral view and steep vertical slopes in frontal view; uniformly dark reddish-brown with indistinct darker radial pattern; covered with dark brown setae,

white towards margins and anteriorly of fovea and in eye region; brown macrosetae around PE; ca 12 long bristles below AE; one long bristle between AME.

EYES. Row of AE of shorter than row of PME; row of AE strongly procurved.

CHELICERAE. Reddish-brown, dark brown apically; covered with white setae basally; three promarginal teeth with the median largest; three retromarginal teeth of similar size (right chelicerae with additional small apical tooth).

STERNUM (Fig. 22B). Dark reddish-brown with grey pigmentation; covered with brown setae that are longer towards margins.

LABIUM. Brown, laterally darker; front end truncate and white.

PEDIPALPS (Fig. 23 A–C). Tegular apophysis with a meso-basal rounded flap (Fig. 23A); upper edge of terminal apophysis shaft bend about half-way; embolus relatively thick and straight (Fig. 23C).

ABDOMEN. Dorsally yellow-brown with indistinct lanceolate heart mark in anterior half; olive-grey mottled pattern in anterior half that forms transverse bars in posterior half; covered with grey setae (Fig. 22A). Ventrally yellow-brown with olive-grey central patch that dissolves with yellow-brown spots laterally; three longitudinal bands of dense white setae. Spinnerets light brown (Fig. 22B).

LEGS. Leg formula IV>II>III>I; brown. Femora of legs III and IV with two dark ventral annulations; tibiae, metatarsi and tarsi of leg I and II dark brown. Spination of leg I: femur: three dorsal, two apicoprolateral, four retrolateral; patella: one prolateral, one retrolateral; tibia: two dorsal, three ventral pairs, two prolateral, two retrolateral; metatarsus: three ventral pairs, two prolateral, two retrolateral, one apicoventral, one apicoprolateral, one apicoretrolateral.

Female (based on paratype, SAM NN21732)

CARAPACE AND EYES (Fig 22C). As male.

CHELICERAE. Dark reddish-brown, setae and dentition as male (including the fourth apical tooth on right retromargin).

STERNUM (Fig. 22D). As male, but with less grey pigmentation.

LABIUM. As male.

ABDOMEN. Poorly preserved; dorsal pattern as male but lighter (Fig. 22C). Venter light yellow-brown with a large grey central patch through darker setae. Spinnerets as male (Fig. 22D).

EPIGYNE. Ventral view (Fig. 23D): circular atrium with anterior notch. Dorsal view (Fig. 23E): spermathecal heads cylindrical with indistinct spermathecal stalks.

LEGS. Leg formula IV>II>I>III. Colour pattern as male; scopulae on metatarsi and tarsi of legs I and II. Spination of leg I: femur: three dorsal, four retrolateral, two apicoprolateral; patella: one prolateral, one retrolateral; tibia: one dorsal, three ventral pairs, two prolateral, two retrolateral; metatarsus: three ventral pairs, two prolateral, two retrolateral, one apicoventral, one apicoprolateral, one apicoretrolateral.

Life history and habitat preferences

Adult spiders were found on the surface of a salt lake in March and July. Both females were carrying an egg sac.

Distribution

Known from Lake Acraman and Lake Gairdner, South Australia (Fig. 25).