Tylorida ventralis , Dr A. V. Sudhikumar and Mr Nafin K. S. 1877
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 ventralis

description: Tylorida ventralis (Thorell, 1877)
(Figs 1E–F, 2C, 7G–I, 12H–I, 15A–F, 16A–J, 17A–O, 18A–O, 19A–E)
Meta ventralis Thorell, 1877: 423 (Description of male and female)
Argyroepeira ventralis Thorell, 1887: 138. Workman, 1896: 55, plate 55 (Brief somatic description and description of web; illustration of female)
Leucauge ventralis Pocock, 1904: 800, plate 66, fig. 3a–c (Illustration of male and female). Anopas ventralis Archer, 1951: 7, figs 8–9 (Transfer of male and female from Leucauge to Anopas). Tylorida ventralis Chrysanthus, 1975: 31, figs 117–120 (Transfer of male and female from Anopas to Tylorida; illustration of
male and female).
[See World Spider Catalog (2017) for complete list of citations].
Leucauge pondae Tikader, 1970: 44, fig. 25a–d (Description and illustration of male and female); 1982: 89. figs 175–178 (Description and illustration of male and female). Holotype female (Regd. No. 3221/18) and allotype male (Regd. No. 3222/18), both poor in condition, from INDIA: West Sikkim: Bang of Great Rangit river; B. K. Tikader leg.; 20-09-1959; deposited in ZSI, Kolkata, EXAMINED. New Synonymy.
Material examined: INDIA, Kerala: Kottayam, Kumarakom Bird Sanctuary (9o37'46.97''N, 76o25'25.56''E), 13 m alt., 25 February 2013, M. S. Pradeep & M. J. Jobi leg., from web, by hand: 1 male, 2 females, 1 subadult female (ADSH1004514). Alappuzha, Pathiramanal Island (9o37'08.27''N, 76o23'23.86''E), 0 m alt., 13 March 2013, M. S. Pradeep & M. J. Jobi leg., from web, by hand: 9 males, 15 females (ADSH1004515). Kollam, Kulathupuzha (8o54'06.37''N, 77o03'51.70''E), 134 m alt., 29 August 2013 M. S. Pradeep leg., from web, by hand: 5 males, 8 females (ADSH1004516). Kottayam, Pala, Areeppara in Edappady, 9o42'35.62''N, 76o42'48.42''E, 27 m alt., 12 May 2014, M.S. Pradeep leg., from web, by hand: 5 males, 7 females (3 females with egg sac) (ADSH1004517). Kottayam, Kanakappalam in Erumely, 9o27'16.08''N,76o50'43.54''E, 101 m alt., 23 August 2014, M. S. Pradeep leg., from foliage, by hand: 1 female with egg sac (ADSH1004518). Alappuzha, Perumbalam, 9o50'54.13''N, 76o21'39.00''E, 10 m alt., 30 November 2015, M. J. Jobi & Jimmy Paul leg., from web, by hand: 1 male, 1 female, 1 subadult male (ADSH1004519). Ernakulam, Thalacode, 10o03'03.22''N, 76o44'27.12''E, 60 m alt., 25 December 2015, Aswathy leg., from web, by hand: 1 female (ADSH1004520).
Justification of the synonymy. Tikader (1970) described L. pondae based on one female (holotype), three females (paratype) and one male (allotype) collected from the Bank of Great Rangit river, West Sikkim. The description was published in his Spider Fauna of Sikkim and was supported by four text figures- prolateral view of male pedipalp, dorsal view of female habitus, retrolateral view of female opisthosoma and ventral view of epigynum (Tikader 1970: fig. 25a–d). He redescribed the species in 1982 with four text figures – dorsal view of female habitus, dorso-lateral view of left male pedipalp, ventral view of epigynum and female internal genitalia (Tikader 1982: figs 175–178). Later, Sebastian and Peter (2009) provided brief morphological descriptions of both male and female, but presented neither illustrations of the male and female reproductive structures nor information on its possible synonymy with T. ventralis. In the original illustrations of Tikader, the shape of CDBP (Tikader 1970: fig. 25d, Tikader 1982: fig. 176) and the outline of epigynal plate (Tikader 1970: fig. 25c, Tikader 1982: fig. 177) and the female internal genitalia (Tikader 1982: fig. 178) suggest a synonymy of L. pondae with T. ventralis. Detailed examination of the types of L. pondae (Fig. 19A–E) suggests that these specimens have all diagnostic, both somatic and genitalic, features of T. ventralis. The species L. pondae should be regarded as a junior synonym of T. ventralis.
Note. Tylorida ventralis seems to exhibit colour polymorphism, a well-known example of phenotypic diversity, as well as intraspecific variation, both somatic as well as genitalic. We have found two distinct colour morphs of T. ventralis, which show conspicuous variation in female opisthosoma colouration: Silver morph (Figs 1E, 15A, D, 16A, E, F) has silvery abdomen due to silver spots on dorsal and lateral opisthosoma. Yellow morph (Figs 1F, 16J) has dorsal and lateral opisthosoma ornamented with deep yellow spots. In both the morphs, the venter of opisthosoma is generally dull brown with a broad median black patch, cephalothorax is brown, legs are brown with black annulations and posterior extremity of opisthosoma has paired black spots (an identification feature of L. pondae suggested by Tikader). The epigyna of both the morphs are also similar with slight intraspecific variations (compare Fig. 18A–F, J–O with G–I). In the field, Silver morph is commonly encountered than the Yellow morph, which is rare to find. The species is known for its intraspecific variation in genitalia (Jäger & Praxaysombath 2009: figs 24, 28–31, 33, 36–37). Unlike Jäger and Praxaysombath (2009), we have noted both somatic as well as genitalic variations in T. ventralis. Based on the morphology of posterior opisthosoma of females, we have suggested our female specimens to belong to three varieties: variety I, without a ‘caudal tubercle’ (Fig. 16H–J), variety II, with an ‘indistinct caudal tubercle’ (Fig. 15D–F) and variety III, with a ‘distinct caudal tubercle’ (Fig. 16C–E). Tikader (1982) also mentioned similar modification of ‘indistinct caudal tubercle’ of female opisthosoma. The opisthosoma of males, however, in all these three varieties is provided with an ‘indistinct caudal tubercle’ (Figs 15A–C, 16A–B, F–G). It is observed that the variety I females and its males are smaller in size (male body length 4.22–4.62, female body length 5.18–5.43) than that of variety II and variety III females (body length 7.16–7.98) and their corresponding males (body length 6.19–6.27). We have also observed high level of variations in both the male and female genitalia of all the three varieties. The pedipalpi exhibit variations in size, orientation and course of sperm ducts (e.g., Fig. 17A–D, F–I, K–N). The epigyna and internal female genitalia vary significantly from specimen to specimen (e.g., Fig. 18A–O). However, the morphology of male chelicerae (Fig. 17E, J, O) of all the three varieties clearly indicates that these all are intraspecific variants and belonging to the same species, T. ventralis.
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 310-311, DOI: 10.11646/zootaxa.4353.2.3, http://zenodo.org/record/1065166