Namea nigritarsus, Rix & Wilson & Harvey, 2020

Rix, Michael G., Wilson, Jeremy D. & Harvey, Mark S., 2020, The open-holed trapdoor spiders (Mygalomorphae: Anamidae: Namea) of Australia’s D’Aguilar Range: revealing an unexpected subtropical hotspot of rainforest diversity, Zootaxa 4861 (1), pp. 71-91 : 85-87

Namea nigritarsus sp. nov.

( Figs 8, 12 , 13 , 15a, b , 55–67 ) http://zoobank.org/?lsid= urn:lsid:zoobank.org:act:FAE2227F-8DE5-430E-8E6C-CE5526363071

Namea bunya Raven, 1984: 15 (in part; cited paratype specimens QMB S785 from Mount Mee ).

Namea excavans Raven, 1984: 29 (in part; cited paratype specimen QMB S830 from Mount Mee ).

Namea sp . ‘D’Aguilar’ Rix et al., 2020: 683 , 686, figs 2, 3, 105, 106, 108.

Type material. AUSTRALIA: Queensland: male holotype, Mount Glorious , pitfall trap, rainforest, 1987/88, R. Goundy ( QMB S111534 ) .

Other material examined. Australia: Queensland: 1 juvenile, D’Aguilar National Park, Mount Glorious, Maiala section, lower rainforest circuit, 27°19’54”S, 152°45’44”E, hand collected from burrow, rainforest, 10 April 2019, M. Rix, J. Wilson ( QMB S111458 DNA) ; 1 juvenile, same data except 2 February 2019 ( QMB S111375 DNA) ; 1 juvenile, D’Aguilar National Park, Mount Mee section, 27°05’10”S, 152°41’14”E, hand collected from burrow, rainforest, 532 m, 18 February 2019, M. Rix, J. Wilson ( QMB S111390 DNA) ; 1 juvenile, same data except The Mill Rainforest Walk , 27°04’54”S, 152°42’36”E, 293 m ( QMB S111398 DNA) ; 2 males, Mount Mee, Neurum Creek (GM99), pitfall trap, rainforest, 550 m, 13 Febraury– 30 August 1979, G. & S. Monteith ( QMB S785 ) ; 1 male, same data except (GM90), 26 February –26 June 1978 ( QMB S830 ) .

Diagnosis. Males of Namea nigritarsus can be distinguished from those of all other described congeners except N. bunya and N. nebo by the following combination of four characters: embolus long, reflexed and whip like ( Figs 65–67 ); retroventral margin of palpal tibia with single, isolated, proximal macroseta ( Figs 65, 66 ); tibia I with prolateral (p) macrosetae ( Figs 62, 64 ); and macroseta v1 on tibia I short, not reaching beyond ventro-distal margin of tibia I ( Fig. 64 ). Males can be further distinguished from those of N. bunya by the longer macroseta v1 on tibia I ( Fig. 64 ; cf. Rix et al. 2020, fig. 121); and from those of N. nebo by the shape of the palpal bulb, which is produced along its transverse axis and swollen near the base of the embolus ( Fig. 66 ; cf. Figs 78–80 ), the shallower, only slightly concave ventro-distal excavation anterior to macroseta v1 ( Fig. 64 ; cf. Fig. 77 ), and absence of a covering of downy, reflective setae on the carapace ( Figs 55, 57 ; cf. Figs 68, 70 ).

Females are unknown.

Description (male holotype): Total length 11.6. Carapace 5.3 long, 3.9 wide. Abdomen 4.9 long, 3.1 wide. Carapace ( Fig. 55 ) dark chocolate-brown and sparsely setose; lateral margins with fringe of anteriorly curved, porrect black setae, longest posteriorly; fovea straight. Eye group ( Fig. 58 ) rectangular, twice as wide as long, PLE–PLE/ALE–ALE ratio 1.0; AME separated by less than their own diameter; PME separated by 3.6 X their own diameter; PME and PLE almost contiguous. Maxillae each with field of ca. 50 cuspules confined to heel and inner proximal corner ( Fig. 59 ); labium without cuspules. Abdomen ( Figs 56, 61 ) oval, dark brown with course pale beige-brown marbled pattern dorsally, and pale beige-brown ventrally with finer dark brown mottling, the latter concentrated slightly anterior to spinnerets; covered with short, fine setae. Legs ( Figs 55, 62–64 ) dark tan-brown, with light scopulae on tarsi I–IV and distal half of metatarsi I–II; tibia I with 3 prodorsal, 2 prolateral, 3 proventral and 3 ventral macrosetae; macroseta v1 not reaching beyond ventro-distal margin of tibia I ( Fig. 64 ). Leg I: femur 4.1, patella 2.6, tibia 3.1, metatarsus 3.5, tarsus 2.3, total length 15.6. Leg I femur–tarsus/carapace length ratio 2.9. Pedipalpal tibia ( Figs 65–67 ) 2.7 X longer than wide, with isolated, proximal retroventral macroseta, 1 retrodistal macroseta, 1 dorsal macroseta, and 1 prodistal macroseta. Cymbium ( Figs 65–67 ) setose, distally cleft in retrolateral view, with distal scopula. Bulb ( Figs 65–67 ) produced along transverse axis and swollen near base of embolus, with long, whip-like, reflexed embolus arising from proventral base of bulb.

Etymology. The specific epithet is a noun derived from the Latin nigra (adjective: ‘black’), and the Latin tarsus (noun: ‘foot’), in reference to the dark colouration of the distal legs of this species in life ( Fig. 8 ).

Distribution. Namea nigritarsus is endemic to the D’Aguilar Range, where it is known from rainforest at Mount Glorious, Mount Mee ( Fig. 2 ) and possibly also Mount Nebo ( Fig. 9 ).

Remarks. This attractive species occurs in rainforest habitats over much of the D’Aguilar Range, where it has been recorded syntopically at various locations with a number of other species, including N. brisbanensis , N. gowardae and N. salanitri . The spiders are smaller than all of the aforementioned species, and are distinctive in life, with reddish legs and the appearance of black ‘socks’ on the tarsi and metatarsi ( Fig. 8 ). Burrows have been found in rainforest banks, and sometimes have silk extending out from the main entrance hole ( Fig. 12 ). Little is known of its biology or life history, other than that males appear to be active in autumn or winter.

Figures

FIGURE 13. Phylogeny of the genus Namea modified from Rix et al. (2020; fig. 2), inferred from a partitioned Bayesian analysis of that study’s ‘FULL’ dataset (151 taxa, 5,261 bp, 50% majority-rule consensus tree). Clades corresponding to 30 morpho-species OTUs are collapsed for the genus Namea (square brackets denote the number of specimens included in each clade), and nodes have a posterior probability of ≥ 0.98 unless otherwise stated. Seven species recorded from the D’Aguilar Range (south-eastern Queensland) are highlighted in enlarged bold text; note that specimens of an eighth species, N. gloriosa sp. nov., were not sequenced for this study.

FIGURES 4–12. Live habitus images and burrows of Namea from the D’Aguilar Range (south-eastern Queensland). 4–8, Live habitus images: 4, female N. brisbanensis Raven, 1984 from Gold Creek Reserve (note left leg IV missing); 5, paratype female N. gowardae sp. nov. from Mount Glorious; 6, female N. salanitri Raven, 1984 from Mount Mee; 7, female N. dahmsi Raven, 1984 from Clear Mountain; 8, subadult juvenile N. nigritarsus sp. nov. from Mount Glorious. 9–12, Burrow images: 9, burrow of unidentified Namea (N. nigritarsus sp. nov. or N. nebo sp. nov.; not collected) from Mount Nebo, with spider at entrance; 10, burrow of N. gowardae sp. nov. from Mount Glorious, with spider at entrance; 11, burrow of N. dahmsi from Clear Mountain; 12, burrow of N. nigritarsus sp. nov. from Mount Mee. Images 4–8, 10, 11 by M. Rix; 9, 12 by J. Wilson.

FIGURES 14–21. Comparative morphology of Namea from the D’Aguilar Range (south-eastern Queensland); each figure for each species depicts (a) the male tibia I in standardised prolateral view, (b) the male pedipalp in retrolateral view, +/- (c) the female cleared genitalia in dorsal view (if known): 14, N. gloriosa sp. nov. (QMB S10269); 15, N. nigritarsus sp. nov. (QMB S111534); 16, N. nebo sp. nov. (QMB S65274); 17, N. excavans Raven, 1984 (QMB S813); 18, N. brisbanensis Raven, 1984 (QMB S767 [male], S111397 [female]); 19, N.gowardae sp. nov.(QMB S774 [male], S111377 [female]); 20, N. salanitri Raven, 1984 (QMB S1166 [male], S111396 [female; with epigastric lobes highlighted*); 21, N. dahmsi Raven, 1984 (QMB S88018 [male tibia I], S800 [male pedipalp], S111481 [female; note bent right spermathecal fundus]). Tibial macrosetae are coloured and labelled according to their relative position (dark blue, prodorsal [pd]; red, prolateral [p] or proventral [pv]; dark grey, ventral [v]; light blue, retroventral [rv]).

FIGURES 55–64. Namea nigritarsus sp. nov., male holotype (QMB S111534) from MountGlorious (south-eastern Queensland), somatic morphology: 55–56, carapace and abdomen, dorsal view; 57, cephalothorax, lateral view; 58, eyes, dorsal view; 59, mouthparts, ventral view; 60–61, cephalothorax and abdomen, ventral view; 62, leg I, prolateral view; 63, leg I tibia, retrolateral view; 64, leg I tibia, profile in standardised prolateral view, showing relative position of macrosetae (p, prolateral; pd, prodorsal; pv, proventral; v, ventral). Scale bars = 3.0 mm.

FIGURES 65–67. Namea nigritarsus sp. nov., male holotype (QMB S111534) from MountGlorious (south-eastern Queensland), pedipalp: 65, retrolateral view; 66, retroventral view; 67, prolateral view. Scale bar = 3.0 mm.

FIGURES 78-80. Namea nebo sp. nov., male holotype (QMB S65274) from Mount Nebo (south-eastern Queensland), pedipalp: 78, retrolateral view; 79, retroventral view; 80, prolateral view. Scale bar = 3.0 mm.

FIGURES 68–77. Namea nebo sp. nov., male holotype (QMB S65274) from Boombana, Mount Nebo (south-eastern Queensland), somatic morphology: 68–69, carapace and abdomen, dorsal view; 70, cephalothorax, lateral view; 71, eyes, dorsal view; 72, mouthparts, ventral view; 73–74, cephalothorax and abdomen, ventral view; 75, leg I, prolateral view; 76, leg I tibia, retrolateral view; 77, leg I tibia, profile in standardised prolateral view, showing relative position of macrosetae (pd, prodorsal; pv, proventral; v, ventral). Scale bars = 3.0 mm.

FIGURES 1–3. The D’Aguilar Range of south-eastern Queensland: 1, elevational heat map showing upland areas surrounding Brisbane, and the relative position of the D’Aguilar Range; 2, topographic map of the D’Aguilar Range (in shaded relief), with major localities highlighted; 3, typical habitat for Namea on rainforest bank at Mount Glorious (Maiala section). Image 3 copyright Queensland Museum (used with permission).