Myrmarachne zabkai, 2017

MYRMARACHNE ZABKAI PEKAR View in CoL SP. NOV.

Type material

Australia. NSW: 1♂ holotype ( AMS, KS.92295) (23 November � 9 December 2004; J. Gollan) Upper Hunter River   GoogleMaps , Keys Bridge at Muswellbrook (32 ° 17 0 29 ″ S, 150 ° 50 0 49 ″ E) . QLD: 1♂ paratype ( QMB, S100093 View Materials ) (17 December 2011; I. Macaulay) Mossman (16 ° 27 0 S, 145 ° 22 0 E) . NSW: 1♀ paratype ( AMS, KS.92294) (23 November � 9 December 2004; J. Gollan) Upper Hunter River   GoogleMaps , Keys Bridge at Muswellbrook (32 ° 17 0 29 ″ S, 150 ° 50 0 49 ″ E) .

Material examined

Australia. QLD : 1♂ ( MUB) (22 November 2013; I. Macaulay) Barron Gorge National Park   GoogleMaps , dam (16 ° 51 0 4.34 ″ S, 145 ° 38 0 48.67 ″ E) ; 1♂ ( QMB, S100095 View Materials ) (29 November 2013; I. Macaulay) Marcheeba   GoogleMaps (17 ° 0 0 9.14 ″ S, 145 ° 24 0 40.21 ″ E) ; 1♂ ( QMB, S100094 View Materials ) (27 February 2014; I. Macaulay ) same locality; 1♂ ( MUB) (2 March 2012; I. Macaulay) Cairns   GoogleMaps , Cattana Wetlands near University campus (16 ° 49 0 S, 145 ° 42 0 E) ; 1♀ ( AMS, KS.22138) (28 August 1976; R. E. Mascord) Marcheeba   GoogleMaps (17 ° 00 0 S, 145 ° 26 0 E) ; 1♂ ( QMB, S100143 View Materials ) (11 December 2014; I. Macaulay ) same locality (17 ° 0 0 36.84 ″, 145 ° 25 0 30.09 ″); 1♂ ( AMS, KS.18228) (11 August 1969; N.C. Coleman) Cairns   GoogleMaps (16 ° 55 0 S, 145 ° 46 0 E) ; 1♂ ( AMS, KS.18229) (18 October 1970; N.C. Coleman) Cairns   GoogleMaps , Davis Creek (16 ° 55 0 S, 145 ° 46 0 E) . NSW: 1♀ ( AMS, KS.92289) (23 November 9 December 2004; J. Gollan) Upper Hunter River   GoogleMaps , Keys Bridge at Muswellbrook (32 ° 17 0 29 ″ S, 150 ° 50 0 49 ″ E) ; 1♀ ( AMS, KS.92290) (23 November � 9 December 2004; J. Gollan) Kayuga Bridge   GoogleMaps at Muswellbrook (32 ° 15 0 12 ″ S, 150 ° 53 0 16 ″ E) ; 1♂ ( AMS, KS.92293) (23 November � 9 December 2004; J. Gollan) Keys Bridge   GoogleMaps at Muswellbrook (32 ° 17 0 29 ″ S, 150 ° 50 0 49 ″ E) ; 1♀ ( AMS, KS.92291) (23 November � 9 December 2004; J. Gollan) Jerrys Plains   GoogleMaps (32 ° 31 0 04 ″ S, 150 ° 56 0 22 ″ E) ; 1♀ ( AMS, KS.92292) (23 November � 9 December 2004; J. Gollan) Jerrys Plains   GoogleMaps (32 ° 31 0 05 ″ S, 150 ° 56 0 24 ″ E) ; 1♀ ( AMS, KS.98317) (17 January � 1 February 2006; J. Gollan) Metulla   GoogleMaps at Bureen (32 ° 27 0 07 ″ S, 150 ° 44 0 09 ″ E) ; 1♂ ( QMB, S25340 View Materials ) (1 February 1993; E. Zillman) Bundaberg   GoogleMaps , Baldwins Swamp (24 ° 52 0 0.012 ″ S, 152 ° 21 0 E) .

Etymology

The species name is a patronym in honour of Marek Zabka _, for his kind help with the literature.

Diagnosis

This species is related to M. bicolor . Males can be distinguished by the apophyses on fangs, longer teeth on chelicera, and tiny RTA. Females can be distinguished by the kidney-shaped atria of the epigyne.

Description

Male: Measurements (N = 4): total body length 5.5 mm (5.3 – 5.6 mm), carapace length 2.0 mm (1.9 – 2.1 mm), carapace width 1.2 mm (1.1 – 1.2 mm), chelicera length 1.5 mm (1.4 – 1.7 mm), abdomen length 1.9 mm (1.7 – 2.1 mm), PTB = 0.43. Colour ( Fig. S1S View Figure 1 ): chelicerae reticulated with metallic shine; clypeus with white hairs; carapace orange to brown, sparsely covered with white hairs; cephalic part dorsally dark brown to black, with black patches around eyes; sternum and endites light brown, palpal segments brown; leg segments yellow to brown, but Cx I and II, Pt I and II, Ti I and II, and Ta I – IV with black stripes on sides; abdomen dorsally dark brown with a white stripe on lateral sides in the constriction, ventrally light brown. Morphology: chelicerae protruding, dorsally flat, with five strong retromarginal teeth and four smaller teeth, decreasing in size ( Fig. 4E, F View Figure 4 ); fangs sinuous with a single ventral strong apophysis and two tiny ones, curved tips ( Fig. 14F View Figure 14 ); prosoma elongate ( Fig. 14A, B View Figure 14 ), carapace with a shallow constriction behind PLE ( Fig. 14B View Figure 14 ), cephalic part of carapace higher than thoracic part; leg spines: Ti I with five ventral pairs, Mt I and II, Ti II with two ventral pairs; abdomen elongate with a constriction and two dorsal scuta ( Fig. 14D View Figure 14 ); palpal cymbium oval, tegulum large and round, embolus long, slen- der, straight at tip, coiled almost twice ( Figs 2M, 14G View Figure 14 ); RTA narrow, sinusoid, flange not developed ( Figs 2N, 14H View Figure 14 ).

Female: Measurements (N = 2): total body length 5.2 mm (5.0 – 5.4 mm), carapace length 2.2 mm (2.1 – 2.2 mm), carapace width 1.1 mm, chelicera length 0.5 mm, abdomen length 2.4 mm (2.1 – 2.6 mm). Colour: as in males. Morphology: as in males, but chelicera small, cephalic part as high as thoracic part ( Fig. 14C, D View Figure 14 ); epigyne with atria kidney shaped, separated by a septum, atria 1.2 times wider than septum ( Fig. 14I View Figure 14 ); median pocket below septum; spermathecae elongate, copulatory ducts massively twisted above atria ( Fig. 14J View Figure 14 ).

Natural history

This species seems to imitate the ant Opisthopsis haddoni Emery, 1893 .

Distribution

Australia: QLD, NSW ( Fig. 4J View Figure 4 ).

PHYLOGENETIC ANALYSIS

The 16S rRNA – tRNA Leu( CUN) –NAD1 gene fragment (633 bp) was successfully amplified in 45 individuals, whereas the COI fragment (471 bp) was amplified in just 32 individuals. Amplification of that fragment was not successful for the whole macleayana group, and partly also for M. milledgei sp. nov., M. bicolor , and the luctuosa group. The obtained sequences are available in the GenBank database ( Table 2).

Bayesian analysis resulted in five main clades, all which were very well supported ( Fig. 15 View Figure 15 ). Myrmarachne erythrocephala , M. luctuosa , and M. striatipes are sister species, together forming a monophyletic group, distantly related to the rest. Myrmarachne bicolor is closely related to M. macleayana . Myrmarachne milledgei sp. nov. can be placed in the macleayana clade, but its position was assessed based on a single individual and on the 16S rRNA – tRNA Leu( CUN) –NAD1 gene fragment alone. Myrmarachne helensmithae sp. nov. and M. macaulayi sp. nov. are closely related species, differing at most by a single nucleotide in the case of both sequenced gene fragments. Myrmarachne smaragdina was placed in the same clade as M. macaulayi sp. nov.; however, it has relatively high within-species divergence. Although they came from the same site, the two individuals of M. smaragdina differed by 2.3% in COI and 2.8% in the 16S rRNA – tRNA Leu( CUN) –NAD1 fragment.

Within-group and within-species mean differences (p – distances) show clear delimitation of the species, with the exception of several inconsistencies in the luctuosa / striatipes clade ( Table 3). Myrmarachne luctuosa f. aurea collected at a Townsville site differed distinctly from M. luctuosa f. aurea collected at Brisbane and Scarness sites, although both gene fragments were amplified successfully in their whole lengths. In the COI gene these samples differed by 4.67%, and even by 5.5% in the 16S rRNA – tRNA Leu ( CUN) –NAD1 fragment. On the other hand, M. luctuosa f. aurea from Brisbane was very similar to M. luctuosa f. aeneopilosa from Sydney. Myrmarachne luctuosa f. aurea from Scarness was very similar to M. luctuosa f. aeneopilosa from Port Macquarie (both differing by just three bases within the concatenated fragments). Among the striatipes individuals (f. urens from Tasmania and f. striatipes from Wyrrabalong) only the 16S rRNA – tRNA Leu ( CUN) –NAD1 gene was involved in the final data set. Myrmarachne striatipes f. striatipes differed from f. urens by 4.4%. Differences among the forms of Myrmarachne erythrocephala could not be revealed using the two molecular markers.

Haplotype networks ( Fig. 16 View Figure 16 ) show the detailed relationships among the taxa studied, in terms of the exact number of mutation steps. All specimens of three forms of M. erythrocephala differ in less than five mutations in both genes. Similarly, specimens of two forms of M. macleayana differ in just two mutations. But specimens of M. luctuosa and M. striatipes show quite a large variation in the number of mutations, particularly in the 16S rRNA – tRNA Leu( CUN) – NAD1 gene. And there is a big difference among M. smaragdina specimens also.