Mekonglema Zhao & Li, 2020

Zhao, Huifeng, Li, Shuqiang & Zhang, Aibing, 2020, Taxonomic revision of Telemidae (Arachnida, Araneae) from East and Southeast Asia, ZooKeys 933, pp. 15-93 : 15

Genus Mekonglema Zhao & Li gen. nov.

Type species.

Mekonglema bailang sp. nov. from Yunnan, China.

Etymology.

The generic name is a combination of “Mekong” referring to the Mekong-Lancang River which encompasses the distributional range of the genus, and “-lema”, a convention used because it is part of the genus Telema , which was the first genus described in Telemidae . The gender is feminine.

Diagnosis.

Mekonglema gen. nov. resembles Pinelema but can be distinguished by the following: Males of Mekonglema gen. nov. have a bulbal apophysis ( M. bailang sp. nov., M. xinpingi comb. nov., and M. yan sp. nov.) (Fig. 12D ) (vs. absent), or the tip of the embolus is directed dorsally ( M. kaorao sp. nov. and M. walayaku sp. nov.) (Figs 14C, D , 16C, D ) (vs. tip of embolus directed ventrally). Females of Mekonglema gen. nov. can be distinguished from those of Pinelema by the receptacle lacking tubes inside (Fig. 13A ) (vs. receptacle with several membranous tubes inside).

Description.

Total length: 1.06-1.50 (male), 1.15-1.70 (female). Carapace without pattern in troglobitic species or with radial striae in rainforest species, i.e. M. xinpingi comb. nov. Sternum with sparse setae, milky white or light brown in troglobitic species, or nearly black in M. xinpingi comb. nov. Eyes ringed with black, vestigial, or absent; Leg formula: 1-2-4-3, tibial glands belt-shaped (Fig. 1C ). Abdomen of males with three different types of scutae (except in M. yan sp. nov.): the first scuta connects to pedicel, dorsal (arrow 1 on Fig. 12A ); the second scuta is posterior to the first one, dorsal (arrow 2 on Fig. 12A ); and the third scutae are paired, lateral (arrows 3 in Fig. 12A ). Abdomen of females without scuta. Male palp: cymbial apophysis cone shaped and located medially (Fig. 12C ); bulb ellipsoid or nearly ellipsoid, bulbal apophysis present (except M. kaorao sp. nov. and M. walayaku sp. nov.); embolus short relative to cymbium, sclerotized, directed outward from the cymbium in M. bailang sp. nov., M. xinpingi comb. nov., and M. yan sp. nov.; embolus long relative to cymbium, unsclerotized, directed toward cymbium in M. kaorao sp. nov. and M. walayaku sp. nov. Endogyne: composed of single tube-like or globular receptacle with short neck, membranous tubes absent.

Composition.

Mekonglema bailang sp. nov., M. kaorao sp. nov., M. walayaku sp. nov., M. xinpingi comb. nov., and M. yan sp. nov. (Fig. 34 ).

Distribution.

China (Yunnan) and Laos (Luang Prabang) (sites 2-6 in Fig. 33 ).

Figures

Figure 1. Tibial glands on leg III of telemids in East and Southeast Asia (Zhuanlema gen. nov. is not included). A Telema guihua B Pinelema bailongensis C Mekonglema xinpingi comb. nov. D Siamlema changhai sp. nov. E Sundalema anguina comb. nov. F Apneumonella jacobsoni G Telemofila samosirensis.

Figure 12. Mekonglema bailang sp. nov., male holotype A Habitus, dorsal view B embolus, apical view C palp, prolateral view D palp, retrolateral view. Scale bars: 0.2 mm (A), 0.05 mm (B), 0.1 mm (C, D).

Figure 13. Mekonglema bailang sp. nov., female paratype A Endogyne, lateral view B habitus, dorsal view C habitus, ventral view. Scale bars: 0.05 mm (A), 0.2 mm (B, C).

Figure 14. Mekonglema kaorao sp. nov., male holotype A Habitus, dorsal view B embolus, apical view C palp, prolateral view D palp, retrolateral view. Scale bars: 0.2 mm (A), 0.05 mm (B), 0.1 mm (C, D).

Figure 16. Mekonglema walayaku sp. nov., male holotype A Habitus, dorsal view B embolus, apical view C palp, prolateral view D palp, retrolateral view. Scale bars: 0.2 mm (A), 0.05 mm (B), 0.1 mm (C, D).

Figure 33. Distribution records of telemid species in East and Southeast Asia (except Pinelema). 1 Apneumonella jacobsoni 2 Mekonglema bailang sp. nov. 3 M. kaorao sp. nov. 4 M. walayaku sp. nov. 5 M. xinpingi comb. nov. 6 M. yan sp. nov. 7 Siamlema changhai sp. nov. 8 S. suea sp. nov. 9 Sundalema acicularis comb. nov. 10 S. anguina comb. nov. 11 S. bonjol sp. nov. 12 S. khaorakkiat sp. nov. 13 Telema auricoma 14 T. guihua 15 T. nipponica 16 T. wunderlichi 17 Telemofila fabata comb. nov. 18 T. malaysiaensis comb. nov. 19 T. samosirensis 20 Zhuanlema peteri sp. nov.

Figure 34. Maximum likelihood tree of Asian Telemidae. Each genus is indicated by black bar or solid line. BS <70 and PP <95 are not shown, taxa followed by an asterisk indicate the type species of the corresponding genus. BS: bootstrap support; PP: posterior possibility.