Tropizodium Jocqué & Churchill, 2005

Dankittipakul, Pakawin, Jocqué, Rudy & Singtripop, Tippawan, 2012, Two new species of the spider genus Tropizodium Jocqué & Churchill, 2005 with notes on the femoral organ clade from Southeast Asia (Araneae, Zodariidae, Zodariinae), Zootaxa 3327, pp. 62-68 : 63-64

Tropizodium Jocqué & Churchill, 2005

Tropizodium Jocqué & Churchill, 2005: 3 .

Indozodion Ovtchinnikov, 2006: 40 , figs 1–4. Syn. nov.

Type species: T. peregrinum Jocqué & Churchill, 2005 , by original designation.

Taxonomic remarks. Representatives of Tropizodium are relatively small spiders (1.5–3.6 mm). Their somatic characters are all very similar, and usually of little diagnostic value at species level. Generally, the prosoma is almost white to pale yellow, often provided with a faint dark brown marking which forms a reticulum on the elevated pars cephalica ( Figs 1–2 ). The anterior margin of the carapace is distinctly narrower in males than in females. The slender legs are pale and devoid of large spines, but covered with numerous flattened incised hairs, especially on the dorsal surface of the femora. The opisthosoma is ovoid, covered with fine, white pubescence on dark sepia background; its lateral sides and venter are pale. In both sexes, an indurated opisthosomal tegument is absent. Although the carapace patterns and opisthosomal color are usually variable between species, these are rarely useful for identification. Consequently, the diagnoses are based almost entirely on the genitalia in both sexes.

Males are diagnosed by the forms of the RTA, the MA and the embolus. There are always small intraspecific variations in the shape of these three palpal components. The RTA is well-developed, greatly extended anteriorly and almost reaching the apex of cymbium ( Fig. 4 ). The lateral surface of the RTA is often provided with modified, serrated setae. The MA is situated on the apico-retrolateral portion of the male bulb ( Fig. 3 ); it is variable in size and shape. The spiniform embolus is almost straight; its base smoothly merges with the bulb ( Fig. 3 ). The cymbium is always provided with one large apical and several pectinated setae.

The shape of the epigyne varies slightly between species, but it is usually sufficiently distinct from those of other species in the same geographical area. The epigyne is very simple, weakly sclerotized, with anterior orifices ( Figs 6–7 ) leading to short and obscure entrance ducts ( Figs 10–12 ) which are further connected to globular spermathecae ( Figs 8–9 )

Other characters, such as eye size and an intercheliceral triangle, are useful confirmatory characters to distinguish Tropizodium from other related genera (see also Jocqué & Churchill 2005). Tropizodium and Zodarion share a combination of the following characters: the cheliceral triangle, the flattened indented hairs and the small femoral organs on legs. Tropizodium can be distinguished by the smaller cheliceral triangle and the eye configuration in which the PME are located closer to the AME. The genus Indozodion resembles that of Tropizodium in having a RTA with its apex extending anteriorly, a slender embolus, an apical spine and modified setae on the cymbium, a weakly sclerotized epigynal region with poorly defined internal ducts, and a pair of subspherical spermathecae. Therefore, it is here considered a junior synonym of Tropizodium .

Included species. T. inayatullahi ( Ovtchinnikov, 2006) comb. nov., T. molokai Jocqué & Churchill, 2005 , T. murphyorum sp. nov., T. peregrinum Jocqué & Churchill, 2005 , T. serraferum ( Lin & Li, 2009) comb. nov., T. siam sp. nov., T. trispinosum ( Suman, 1967) .

Figures

FIGURES 1 – 2. 1 – 2, Tropizodium siam sp. nov., habitus, dorsal. 1, Holotype, male. 2, Paratype, female. Scale lines = 0.5 mm.

FIGURES 3 – 9. 3 – 6, 8, Tropizodium siam. nov. 3 – 5, Holotype, male. 6, 8, Paratype, female. 7, 9, Tropizodium murphyorum sp. nov., holotype, female. 3, Male palp, ventral. 4, Retrolateral. 5, MA, prolateral. 6 – 7, Epigyne, ventral. 8 – 9, Right spermatheca, dorsal. Scale lines: 3 – 5, 8 – 9 = 0.1 mm; 6 – 7 = 0.2 mm.

FIGURES 10 – 12. 10 – 11, Tropizodium siam. nov., paratype, female. 12, Tropizodium murphyorum sp. nov., holotype, female. 10, Epigyne, ventral. 11 – 12, Internal genitalia, dorsal. Scale lines: 10 = 0.1 mm; 11 – 12. = 0.2 mm.