Epigastrina typhlops Rix & Harvey, 2010

Rix, Michael & Harvey, Mark, 2010, The spider family Micropholcommatidae (Arachnida: Araneae: Araneoidea): a relimitation and revision at the generic level, ZooKeys 36 (36), pp. 1-321 : 45-46

Epigastrina typhlops Rix & Harvey , sp. n.

urn:lsid:zoobank.org:act:39623469-D1A5-4EDD-974A-1F3AD909EBC8

Figs 63E , 65–66 , 213

Type material. Holotype male: Kubla Khan (MC-1), Mole Creek karst, Tasmania, Australia, from sheet web with vertical stay lines in cracks of wall above pool, near lower entrance (dark zone), 41°33'12"S, 146°16'52"E, 24.X.1990, S. Eberhard ( AMS KS29793 ).

Paratypes: Allotype female, same data as holotype ( QVM 13 : 12765) .

Etymology. The specific epithet is derived from the Greek ‘typhlos’, meaning ‘blind’ ( Brown 1956), and refers to the absence of eyes in this species.

Diagnosis. Males and females of Epigastrina typhlops can be distinguished from all other described congeners by the complete absence of eyes ( Fig. 65C ).

Description. Holotype male: Total length 1.18. Carapace 0.53 long, 0.39 wide. Abdomen 0.70 long, 0.47 wide. Leg I femur 0.48. Cephalothorax, legs very pale tan-yellow; abdomen pale cream. Carapace raised anteriorly, not fused to sternum except around petiole; dorsal surface of pars cephalica slightly convex in lateral view. Eyes absent. Chelicerae each with large, bulging anterior projection; promargin with three peg teeth. Legs relatively short (leg I femur-carapace ratio 0.91); distal, prolateral macroseta present on tibia I. Abdomen oval, covered with hair-like setae; dorsal scute large, indistinct, covering most of dorsal surface of abdomen; lateral sclerotic strips absent. Pedipalpal patella with retrolaterally-directed, hooked lRPA and ornate, ridged cuticular microstructure; tegulum large, bulging posteriorly, with excavate ETR and very large, divergent, fleshy medial conductor bearing rod-like prolateral process and massive, fleshy retrolateral process; embolus short (length <5× width), spur-like, distally hooked, situated between divergent processes of conductor ( Fig. 66 ).

Allotype female: Total length 1.12. Carapace 0.49 long, 0.40 wide. Abdomen 0.76 long, 0.55 wide. Leg I femur 0.43. Cephalothorax, legs very pale tan-yellow; abdomen pale cream, with darker tan-yellow epigyne. Carapace raised anteriorly, not fused to sternum except around petiole; dorsal surface of pars cephalica slightly convex in lateral view. Eyes absent. Chelicerae without bulging anterior projections; promargin without peg teeth. Legs relatively short (leg I femur-carapace ratio 0.88); macrosetae absent. Abdomen oval, covered with hair-like setae; dorsal scute and lateral sclerotic strips absent. Pedipalp entire, five-segmented. Epigyne heavily sclerotised externally, with distinctive, wedge-shaped epigastric plate ( Fig. 65D ); spermathecae globular, connecting to parallel, filiform insemination and fertilisation ducts ( Fig. 63E ).

Distribution. Known only from the cave Kubla Khan in the Mole Creek karst of north-central Tasmania (Fig. 213).

Remarks. Epigastrina typhlops is a highly troglomorphic and completely blind species, otherwise very similar to E. fulva and E. loongana .

Figures

Figure 63. Epigastrina species, female epigynes and receptacula. A–B E. fulva (Hickman) from Mount Wellington, Tasmania: A external epigyne, ventral view, showing the very large epigastric plate B cleared receptacula, dorsal view. C–E external epigynes, ventral view, at scale-identical size for comparison: C E. fulva from Mount Wellington, Tasmania D holotype E. loongana sp. n. from the Loongana karst, Tasmania; E, allotype E. typhlops sp. n. from the Mole Creek karst, Tasmania. Arrows indicate the trajectory of insemination and proximal fertilisation ducts. Scale bars = 0.065 mm (65 µm).

Figure 65. Epigastrina typhlops sp. n. from the Mole Creek karst, Tasmania. A, C holotype male (AMS KS29793): A habitus, dorsal view C cephalothorax and right pedipalp (left removed), antero-dorsal view. B, D allotype female (QVM 13:12765): B habitus, dorsal view D abdomen, ventral view. Note the pale body colouration and complete absence of eyes.

Figure 66. Epigastrina typhlops sp. n., holotype male from the Mole Creek karst, Tasmania (AMS KS29793): A left pedipalp, ventral view B left pedipalp, retrolateral view. Scale bar = 0.065 mm (65 µm).