Eutittha submordax ( Zhang, Zhu & Hu, 1993 ) 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 : 1304-1305

Eutittha submordax ( Zhang, Zhu & Hu, 1993) , comb. nov., stat. resurr.

Cheiracanthium virescens (nec Sundevall) Hu 1979, p. 66, fig. 7A–D (♀; misidentification).

Cheiracanthium japonicum (nec Bösenberg & Strand) Hu 1979, p. 66, fig. 8A–D (♂; misidentification). Yin et al. 2012, p. 1050, fig. 546d–f (in part, ♂ only, misidentification).

Cheiracanthium submordax Zhang, Zhu & Hu, 1993, p. 106 , figs 1–4 (description of holotype ♀, allotype ♂ and paratype ♀ from CHINA: Guangxi Province: Ningming County (22.1°N, 107°E); Ch. Zhu leg. VIII.1962). Song et al. 1999, p. 414, figs 242O–P, 244C–D (♂ ♀; reproduced after Zhang et al. 1993); Ono 2009, p. 465, figs 17–20 (♂ ♀); Chen and Huang 2012, p. 22, fig. 6A–F (♂ ♀, synonymy of C. submordax with C. mordax ; here rejected).

Comments

This species was collected in rice fields in Hunan Province, China for the first time. Hu (1979) identified and illustrated collected specimens as two different species, namely the female as Cheiracanthium virescens ( Sundevall, 1833) and the male as Cheiracanthium japonicum Bösenberg & Strand, 1906 . As an explicit new species ( C. submordax ), it was later described from the neighbouring Guangxi Province, China ( Zhang et al. 1993) on the basis of both sexes. Zhang et al. (1993) also pointed out that the females from Hunan are misidentified and in fact belong to E. submordax . Herein, we additionally note that the males from the Hunan Province, in fact, belong to E. submordax as well, as the characteristics of the genus Eutittha are clearly visible in the drawing of the palp ( Hu 1979: fig. 8B– D). Yin et al. (2012) repeated the mistake in the species identification of a male from the Hunan Province. Their drawings of the male’s palp ( Yin et al. 2012: fig. 546d–f) are identical to those of Hu (1979: fig. 8B–D).

The conspecificity of the two species, E. mordax and E. submordax , is not at all certain. Chen and Huang (2012, p. 24) were ‘not able to examine all type specimens of these taxa’, and they ‘compared the descriptions of C. submordax from mainland China and Japan, C. diversum from Tonga and C. mordax from Australia, and materials from Taiwan’. The respective suggestion by Chen and Huang (2012, p. 24) is not reasonable. In the description of Taiwanese specimens, it is indicated that male ‘abdomen yellowish brown, with a grayish brown cardiac pattern dorsally’ ( Chen and Huang 2012, p. 22), while in the Dondale’s redescription of E. mordax , it is indicated that male ‘abdomen off-white, with yellowish heart mark’ ( Dondale 1966, p. 1180). Some differences are found in the drawings of the palp and endogyne of these species. For example, the following is visible in the retrolateral drawings of the male’s palp: cymbium with a slight bulge in E. mordax ( Dondale 1966: fig. 6G), vs. cymbium uniformly rounded in C. submordax Zhang et al. 1993 : fig. 4; Ono 2009: fig. 18); the cymbial fold occupies about half the lateral side of the cymbium in the proximal half in E. mordax ( Dondale 1966: fig. 6G) ( Figure 2 (d)), vs. cymbial fold occupies two-thirds of the lateral side of the cymbium in the proximal half in E. submordax ( Figure 2 (f); Ono 2009: fig. 18). Similarly, in the endogyne drawings – ‘spermathecae constricted near middle’ ( Dondale 1966, p. 1180: fig. 6I, J), in E. mordax , vs. sharply dumbbell-shaped receptacles in C. submordax ( Zhang et al. 1993: fig. 2; Chen and Huang 2012: fig. 6E), but except fig. 20 in Ono (2009). In addition, there is a major disjunction between the areas of the ‘northern’ E. submordax and the ‘southern’ E. mordax and E. brevicalcarata : E. submordax is not known south of 22° N, while E. mordax is not known north of 9° S, and E. brevicalcaratum north of 8° S.

Distribution

China: Guangxi Province ( Zhang et al. 1993), Hunan Province: Xiangyin County (28° 41 ʹ 25 ″ N, 112°54 ʹ 33 ″ E) ( Hu 1979: as Cheiracanthium virescens and Cheiracanthium japonicum ; Yin et al. 2012: as C. japonicum , part). Japan ( Ono 2009). Taiwan: Taoyuan County (24° 59 ʹ 28.6 ″ N, 121°18 ʹ 51.58 ″ E) ( Chen and Huang 2012).

The following species that were once placed in Eutittha , in our opinion, are not representatives of this genus (or for some of them further investigations are necessary) and consequently, still remain in Cheiracanthium .

Eutittha was described as monotypic ( Thorell 1878); however, between 1887 and 1897, Thorell described 10 additional species in this genus. Another species ( E. truncata Thorell, 1895 ) was recognised as valid by Dankittipakul and Beccaloni (2012) based on Thorell (1895) passing and conditional mention of this name in the course of the description of Eutittha gracilipes (for details, see comments on C. truncatum ). Thus, 12 species were once included in this genus. In the following section, we provide an overview of all the remaining species that were once included in Eutittha with comments on their status and the reasons why they are not being re-transferred to Eutittha .

Figures

Figure 2. Epigyne and endogyne of Eutittha mordax (L. Koch, 1866) and E. insulana Thorell, 1878. a. E. mordax epigyne, ventral view. b. E. insulana endogyne, dorsal view. Abbreviations: AR – anterior rim; CD – copulatory duct; S – spermathecae. Scale bar: g 0.1 mm.