Tetralycosa rebecca Framenau & Hudson 2017, sp. nov.

Tetralycosa rebecca sp. nov.

urn:lsid:zoobank.org:act: AC1DBF8D-E25C-470A-BA2F-9ADE16402C3C

Figs 18 E–H; 20A–C; 21

Diagnosis

Tetralycosa rebecca sp. nov. is the only species within the genus in which the anterior median eyes are smaller than the anterior lateral eyes. In addition, males of T. rebecca sp. nov. differ from all other males of Tetralycosa by a straight basal margin of the tegular apophysis, which forms an arch in the other species. The female epigyne is most similar to that of T. floundersi sp. nov., however, the posterior transverse part is much wider than in the latter species.

Etymology

The specific epithet is a noun in apposition and refers to the type locality, Lake Rebecca, in Western Australia.

Type material

Holotype

AUSTRALIA: ♂, Western Australia, Lake Rebecca, 15 km N of Yindi Station, 30°15′40″ S, 122°29′00″ E, 11 Mar. 1996, P. Hudson leg. (SAM NN21913).

Paratype

AUSTRALIA: ♀, data as holotype (SAM NN21914).

Description

MEASUREMENTS. ♂ holotype, SAM NN21913 (♀ paratype, SAM NN219414): TL 10.25 (10.53), CL 5.73 (5.36), CW 4.04 (3.57). Eyes: AME 0.17 (0.19), ALE 0.25 (0.24), PME 0.71 (0.73), PLE 0.64 (0.70). Row of eyes: AE 1.60 (1.50), PME 1.93 (2.07), PLE 2.68 (2.77). Sternum length/width: 2.73/2.26 (2.26/1.97). Labium (length/width) 0.83/0.92 (0.88/0.89). AL 4.42 (5.73), AW 3.38 (4.32). Legs: Lengths of segments (femur + patella/tibia + metatarsus + tarsus = total length): Pedipalp 2.26+2.43+ – +1.82 = 6.51, I 5.08+5.17+4.79+1.88 = 16.92, II 4.89+5.26+5.455+1.97 = 17.57, III 4.61+4.89+5.55+2.07 = 17.12, IV 5.45+5.83+6.67+2.35 = 20.25 (Pedipalp 1.88+1.97+ – +1.60 = 5.45, I 3.85+4.23+3.29+1.69 = 13.06, II 3.76+4.23+3.67+1.69 = 13.35, III 3.76+4.14+3.95+1.88 = 13.73, IV 4.42+5.17+5.08+2.16 = 16.83).

VARIATION. Only known from holotype male and paratype female.

Male (based on holotype, SAM NN21913)

CARAPACE (Fig. 18E). Cephalic area highest in lateral view and steep vertical slopes in frontal view; brown, with indistinct darker radial pattern; some indistinct lighter patches above margins and indistinctly lighter around fovea; covered with mainly brown setae, but white setae towards margins and between and around PE; few brown bristles around PME; eight long bristles below AE; one long bristle between AME.

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

CHELICERAE. Orange-brown, covered with mainly white setae, but some brown setae apically; three promarginal teeth with the median largest; left chelicera with three retromarginal teeth of equal length, right chelicera with four retromarginal teeth, the second basal one very small.

STERNUM (Fig. 18F). Yellow-brown with grey pigmentation; covered with light brown setae that increase in length towards margins.

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

PEDIPALPS (Fig. 20 A–B). Tegular apophysis curved with straight basal margin (Fig. 20A); terminal apophysis not dissected, only known from single male.

ABDOMEN. Dark olive-grey with indistinct light lanceolate heart mark in anterior half; one pair of light spots in anterior half, two pairs of spots in posterior half; covered with mainly grey setae (Fig. 18E). Venter uniformly yellow with white setae. Spinnerets brown (Fig. 18F).

LEGS. Leg formula IV>II>III>I; yellow-brown, lighter ventrally. Femora with grey pigmentation apically, tibiae darker apically and basally, metatarsi and tarsi of leg I and II darkest; hair-like setae ventrally on metatarsi I and II and tibiae II. Spination of leg I: femur: three dorsal, four retrolateral (only three on right leg), two apicoprolateral; 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 NN219414)

CARAPACE (Fig. 18G). Uniformly dark brown with indistinct darker radial pattern; lateral band reduced to two small light spots above leg II and III; covered with brown setae, longer white setae in eye field; few light brown bristles around PME; eight long bristles below AE; one long bristle between AME.

EYES. Row of AE shorter than row of PME; row of AE slightly procurved; ocular trapeze wider than long.

CHELICERAE. Colour, setae and dentition as male.

STERNUM (Fig. 18H). Light brown with grey, irregular pigmentation; covered with brown setae that increase in length towards margin.

LABIUM. As male.

ABDOMEN. Uniformly dark olive-grey with an indistinct lanceolate heart mark in anterior half; two pairs of light spots in posterior half; covered with grey setae (Fig. 18G). Venter yellow-grey, slightly darker centrally; covered with light grey setae. Spinnerets light brown (Fig. 18H).

EPIGYNE. Ventral view (Fig. 20C): anterior margin with two sclerotised protrusions, posterior transverse part forms an arch with lateral ends pointing anterolateral. Dorsal view: not dissected, only known from single female.

LEGS. Leg formula IV>III>II>I. Femora light brown, apically and dorsally darker, light double bands dorsally; tibiae light brown, basally and apically darker; metatarsi light brown with three darker annulations; tarsi light brown. Femora ventrally covered with white setae, metatarsi I and II ventrally with scopulae. Spination of leg I: femur: three dorsal, one retrolateral (right leg two), two apicoprolateral; tibia: one apicoventral pair, two prolateral; metatarsus: three ventral pairs, one apicoventral.

Life history and habitat preferences

The male and female types of T. rebecca sp. nov. were found on the surface of a salt lake in March.

Distribution

Only known from the type locality Lake Rebecca, south-western Western Australia (Fig. 21).