Eutittha mordax (L. Koch, 1866 ) Esyunin & Zamani, 2020

Esyunin, Sergei L. & Zamani, Alireza, 2020, ‘ Conundrum of esoterica’: on the long-forgotten genus Eutittha Thorell, 1878, with new taxonomic considerations in Cheiracanthium C. L. Koch, 1839 (Araneae: Cheiracanthiidae), Journal of Natural History (J. Nat. Hist.) 54 (19 - 20), pp. 1293-1323 : 1302-1303

Eutittha mordax (L. Koch, 1866) , comb. nov.

Cheiracanthium mordax L. Koch, 1866, p. 262 , pl. 11, fig. 167 (description of type ♂ from SAMOA: Upolu Island (13°55’S, 171°45 ʹ W )); L. Koch 1873: 403, pl. 31, fig. 5 (♂); Main 1964: 76, figs A–F (♂); Dondale 1966, p. 1178, fig. 6 F–J (♂, S ♀); Dierkens and Ramage 2016, p. 140, figs 12–14 (♂ ♀).

Cheiracanthium diversum L. Koch, 1873, p. 396 , pl. 32, fig. 2 (description of holotype ♂ from SAMOA: Upolu Island (13°55’S, 171°45 ʹ W )) . Marples 1959, p. 364, fig 1 (♀).

Cheiracanthium gilvum L. Koch, 1873, p. 410 , pl. 32, figs 5–6 (description of syntype 1 ♂ from AUSTRALIA: Queensland: Bowen (20°01’S, 148°14 ʹ E) and syntypes 2 ♂ and 4 ♀ from SAMOA: Upolu Island (13°55’S, 171°45 ʹ W )) .

Comments

Eutittha mordax is considered as widespread in Australia and Polynesia ( Main 1964; Dondale 1966). However, at present, the taxonomic status of this species is unclear, and the grouping of mordax - species group has to be regarded as preliminary until the species status of E. mordax is resolved.

For one thing, the type specimen of E. mordax is apparently lost ( Dondale 1966). Dondale (1966) examined the males determined by Koch (1873) and type specimens of two other Koch’s species, namely C. diversum and C. gilvum , which he considered synonymous with E. mordax . Thus, Dondale was the first to consider species from mordax group as one widespread species. Chen and Huang (2012), who considered Cheiracanthium submordax Zhang, Zhu & Hu, 1993 from East Asia to be a junior synonym of E. mordax , have the same broad interpretation of the species. Dierkens and Ramage (2016), who examined a small series of spiders from Polynesia, are more cautious in their statements. They identified their specimens as E. mordax by comparing the drawings of various authors. However, they noted that their specimens are very similar to E. brevicalcarata . Moreover, they suggested that E. brevicalcarata is a junior synonym of E. mordax ( Dierkens & Ramage 2016, p. 141: ‘ Cheiracanthium mordax L. Koch dans le Pacifique, espéce probablement synonyme de Ch. brevicalcaratum L. Koch’.). According to this view, E. mordax is ‘a single, somewhat variable species’ ( Dondale 1966, p. 1180).

On the other hand, Marples (1959) examined a series of three males and one female collected in Tonga and he identified these specimens as C. diversum and described the female for the first time. His description and drawing of the epigyne are significantly different from those of Dondale (characteristics after Dondale (1966) in parenthesis): carapace length 3.60 (2.8–3.0), carapace width 2.40 (2.3–2.6), ratio carapace length/ width 1.5 (1.2), chelicerae ‘large and projecting forwards’ (‘relatively short and stout’), leg I spination ‘one pair at the proximal end of the tibia’ (‘femur I and tibia I armature reduced to 1 or 0 spiniforms’), copulatory ducts twisted thrice around the spermathecae (copulatory ducts twisted twice around the spermathecae) ( Marples 1959, p. 364, fig 1; Dondale 1966, p. 1180, fig. 6I, J). The latter characteristic is especially important since Dondale noted that ‘there is apparent variation, for example,... in the degree of constriction of the epigynal median plate, but... spermathecae appear stable’ ( Dondale 1966, p. 1180). We also agree with Dierkens and Ramage (2016, p. 82) that the palp of male from French Polynesia is different from that of E. mordax illustrated by Dondale (1966). It seems that a broad interpretation of E. mordax is not always justified and, in particular, we cannot agree with the opinion of Chen and Huang (2012, p. 22) on the identity of Cheiracanthium submordax Zhang, Zhu & Hu, 1993 and E. mordax (for details, see the comments on E. submordax ).

Distribution

Samoa ( Koch 1866, 1873), Fiji ( Koch 1873), Australia: Queensland ( Koch 1873), capital territory ( Dondale 1966) (see also ALA 2020).

Doubtful records: Tonga (21°12 ʹ 41 ″ S, 175°09 ʹ 11 ″ E) ( Marples 1959) . French Polynesia: Raiatea Island (16°46 ʹ 46.98 ″ S, 151°27 ʹ 36.18 ″ E), Tahiti Island (17°32 ʹ 8.26 ″ S, 149°31 ʹ 6.74 ″ E), Marquesas Island (9°27’S, 139°23 ʹ E) ( Dierkens and Ramage 2016) .