Tylorida marmorea Sankaran & Malamel & Joseph & Sebastian 2017, comb. nov.
Creators: name: Sankaran, Pradeep M.
name: Malamel, Jobi J.
name: Joseph, Mathew M.
name: Sebastian, Pothalil A.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Tetragnathidae
Tylorida
Tylorida marmorea

description: Tylorida marmorea (Pocock, 1901) comb. nov.
(Figs 1B–C, 2A, 5A–F, 6A–D, 7A–C, 8A–H, 9A–D, 10A–I, 11A–F, 12A–E)
Orsinome marmorea Pocock, 1901: 479 (Brief description of male and female [Holotype not designated; unspecified number of specimens collected from INDIA: Tamil Nadu: Ootacamund (now known as Udhagamandalam or Ooty); G. F. Hampson leg., Kerala: Trivandrum: Ponmudi; H. Ferguson leg.; specimen repository unknown, possibly BMNH or ZSI]) NOT EXAMINED. Sherriffs, 1918: 31 (Brief description of the natural history of the species; mentioned body size of male and female); 1919: 232 (Brief description of the natural history of the species; mentioned body size of male and female). Gravely, 1915: 537 (Brief description of the natural history of the species); 1921: 448, fig. 7a–b (Brief description of male & female; illustration of chelicerae of male & female).
Leucauge cylindrata Wang, 1991: 158, figs 21–24 (Description and illustration of male and female [Holotype not assigned; male and female specimens from CHINA: Yue Ning County: Hunan Province; Wang Jia-Fu & Zhang Yong-Jing leg.; 7- 08-1984; repository unknown) NOT EXAMINED. Song, Zhu & Chen, 1999: 216, figs 121G, 122C–D, 130K (Illustration of male and female).
Tylorida cylindrata Zhu, Wu & Song, 2002: 26, fig. 1A–H (Transfer of male and female to Tylorida; description and illustration of male and female). Zhu, Song & Zhang, 2003: 300, fig. 167A–H (Description and illustration of male and female). Yin et al., 2012: 469, fig. 214a–e (Illustration of male and female). New synonymy.
Tylorida sataraensis Kulkarni, 2014: 5558, images 1–5, figs 2–4 (Description, images and illustration of female [Holotype female (ZSI-WRC-Ar/439) from INDIA: Maharashtra: Chalkewadi; S. Kulkarni leg.; 6-03-2013, paratypes 4 females (Regd. No. ZSI-WRC-Ar/440) same data as for holotype except S. Kulkarni & A. Sargar leg.; 12-01-2012; holotype and paratypes are deposited in ZSI-WRC) NOT EXAMINED. Kulkarni & Lewis, 2015: 2, images 1b, 2b, 3b, 4, 5b, 6–7, 9–11 (Description and images of male; images of female; provided comparison of male with male of T. ventralis). New Synonymy.
Material examined. INDIA: Kerala: Malappuram, Akambadam, 11o18'37.42''N, 76o12'31.68''E, 41 m alt., 15 May 2013, Pradeep M. S. leg., from web, by hand: 1 male, 2 females (ADSH 100457). Trivandrum, Kallar in Ponmudi, 8o45'35.79''N, 77o07'00.75''E, 920 m alt., 0 1 October 2014, M.S. Pradeep leg., from web, by hand: 2 males, 4 females (ADSH 100458). Idukki, Vagamon, 9o41’10.25’’N, 76o54’18.83’’E, 1013 m alt. 15 July 2015, Jimmy Paul leg., from web, by hand: 1 male (ADSH 100459). Idukki, Munnar, Eravikulam National Park, foothills of Anamudi, 10o09’18.40’’N, 77o04’07.49’’E, 1885 m alt., 2 November 2016, Jimmy Paul leg., from web, by hand: 1 female, 2 subadult males (ADSH1004510).
Diagnosis. Tylorida marmorea comb. nov. is most similar to T. ventralis, but can be separated from the latter by the following combination of characters: Males: I & II tibiae, metatarsi and tarsi provided ventrally with short, cone-like macrosetae (I & II tibiae, metatarsi and tarsi of T. ventralis lack such macrosetae), cheliceral retromargin basally with a large, slightly bifid tubercle (in T. ventralis, cheliceral retromargin basally with a large, bluntly rounded tubercle), short cymbial dorso-basal process (T. ventralis with long cymbial dorso-basal process), comparatively long embolus (embolus tiny in T. ventralis) and conductor extends up to embolic base (conductor in T. ventralis extends up to the basal half of embolus). Females: epigynal plate with prominent postero-median lobe lacking lateral and median lobes (postero-median lobe of epigynal plate in T. ventralis less prominent with well marked lateral and median lobes), copulatory ducts with short distal half (copulatory ducts in T. ventralis with long distal half), bulky spermathecal bulb (T. ventralis with compact spermathecal bulb) and fertilization ducts with contiguous distal parts (fertilization ducts in T. ventralis widely separated along the entire length) (compare Figs 7A–C, 10A–H, 11A–F, 12A, C, E–b with Figs 7G–I, 12H, 17A–O, 18A–O, Jäger & Praxaysombath 2009: fig. 25, Yin et al. 2012: fig. 216b–f).
Redescription. Male (ADSH 100457, Figs 6A–B, 7A–C, 12C): Prosoma brown with a median faint yellowish band. Eyefield brown; lateral eyes contiguous, situated on a shallow tubercle. Clypeus, chelicerae, fangs, labium, maxillae, sternum brown. Sternum rebordered marginally. Cheliceral promargin with three teeth, distal one is placed far away from the rest; retromargin with four teeth and a large, slightly bifid basal tubercle (Fig. 12C). Opisthosoma elongated oval, greyish; dorsum provided with a median longitudinal black band flanked on both sides by few silvery spots and irregular black bands; laterals mottled with longitudinal black bands; venter with a broad median longitudinal black patch flanked on both sides by numerous longitudinally placed silver spots. Spinnerets greyish-black. Leg segments yellowish-brown with broad brown annulations; all leg segments except patellae rebordered; I & II tibiae, metatarsi and tarsi provided ventrally with short, cone-like macrosetae (Fig. 7A– C); femur III prolaterally with a single row of trichobothriae (6 in number); femur IV prolaterally with single row of trichobothriae (8 in number). Body length 9.40. Prosoma length 4.08, width 3.01, height 1.18. Opisthosoma length 5.32, width 2.95, height 2.74. Eye diameter: ALE 0.21. AME 0.28. PLE 0.18. PME 0.19. Eye interdistance: AME–ALE 0.13. AME–AME 0.13. AME–PME 0.17. PME–PLE 0.25. PME–PME 0.18. Clypeus height at ALE 0.36, at AME 0.28. Length of chelicerae 2.32. Length of trochanter of pedipalp 1.34. Measurements of pedipalp and legs: Pedipalp 5.45 [2.36, 0.53, 0.62, 1.94], I 31.61 [8.47, 1.85, 8.32, 10.67, 2.30], II 22.61 [6.34, 1.60, 5.50, 7.30, 1.87], III 10.48 [3.45, 0.98, 2.13, 2.84, 1.08], IV 17.58 [5.56, 1.15, 4.09, 5.46, 1.32]. Leg formula: 1243. Spination. Pedipalp. 0 0 0 0, 0 0 0 0, 0 0 0 0, 0000; legs: femur I 7350, II 5240, III 2 320, IV 3520; patellae I–IV 0200; tibia I 3240, II 3230, III 2110, IV 2220; metatarsus I 1110, II 0 210, III 2100, IV 3110; tarsi I–IV 0 0 0 0. Pedipalp (Figs 8E–H, 10E–I): Pedipalp segments yellowish-brown. Tegulum brown, large, nearly globular, with a short, disto-median triangular process lying parallel to the distal part of the embolic base (Figs 8F–G, 10F–G, I). Subtegulum dark brown. Embolus short, spine-like, distally with a slight retrolateral bend (Figs 8F, 10F). Embolic base thick, apically flat, with apical twist (Figs 8F, 10F). Conductor broad, flat, lying dorsally in close contact with the median part of embolic base (Figs 8E, G–H, 10E, G–I). Cymbial dorso-basal process short, flat, slightly folded retrolaterally and terminally (Figs 8H, 10E, H). Paracymbium short, broad, dorso-ventrally flattened, with weakly sclerotized prolateral half, with apical warp (Figs 8E, G–H, 10E, G–H).
Female (ADSH 100457, Figs 6C–D, 12D): In all details like male except the following: Sternum not rebordered. Cheliceral promargin with three nearly equal sized teeth; retromargin with four teeth, slightly smaller than the promarginal ones; 4th retromarginal tooth smallest (Fig. 12D). Spinnerets black. Leg segments yellowishbrown to brown progressively without ventral cone-like macrosetae; femur III prolaterally with a single row of trichobothriae (8 in number); femur IV prolaterally with single row of trichobothriae (11 in number). Palp segments yellowish-brown to brown towards distally. Body length 11.47. Prosoma length 4.92, width 3.92, height 1.98. Opisthosoma length 6.55, width 3.40, height 3.03. Eye diameter: ALE 0.28. AME 0.31. PLE 0.22. PME 0.23. Eye interdistance: AME–ALE 0.13. AME–AME 0.12. AME–PME 0.19. PME–PLE 0.34. PME–PME 0.22. Clypeus height at ALE 0.38, at AME 0.34. Length of chelicerae 2.62. Measurements of palp and legs: Palp 5.31 [1.66, 0.68, 1.00, 1.97], I 40.59 [11.34, 2.53, 10.34, 13.57, 2.81], II 28.51 [8.26, 2.13, 6.71, 9.07, 2.34], III 14.21 [4.73, 1.34, 2.88, 3.88, 1.38], IV 23.96 [7.85, 1.61, 5.56, 7.13, 1.81]. Leg formula: 1243. Spination. Palp. 0 0 0 0, 1000, 1100, 3216; legs: femur I 6250, II 4250, III 3320, IV 3520; patellae I–IV 0200; tibia I 4230, II 3230, III 2110, IV 2120; metatarsus I 1110, II 1110, III 2100, IV 3110; tarsi I–IV 0 0 0 0. Epigynum (Figs 9C–D, 11C–D, F): Epigynum flat with circular epigynal plate, constricted postero-laterally to form a postero-median lobe without forming lateral and median lobes, postero-median lobe baso-laterally provided with hook-like sclerotized processes (Figs 9C, 11C). Copulatory openings hardly visible ventrally. Fertilization ducts membranous, basally with a sharp twist, proximal half widely separated, distal half contiguous, originating baso-retrolateral part of spermathecal bulb (Fig. 11D, F). Copulatory ducts heavily sclerotized, basal half highly wrinkled giving the appearance of fused spiracles, distal half smooth occupying proximal 2/3rd of epigynal plate (Fig. 11D, F). Spermathecal bulb very long, diverging, inflated balloon-like (Figs 9D, 11D).
Justification of the transfer of O. marmorea to Tylorida. Pocock (1901) described O. marmorea based on specimens collected from Ooty of Tamil Nadu State and Ponmudi of Kerala State of southern India. The species was redescribed by Gravely (1921), who illustrated the male and female chelicerae of the species, which are diagnosable (Gravely 1921: fig. 7a–b; herein Fig. 12E). The illustrations of Gravely match exactly with the male and female chelicerae of the specimens collected from Ponmudi, indicating that these two belong to the same species, O. marmorea (compare Fig. 12A–B with Gravely 1921: fig. 7a–b). However, further examination of the male and female genitalia of the specimens from Ponmudi revealed that these specimens do not belong to the genus Orsinome, but to the genus Tylorida: proximally placed cymbial dorso-basal process, bulb with disto-median process of tegulum, embolus with short, tubular distal half, apico-retrolaterally placed embolic base, larger tegulum, epigynum with broad sclerotized plate having posterior extension, copulatory openings lie proximal to the epigynal plate and female internal genitalia with long, tubular fertilization ducts (compare Figs 8A–D, 9A–B, 10A– D, 11A–B, E with 21A–G). Based on these observations we consider the transfer of O. marmorea to Tylorida fully justified.
Justification of the synonymy of T. cylindrata with T. marmorea comb. nov .. Wang (1991) described T. cylindrata from the Hunan Province of China based on 17 female and seven male specimens. The species was later redescribed by Song, Zhu & Chen (1999), Zhu, Wu & Song (2002), Zhu, Song, Zhang (2003) and Yin et al. (2012). The illustrations of pedipalp, epigynum and female internal genitalia of this species match exactly with the genitalic features of T. marmorea comb. nov. including size and shape of paracymbium, cymbial dorso-basal process, tegulum, subtegulum, embolus, embolic base, epigynal plate and copulatory ducts, course of sperm duct, shape and length of conductor and shape and orientation of fertilization ducts (compare Figs 8A–H, 10A–H, 11A– F with Wang 1991: figs 22–23; Song, Zhu & Chen 1999: fig. 1C–D, G–H). The male chelicerae illustrated for this species are similar with the male chelicerae of T. marmorea comb. nov. as both possess three promarginal and four retromarginal teeth and one retromarginal tubercle (compare Fig. 12A, C with Song, Zhu & Chen 1999: fig. 1E–F). The shape of the retromarginal tubercle in T. cylindrata varies slightly from the shape of the retromarginal tubercle of T. marmorea comb. nov., which is possibly due to errors in illustration. Unlike T. marmorea comb. nov., the female opisthosoma of T. cylindrata is provided with a caudal tubercle and the epigynal plate has slight mid-lateral protrutions, but all these may attribute to intraspecific variations, which is a common phenomenon in the genus (see below). Based on these observations, we consider the decision to regard T. cylindrata as a junior synonym of T. marmorea comb. nov. fully justified.
Justification of the synonymy of T. sataraensis with T. marmorea comb. nov .. Kulkarni (2014) described T. sataraensis based on female specimens collected from the rocky outcrop of Chalkewadi in Maharashtra of northern India. Its male sex was described by Kulkarni and Lewis in 2015. Although we did not examine the type of T. sataraensis, the images of genitalia of this species are available in the literature to facilitate its identification (Kulkarni 2014; Kulkarni & Lewis 2015). Detailed comparison of the pedipalp and epigynum of T. marmorea comb. nov. with the images of the genitalia of T. sataraensis shows that T. sataraensis is similar in all aspects with T. marmorea comb. nov. including the shape and orientation of conductor and embolus, the shape of the paracymbium and the cymbial dorso-basal process, shape of epigynal plate, shape of spermathecae and copulatory ducts (compare Figs 8A–H, 9A–D, 10A–H, 11A–F with Kulkarni 2014: images 4–5; Kulkarni & Lewis 2015: figs 1b, 2b, 3b, 4, 5b). Though the pedipalp and epigynum of T. marmorea comb. nov. differ slightly from that of T. sataraensis in its size, size and orientation of distal part of embolus, position and orientation of disto-median process of tegulum, number and nature of course of loops of sperm duct and shape of epigynal plate, these differences, which we consider as intraspecific variation (see below), are little and less evident to separate it as a different species. The species T. sataraensis should thus be considered as a junior synonym of T. marmorea comb. nov..
Biology and natural history. Tylorida marmorea comb. nov. builds its large orb-webs above the course of the streams or water-logging areas (Gravely 1915, 1921; Kulkarni 2014; present data). The webs are constructed horizontally to the water body (Gravely 1915; present data). This species is notable for its colonial aggregation (Gravely 1915; present data). Members of the species were found to occur in colonies of 6-10 members. Each colony consisted of several webs (Gravely 1915; present data), the number of which depends upon the number of individual members of the colony (Sankaran pers. obs.). Adult and subadult individuals of both sexes were found to occur in the same colony. It is not confirmed whether this species is exclusively a colonial or solitary one, which needs further investigation. The species is also remarkable for its ‘dive and thrive’ behaviour to escape from danger (Gravely 1915, 1921; Kulkarni 2014; Kulkarni & Lewis 2015; present data), which may correlate with the selection of sites (above streams and water-logging areas) for web construction.
Intraspecific variation. Tylorida marmorea comb. nov. is found to live in both low and high altitude habitats (41–1885 m alt.) (Gravely 1915, 1921; Kulkarni 2014; Kulkarni & Lewis 2015; present data). We have collected this species from both low (41 m alt.) and high altitude (920–1885 m alt.) habitats. Specimens collected from high altitude habitats (from Ponmudi, Vagamon and Anamudi foothills) were found to be larger in size (male body length 12.67–13.8, female body length 14.14–16.25) than the specimens located at low altitude habitats (from Akambadam) (male body length 9.40, female body length 10.18–11.47) (Figs 5A–F, 6A–D). Specimens from high altitude habitats were larger in body size and darker in body colouration than those from low altitude habitats, which were smaller in body size and lighter in body colouration (Figs 5A–F, 6A–D). The male and female genitalia of specimens from both high and low altitudes show slight variations in size, course of sperm duct, shape and orientation of embolus, size and position of disto-median triangular process of tegulum, shape of epigynal plate, copulatory duct, spermathecal bulb and orientation of fertilization duct (Figs 10A–H, 11A–F). However, the male chelicerae of both high and low altitude specimens (Fig. 12A, C) are the same indicating that all the above mentioned variations are mere intraspecific and infact both belong to the same species. It is notable that specimens from high altitude habitats have relatively large pedipalp and epigynum compared to that from the low altitude habitats (Figs 8A–H, 9A–D).
description: Published as part of Sankaran, Pradeep M., Malamel, Jobi J., Joseph, Mathew M. & Sebastian, Pothalil A., 2017, On the genus Tylorida Simon, 1894 with the first record of the genus Atelidea Simon, 1895 from India (Araneae: Tetragnathidae, Leucauginae), pp. 294-326 in Zootaxa 4353 (2) on pages 297-306, DOI: 10.11646/zootaxa.4353.2.3, http://zenodo.org/record/1065166