Taxonomic Account of the Genus Nephila (Araneae: Nephilidae) of Bangladesh

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WSN 123 (2019) 66-75 EISSN 2392-2192

V. Biswas1,a and D. Raychaudhuri2,b 1Department of Zoology, Khulna Govt. Womens’ College, Khulna - 9000, Bangladesh 2Department of Agricultural Biotechnology, IRDM Faculty Centre Ramakrishna Mission Vivekananda University, Narendrapur Kolkata - 700103, West Bengal, India a,bE-mail address: vivekarach @gmail.com , [email protected]

ABSTRACT Spider genus Nephila Leach was so far unknown from Bangladesh. With the record of N. nandiniae n. sp. and N. pilipes (Fabricius), Nephila of Bangladesh is now known by two (2) species. A key to the species together with the generic diagnosis, illustrated description and distribution of both the species are provided.

Keywords: New species, new record, Nephila, Araneae, Nephilidae, Bangladesh

1. INTRODUCTION

Nephilidae, is a common, diverse, orb-weaving spider family, distributed all over the world. Members of this family are poorly known from Bangladesh (Chowdhury & Nagari, 1981; Biswas et al., 1993; Okuma et al., 1993; Biswas, 1995; Begum & Biswas, 1997; Biswas & Raychaudhuri, 2012). But a good number of works are done elsewhere like - India ( Pocock, 1900; Tikader, 1970, ‘82; Tikader & Biswas, 1981; Biswas & Biswas, 1992 ), Pakistan (Dyal, 1935), Myanmar (Thorell, 1895), China (Chen & Zhang, 1991; Zhu et al., 2003; Song et al.,

( Received 10 February 2019; Accepted 02 March 2019; Date of Publication 03 March 2019 ) World Scientific News 123 (2019) 66-75

1999; Zhao, 1993), The Philippines (Barrion & Litsinger, 1995), Japan (Yaginuma, 1986), USA (Robinson & Robinson, 1973). Genus Nephila Leach, usually known as ‘giant wood spider’, is well distributed throughout the world. It spins typical, large geometric webs between the trees. The genus was first erected by Leach in 1815 with the type-species Aranea maculata. Till date, the genus is known by 38 species all over the world (WSC, 2019) but were so far unknown from Bangladesh. With the present record, the genus in Bangladesh, is now known by only two (2) species of which N. nandiniae is identified as new to science while N. pilipes (Fabricius) is hitherto new record for the country. A key to species together with their illustrated descriptions, generic diagnosis and distribution are presented herewith.

2. MATERIALS AND METHODS

The work was carried out with the collection of specimens from the webs made by the spiders in the gardens of Chitalmari, Bagerhat, Bangladesh. Collection and preservation of the samples were done following Kaston (1972) and Tikader (1987). The spider samples thus collected were studied under Stereo Zoom Binocular Microscope (model- SV 8, Zeiss). All the measurements are in millimeters (mm).

Abbreviations ALE = anterior lateral eyes; AME = anterior median eyes; PLE = posterior lateral eyes; PME = posterior median eyes; AL = abdominal length; CL = carapace length; TL = total length; AW = abdominal width; CH = carapace height; CW = carapace width; KGWCMZ = Khulna Govt. Womens’ College, Museum of Zoology; ZSI = Zoological Survey of India. The identified specimens were later confirmed from the Zoological Survey of India, Kolkata. The types are now in the deposition of Khulna Govt. Womens’ College.

3. TAXONOMY

Family: Nephilidae Simon, 1894 Genus: Nephila Leach, 1815 1985. Nephila Leach, Zoological Miscellany: 133.

Diagnosis: Cephalothorax with cephalic region convex, more elevated than the thoracic region and usually armed posteriorly with one pair of tubercles. Eyes small, more or less similar; anterome - dians widely separate, anterolaterals close or nearly so. Ocular quad nearly square. Chelicerae long, strong and robust, with strong teeth. Maxillae and labium usually longer than wide, both scopulate anteriorly. Sternum broad, heart-shaped or nearly so, pointed behind. Legs very long and strong, spinulose; tarsi and metatarsi together longer than tibia plus patella. Abdomen very long, broad; epigyne strongly sclerotized with distinct lateral openings.

Type - species: Aranea pilipes Fabricius, 1793.

Distribution: America; Asia; Australia and Europe.

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Key to the species 1. Cephalic region strongly constricted; lateral eyes never placed marginally; abdominal dorsum never wrinkled; cheliceral fang segmented; outer margin of chelicerae with 4 teeth; epigyne and internal genitalia as in Figs. 5 & 6 ……………………. pilipes

Cephalic region weakly constricted; lateral eyes placed marginally; abdominal dorsum wrinkled; cheliceral fang not segmented; outer margin of chelicerae with 2 teeth; epigyne and internal genitalia as in Figs. 13 & 14 …….……. nandiniae n. sp.

1. Nephila pilipes (Fabricius) (Figs. 1-7; Plate - I,a )

1793. Aranea pilipes Fabricius, Ent. Syst., 2: 425 1900. Nephila maculata Pocock, Fauna Brit. India, Arachn.: 217. 1982. Nephila maculata Tikader, Fauna of India, Araneae, 2(1): 97. 2019. Nephila pilipes World Spider Catalog. Version 20.0, Natural History Museum, Bern, http://www.wsc.nmbe.ch

Material examined: 4♀♀, 1♂, Bagerhat, Khulna, Bangladesh, 12. VII. 1993, Coll. V. Biswas; 1 ♀, Pirojpur, Barisal, 18. V. 1992, Coll. V. Biswas; 1 ♀, Potuakhali, 11.X.1992, Coll. V. Biswas.

Description: Female: Body broad, strong, longer than wide. Cephalothorax - longer than wide, posteriorly broad, anteriorly narrowing, clothed with pubescence saving the median cephalic region which medially with faint white stripes ; cephalic region raised, convex, clothed with small spines; cervical furrows deeply distinct (Plate - I, Fig. 1). Eyes brown, both rows of eyes recurved; median eyes slightly larger than laterals, situated on the median tubercles; ocular quad squarish. Thoracic region broad, radii distinct, clothed with brown spines. Chelicerae black, longer than wide, medially broad, ventral and dorsal margins clothed with hair-like spines, each of inner and outer margins with 4 strong teeth, fang segmented (Fig. 2 ). Maxillae brown-black, longer than wide, anteriorly broad, dorsal margin clothed with long spines, anteriorly scopulate (Fig. 3). Labium brown-black, longer than wide, medially constricted, anteriorly convex, bluntly pointed and scopulate (Fig. 3). Sternum black, longer than wide, nearly heart-shaped, anteriorly narrowing and pointed, anterior margin wavy (Fig. 4). Legs very long and slender; leg formula 1243 and the measurements (in mm) of different segments are shown in Table 1.

Male very small and dissimilar than female, light brown. Body longer than wide and nearly cylindrical. Male palp with terminal apophysis long and pointed, tegulum curved (Figs. 7 & 8).

Abdomen - long, cylindrical, anteriorly broad and wrinkled, posteriorly narrowed with an anterior brown transverse band, following posteriorly directed yellow longitudinal parallel bands; dorsum with many small, paired and unpaired sigillae and clothed with pubescence; ventrally with yellow patches; epigyne and internal genitalia as in Figs. 5 & 6.

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Distribution: Bangladesh: Bagerhat, Pirojpur, Potuakhali; Chna; India; Japan, USA; Philippines; (Tikader, 1982; Chen & Zhang, 1991; Yaginuma, 1986; Barrion & Litsinger, 1995).

Table 1. Measuremets (in mm) of different leg segments of Nephila pilipes (Fabricius).

Leg Femur Patella Tibia Metatarsus Tarsus Total

I 28.00/28.00 4.00/4.00 22.00/22.00 34.00/34.00 4.00/4.00 92.00/92.00

II 23.00/23.00 4.00/4.00 17.00/17.00 27.00/27.00 4.00/4.00 75.00/75.00

III 15.00/15.00 4.00/4.00 13.00/13.00 13.00/13.00 3.10/3.10 48.10/48.10

IV 21.00/21.00 4.00/4.00 17.00/17.00 20.00/20.00 5.00/5.00 67.00/67.00

2. Nephila nandiniae n. sp. (Figs. 8-16; Plate - I, b-c)

Material examined: Holotype - 1♀, Chitalmari, Bagerhat, Bangladesh, webs of trees, 17.6. 1993 (coll. VB). Allotype - 1♂, otherwise data same as for the holotype. Paratypes - 2♀♀ and 2♂ ♂, otherwise data same as for the holotype.

General: Female - Cephalothorax brown, anteriorly dark; legs brown-black; abdomen dark brown with yellow stripes. Male - Cephalothorax and legs orange-brown; palp yellow; abdomen brown. Total body length (holotype) 32.20 mm. Carapace 10.10 mm long, 10,00 mm wide; abdomen 20.10 mm long and 6.00 mm wide. Total body length (allotype) 5.20 mm. Carapace 2.00 mm long, 2.00 mm wide; abdomen 3.20 mm long and 1.00 mm wide.

Etymology - The species is named after Dr. Nandini Raychaudhury, Scientist, Indian Space Research Organization (ISRO), Ahmedabad, India.

Diagnosis - The closest ally of N. nandiniae n. sp. is N. pilipes (Fabricius) from which it stands distinct in the following characters - (1) Palpal organ longer than in N. pilipes. (2) Cymbium and terminal apophysis longer, narrowing and pointed anteriorly (Figs. 15 & 16). (3) Epigynum smaller with median septum, semilunar epigynal scape and much different internal genitalia (Figs. 13 & 14). (5) Labium broad; abdominal dorsum with wavy bands and 5 pairs of sigillae and cephalic region anteriorly truncate (Fig. 1).

Description - Both sexes dissimilar, females large, very longer than males. Cephalothorax and legs of male orange brown while in female cephalothorax dark-brown, anteriorly very darker and legs blackish – brown (Plate - I, Fig. 2-3). Abdomen of male brown and in female dark- brown with yellow stripes. Eye field dark brown, with very small setae, eye rows recurved, lateral eyes closed. Chelicerae dark brown, strong (Fig. 10). Maxillae and labium brown, broad, anteriorly scopulate (Fig. 11). Females with dark brown colour and blackish brown legs.

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Ventrally red-brown with numerous yellow spots. Sternum dark, typically heart-shaped, posteriorly narrowed and blunt (Fig. 12). Abdominal pattern comparable to N. pilipes (Fabr.) in appearance, with wavy margins and 5 pairs of sigillae on the dorsum.

Figs. 1-8: Nephila pilipes (Fabricius)

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1. Dorsal habitus; 2. Chelicerae; 3. Maxillae & Labium; 4. Sternum; 5. Epigynum; 6. Internal genitalia; 7. Male palp (lateral view, left); 8. Male palp (lateral view, right)

Female - Body length (TL) 32.20. Crapace dark-brown, length 10.10, width 10,00, height 5.10. Ocular quadrangle length 1.00, lateral eyes close. Distance ALE- AME 5.00, PME – PLE5.00. Eye diame-ters: AME 1.60, ALE 0.80, PLE 0.70. Cheliceral promargin with 2 and retromargin with 4 teeth (Fig. 10). Legs: Leg formula 1 – 2 – 4 – 3. Legs uniformly dark-brown except base of metatarsi; leg measurements shown in Table 2.

Table 2. Measurements (mm) of different leg segments of female Nephila nandiniae n. sp.

Leg Femur Patella Tibia Metatarsus Tarsus Total

I 20.20/20.20 4.00/4.00 15.30/15.30 25.20/25.20 4.00/4.00 68.70/68.70 II 19.00/19.00 3.003.00 14.00/14.00 22.00/22.00 4.00/4.00 62.00/62.00 III 12.00/12.00 2.00/2.00 7.00/7.00 12.00/12.00 3.00/3.00 36.00/36.00 IV 20.00/20.00 3.00/3.00 12.00/12.00 22.00/22.00 4.10/4.10 61.10/61.10

Abdomen extremely long, dark brown with yellow longitudinal stripes and 5 pairs of sigillae; ventrally red brown with yellow spots.

Epigynum: epigynal scape semilunar, thin, wide, anteriorly slightly high.

Male - Body length (TL) 5.20. CL 2.00, CW 2.00, CH 1.00. Ocular quadrangle length 0.35, lateral eyes close; distance ALE- AME 0.50, PME – PLE 0.82. Eye diameters: AME 0.30, ALE 0.19, PLE 0.20. Cheliceral promargin with 2 and retromargin with 4 teeth. Legs: Leg formula 1-2-4-3. Legs dark brown; leg measurements shown in Table 3. Palp: blackish-brown with sharp spines; patella and tibia brown. Apex of cymbium thinner and longer, terminal apophysis longer, pointed; tegulum broad (Figs. 15 & 16).

Table 3. Measurements (mm) of different leg segments of male Nephila nandinae n. sp.

Leg Femur Patella Tibia Metatarsus Tarsus Total

I 3.80/3.80 0.81/0.81 3.51/3.51 5.81/5.81 1.82/1.82 15.75/15.75 II 3.40/3.40 0.79/0.79 2.82/2.82 4.22/4.22 1.50/1.50 12.73/12.73 III 2.00/2.00 0.50/0.50 1.26/1.26 1.82/1.82 0.73/0.73 6.31/6.31 IV 3.49/3.49 0.65/0.65 2.50/2.50 3.72/3.72 1.44/1.44 11.80/11.80

-71- 10 16

15 11

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Abdomen elongate, dumbel shaped, light brown. AL 3.2, AW 1.00, AH 3.0; ventrally reddish-brown.

Distribution: Bangladesh - Bagerhat (type-locality).

10 16

15 11

♀ 9

12 14

Figs. 9-16. Nephila nandiniae n. sp.

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9. Dorsal habitus; 10. Chelicerae; 11. Maxillae & Labium; 12. Sternum; 13. Epigynum; 14. Internal genitalia; 15. Male palp (retrolateral view); 16. Male palp (ventral view)

ACKNOWLEDGEMENTS

Our sincere thanks are due to Late Dr. S.C. Majumder and Dr. Animesh Bal, Scientists, Arachnida section, Zoological Survey of India, Kolkata, for confirming the identity of the species and the Hon’ble Vice Chancellor, RKMVU, for all logistic support. We are also thankful to the teachers, Biology Department, Chitalmari College, Bagerhat, Bangladesh, for their kind assisstance during survey.

References

[1] Barrion, A.T. & J.A. Litsinger, 1995. Riceland spiders of South and Southeast Asia. CABI-IRRI, 700 p. [2] Begum, A. & V. Biswas, 1997. A list of spider fauna of Barisal division, Bangladesh. Bangladesh j. Zool. 25(2): 207-210 [3] Biswas, B.K. & K. Biswas, 1992. Araneae, Spiders. State fauna series - 3: Fauna of West Bengal 3: 357-500 [4] Biswas, V. 1995. Studies on the spider fauna (Araneae: Arachnida) of Bangladesh. Ph.D. thesis, Department of Zoology, University of Calcutta, 622 p. + 50 plates. [5] Biswas, V. & D. Raychaudhuri, 2012. Orb-weaving spiders of Bangladesh –II: Genus Larinia Simon (Araneae: Araneidae) with description of a new species. Rec. Zool. Surv. India, 112 (3): 53-59. [6] Biswas, V., H.R. Khan, N.Q. Kamal & A. Begum, 1993. A preliminary study of the rice-field spiders of Jhenaidah. Bangladesh J. Zool. 21(1): 85-92. [7] Chen, Z.F. & Z.H. Zhang, 1991. Fauna of Zhejiang, Araneida. Zhejiang Sci. & Tech. Pub. House, 556 p. [8] Chowdhury, S.H. & S. Nagari, 1981. Rice field spiders from Chittagong. Proc. Zool. Soc. Bangladesh: 53-72. [9] Dyal, S. 1935. Fauna of Lahore - 4. Spiders of Lahore. Bull. Dept. Zool. Panjab Univ. 1: 119-252. [10] Kaston, B. J. 1972. How to know the spiders. 2nd Edition, W.M.C. Brown Pub. Co., Dubuque, Iowa, 289p. [11] Okuma, C., N.Q. Kamal, Y. Hirashima, Z. Alam & T. Ogata, 1993. Illustrated Monograph on the rice-field Spiders of Bangladesh. IPSA-JAICA, Salna, Gazipur, 93p. [12] Pocock, R.I. 1900. The Fauna of British India, Arachnida. Taylor & Francis, London, 279p. [13] Robinson, M.H. & B. Robinson, 1973. Ecology and behaviour of the giant wood spider Nephila maculata (Fabricius) in New Guinea. Smithson. Contrib. Zool. 149: 1-73.

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[14] Song, D.X., M.S.Zhu & J. Chen, 1999. The Spiders of China. Hebei Sci. & Tech. Pub. House, 640p. [15] Thorell, T. Descriptive Catalogue of the spiders of Burma. British Museum (Nat. Hist.), London, 406p. [16] Tikader, B.K. 1982. Fauna of India, Spiders (Araneidae). Vol. 2(1), Zoological Survey of India, Kolkata, 293p. [17] Tikader, B.K. 1987. Handbook on Indian Spiders. Zoological Survey of India, Kolkata, 251p. [18] Tikader, B.K. & B. Biswas, 1981. Spider fauna of Calcutta and Vicinity. Rec. Zool. Surv. India, occ. Pap. No. 30: 1-149. [19] World Spider Catalog. 2019. World Spider Catalog. Natural History Museum Bern. Available at http://wsc.nmbe.ch, version 20.0 (Accessed on 25.1.2019). [20] Yaginuma, T. 1986. Spiders of Japan in colour. Hoikusha Pub. Co. Ltd., Osaka, 305p. [21] Zhao, J.Z. 1993. Spiders in the cotton fields in China. Wuhan Press, China, 552p. [22] Zhu, M.S., D.X. Song & J.X. Zhang, 2003. Fauna Sinica: Invertebrata, vol. 35 (Arachnida: Araneae Tetragnathidae). Science Press, Beijing, vii + 418p.

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PLATE – I

A) Nephila pilipes ♀: dorsal habitus B) Nephila nandiniae n. sp. ♀: dorsal habitus

C) Nephila nandiniae n. sp. ♂: dorsal habitus

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