NEW RECORD ZOOS' PRINT JOURNAL 19(11): 1696 FIRST RECORD OF MACRACANTHA ARCUATA FABRICIUS, 1793 (ARANEAE: ARANEIDAE) FROM ASSAM, INDIA Sanjay Molur 1 , B.A. Daniel 2 , Manju Siliwal 3 1,2 Zoo Outreach Organisation, 1,3 Wildlife Information Liaison Development Society, 29-1, Bharathi Colony, Peelamedu, Coimbatore, Tamil Nadu 641004, India Email: 1 herpinvert@vsnl.com; 2 icinsa@vsnl.net; 3 manjusiliwal@rediffmail.com web supplement 1696 Manuscript 1225; Received 7 July 2004; Finally accepted 20 September 2004; © Zoo Outreach Organisation; www.zoosprint.org November 2004 Twelve species of Genus Gasteracantha (Araneidae) are found in India (Platnick, 2004). Dahl (1914) considered Gasteracantha arcuata Fabricius, 1793 under subgenus Macracantha of genus Gasteracantha Sundevall, 1833. Emerit (1974) elevated it to a genus, which is followed by Platnick (2004) in his catalogue of the spiders of the world. Macracantha arcuata Fabricius, 1793 (Araneidae) is the only representative of this genus and occurs in India and from China to Borneo (Myanmar, Thailand, Malaysia, Singapore and Indonesia) (Pocock, 1900; Tikader, 1982; Koh, 1996; Platnick, 2004). In India, Macracantha arcuata is reported from Shillong in Meghalaya and Sikkim (Tikader, 1982; Biswas & Majumder, 1995, Platnick, 2004). On a trip to the Gibbon Wildlife Sanctuary (26 0 41'6.0''N & 94 0 21'6.2''E, elevation 136m), Jorhat, Assam on 21 October 2002 the first two authors observed many webs of Nephila pilipes Fabricius, 1793 (Tetragnathidae) along the entire stretch of 2.5 kms from the railway crossing (Ranger’s Office) to the Gibbon pool. This tropical wet evergreen forest famous for the Western Hoolock Gibbon Bunopithecus hoolock hoolock, is home to Macracantha arcuata. The orb webs of this species were seen commonly along with the Nephila webs and in two instances adult females were seen resting under the nearest leaf anchoring one of the radiating web strands. Although many webs we sighted were empty, we presume that the females rested under leaves rather than wait in the hub of the orb like many Gasteracantha species. The spider was identified as Macracantha from photographs taken from the site (Image 1 w ). Although the photographs were not very good, the spider was still identified using available descriptions from literature such as Pocock (1900), and Tikader (1982), and from a photograph published by Koh (1996). Unique characteristics differentiate this species from other closely related and similar looking Gasteracantha species; in that the median spine is more than three times the width of the abdomen. The description provided by Tikader (1982) indicates the colour of the abdomen of the preserved specimen as being brown, while the colour photograph of a live specimen from Bukit Timah Nature Reserve, Singapore shown in Koh (1996) clearly shows the colour to be red. The individuals we saw were deep red with all other morphological characters such as the number and shape of sigilla, spines and other characteristics on both dorsal and ventral side matching. The web was a typical orb-web three to four feet in diameter with conspicuous beads at the junction of the radiating and concentric strands. The web as such was conspicuously whitish, and slightly thicker than the gigantic orb-webs of Nephila pilipes. The number of conspicuous empty webs along with occupied Nephila webs piqued our interest in investigating further, when we saw this curved spiny spider under the leaves supporting one of the radial anchor strands. Macracantha arcuata is a rare spider and has been reported in India only from Shillong and Sikkim although the Sikkim report seems to be very vague. The present sighting could be the first record for Assam with the distance from the last sighting in Shillong in Meghalaya being at least 330km northeast. This finding represents a new locality record for the monotypic species in India. REFERENCES Biswas, B. and S.C. Majumder (1995). Araneae: Spiders, pp. 93- 128. In: Anon (Ed.). State Fauna Series 4: Fauna of Meghalaya, Part 2. Invertebrates. Zoological Survey of India, Calcutta. Dahl, F. (1914). Die Gasteracanthen des Berliner Zoologischen Museums und deren geographische Verbreitung. Mitt. zool. Mus. Berlin 7: 235- 301. Emerit, M. (1974). Arachnides araignées Araneidae Gasteracanthinae. Faune Madagascar 38: 1-215. Fabricius, J. C. (1793). Entomologiae systematica. Hafniae 2: 407- 428. Koh, J.K.H. (1996). A Guide to Common Singapore Spiders. Singapore Science Centre, Singapore, 160pp. Platnick, N.I. (2004). The World Spider Catalog, Version 4.3. American Museum of Natural History. Online at http://research.amnh.org/ entomology/spiders/catalog81-87/index.html. Accessed on 23 March 2004. Pocock, R.I. (1900). The Fauna of British India, including Ceylon and Burma: Arachnida. Taylor & Francis, London, 279pp. Tikader, B.K. (1982). Fauna of India Spiders: Araneae Vol. II Part 1 Family Araneidae (= Argiopidae) Typical Orb-weavers, Part 2 Family Gnaphosidae. Zoological Survey of India, Calcutta, 536pp. w See Image 1 on the web at www.zoosprint.org View publication stats View publication stats