Nephila Leach, 1815

Sankaran, Pradeep M., Caleb, John T. D., Joseph, Mathew M. & Sebastian, Pothalil A., 2020, On a new synonymy in the spider genus Nephila Leach, 1815 (Araneidae Nephilinae) from India with supplementary notes on colour polymorphism in the genus, Zootaxa 4786 (4), pp. 592-596 : 592-594

Nephila Leach, 1815

Nephila pilipes (Fabricius, 1793)

Figs 1–3

Aranea longipes Fabricius, 1781: 545 . (For complete list of references, see World Spider Catalog 2020).

Nephila robusta Tikader, 1962: 566 ; Tikader, 1982: 100, figs 191–194. Holotype female from INDIA: West Bengal: North 24 Parganas: Gobardanga (22 o 52’59.62’’N, 88 o 45’49.79’’E), 13 m alt.; B.K. Tikader leg.; 30 September 1956; repository NZC-ZSI, Kolkata (2566/18), examined. New synonymy.

Type material status. The ZSI collection has one glass bottle for this species, labelled as holotype, containing the female specimen in good condition. The same bottle has a small glass vial containing the dissected genitalia.

Additional material examined. INDIA, Kerala: Kollam, Kulathupuzha Forest Reserve (8 o 54’06.37’’N, 77 o 03’51.70’’E), 134 m alt., 31 July 2013, M.S. Pradeep leg., by hand: 1 black morph male, 3 black morph females ( ADSH623218 ) , 4 yellow morph males and 12 yellow morph females ( ADSH623318 ) . Ernakulam, Kothamangalam, Salim Ali Bird Sanctuary ( Thattekkadu Bird Sanctuary ) (10 o 07’48.3’’N, 76 o 41’43.24’’E), 96 m alt., 2 October 2013, M.S. Pradeep leg., by hand: 2 black morph males, 2 black morph females ( ADSH623418 ) , 4 yellow morph males and 9 yellow morph females ( ADSH623518 ) .

Justification of the synonymy. Detailed examination of the holotype of N. robusta revealed that this species has all of the diagnostic features of N. pilipes ( Harvey et al. 2007) : longer than broad opisthosoma with a broad mid-dorsal longitudinal band, very wide and narrow epigynum with paired lateral indentations and deep depression across posterior margin, short and thick copulatory ducts and wide and flat fertilization ducts (compare Fig. 2 A–C with Harvey et al. 2007: figs 4, 28–29). Although the spermathecal bulb of N. robusta looks more spherical in shape, it may be attributed to intraspecific variation and would not warrant the recognition of N. robusta a separate species. The species N. robusta should thus be considered as a junior synonym of N. pilipes .

Note. Nephila pilipes is notable for its colour polymorphism ( Dahl 1912; Tso et al. 2004; Harvey et al. 2007). We also have observed two distinct colour morphs in the Indian population of N. pilipes : black morph with black opisthosoma and reddish legs and yellow morph (typical morph of N. pilipes ) with yellow stripes and spots on opisthosoma and greyish-black legs ( Fig. 1 A–B). In some black morphs, the opisthosoma has an inconspicuous mid-dorsal longitudinal greyish-black patch. The males of both black and yellow morphs are identical in somatic colouration (uniform reddish-brown colouration) except the occurrence of longitudinally arranged silver spots on the opisthosoma of the latter ( Fig. 1 C–D). Except for these variations in somatic colouration, in all other respects, including the morphology of genitalia, the black morph is highly similar to yellow morph (compare Fig. 3 A–D with Fig. 3 E–H).

We were unable to locate the type material of N. dirangensis in the arachnid collection of ZSI, even though the authors claimed that the types were deposited there ( Biswas & Biswas 2006). However, while examining specimens from Uttarakhand deposited in ZSI, we found a few Nephila specimens that are identified as N. dirangensis by one of the original authorities of N. dirangensis (Bijan Biswas) . These specimens in fact belong to Trichonephila clavata (L. Koch, 1878) , indicating that N. dirangensis may be a junior synonym of T. clavata . But confirmation requires examination of type or topotype materials of N. dirangensis . The ZSI collection has a glass jar containing seven female specimens in separate glass tubes labelled as ‘ N. kuhlii ’. These specimens in fact represent the black morph of N. pilipes (compare Fig. 2 E–F with Figs 2 B–C and 3C–D). The species illustrated as ‘ N. kuhlii ’ in Tikader (1982) also is a black morph in its genitalic details (compare Tikader 1982: figs 200–201 with Fig. 3 C–D). All these indicate that the species identified/described from India as ‘ N. kuhlii ’ is indeed a black morph of N. pilipes . Additionally, we also examined the type of Nephila angustata Stoliczka, 1869 (three female specimens; 3552/10) (now a synonym of Leucauge decorata (Blackwall, 1864)) ( Fig. 2 H–I) and all are in a bad condition.

Figures

FIGURE 1A–D. Habitus photographs of Nephila pilipes (Fabricius, 1793). A, C, Black morph (ADSH623218); A, female; C, male. B, D, Yellow morph (typical morph) (ADSH623318); B, female; D, male. Scale bars: C–D, 2 mm. Photo credit A, B Jimmy Paul.

FIGURE 2A–J. Nephila species described from India.A–D Nephila robusta Tikader, 1962:A, Holotype female habitus, dorsal. B, Epigynum of the same, ventral. C, Vulva of the same, dorsal; D, Label from type bottle. E–G, One of the Nephila specimens in the ZSI collection labelled as ‘Nephila kuhlii’ (Doleschall, 1859). E, Epigynum, ventral. F, Vulva, dorsal. G, Label from the jar. H–J, Nephila angustata Stoliczka, 1869; H, female type, dorsal; I, same, prolateral; J, label from type bottle. Scale bars: B–C, H–I, 1 mm; E–F, 0.5 mm. A not to scale.

FIGURE 3A–H. Nephila pilipes (Fabricius, 1793). Genitalia of black (A–D) and yellow morphs (E–H). A, E, Left pedipalp, prolateral. B, F, Same, retrolateral. C, G, Epigynum, ventral. D, H Vulva, dorsal. Abbreviations: C, conductor; CD, copulatory duct; E, embolus; FD, fertilization duct; P, paracymbium; SB, spermathecal bulb; SD, spermduct; ST, subtegulum; T, tegulum. Scale bars: A–H, 0.5 mm.