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Home , Nephila, Nephila pilipes, Nephilinae

I J R B A T, Special Issue Feb 2016: 146-150 ISSN 2347 – 517X

INTERNATIONAL JOURNAL OF RESEARCHES IN BIOSCIENCES, AGRICULTURE AND TECHNOLOGY © VISHWASHANTI MULTIPURPOSE SOCIETY (Global Peace Multipurpose Society) R. No. MH-659/13(N) www.vmsindia.org

THE SYSTEMATICS AND BIOLOGY OF THE PILIPES AND CLAVIPES (FAMILYNEPHILIDAE) IN THE GADCHIROLI REGION (M.H.)

Ghaturkar Shivkumar Revankumar Dept. of Zoology M. G. College Armori [email protected]

Abstract: Gadchiroli district is famous for glory of forest and it is considered to be one of the rich areas of eastern Maharashtra as well wild life diversity of flora and fauna is seen among the dense forest region. Gadchiroli district is located in south –eastern corner of Maharashtra State in India and is bounded by Chandrapur district to the west, Gondia district to the north Chhattisgarh state to the east and Telangana state to the south. The main river basin of the district is Godavari which flows to west to east and form southern boundaries. The major tributaries of Godavari are Indrawati and Pranhita which is turn from by the confluence of the Waingangā and the Wardha near Chaprala village. Aheri and Sironcha Talukas in the eastern part of the district are covered by the forest. Hills are found in Bhamragad, Tipagad and Palasgad and Surjagad area. The average area covered by Gadchiroli district is 14,412 km 2among which 79.36% area covered by forest. The spider as a group is one of the most abundant pre datory groups in terrestrial ecosyste ms with more than 40,000 described species. These are famous for extreme sexual size dimorphism in which males are many times smaller than the giant females. In the present observation, were identified and recorded for morphological structure and diversity. But the conse rvation efforts are limited due to lack of documentation and studies on this area. This study was designe d not only to document species richness of this small area but also to find out distribution patterns of these spiders along various microhabitats along the Gadchiroli district, eastern part of Maharashtra. Keywords: and Ne phila clavipes; biodiversity, richness, Gadchiroli, Maharashtra.

Introduction :  For spide rs enthusiasts who are keen The golden orb spider Nephila pilipes and Nephila to learn about its morphology, anatomy clavipes are a common species of spider that and how to go about indentifying one. can be found in the primary and secondary forest of Maharashtra and its e astern part of Material and Methods: Gadchiroli district. Nephila pilipes (Fabricius The present study was carried out from June 1793) and Nephila clavipes (Linneus) occurs in 2014 to May 2015. The observation were carrie d the closed forests of eastern area of out by using a field binocular (10x50 Maharashtra. They are probably best known to magnification) during the morning (6 to 11 AM) the public for their ability to build large, and in the evening (4 to 7 PM) and the spider spectacular we bs with spide r silk that is population was estimated by direct count stronger than Kevlar. However, large webs mean method. After detection, specime n was for more number of prey caught.Like all spide rs photographed by using came ra photographs are from the family Nephilidae ,female gigantism is taken and identified with the help of keys and extremely pronounced and this results in large methods suggested by Joseph K H Koh. Few of sizes of mature female spide rs achieving body them are collected using colle ction bag. le ngths of 40 mm to 60 mm. Despite its huge Result and Discussion: size and common status, it is surprising to note that there are not many studies which focus on ABOUT NEPHILA: its biology, unlike its American counterparts An orb weaver producing silk from its (Nephilaclavipes ). Recent studies demonstrated spinnerets. The abdomen has no appe ndages that golden orb weaving spiders (Nephila ) is except those that have been modified to form most promine nt and most researched tropical one to four pairs of short, movable spinnerets, (Kuntner, 2005, 2006, 2007a; Harvey which emit silk. Each spinneret has many et al., 2007). spigots, each of which is connected to one silk Hence, this species hopes to se rve for two gland. Silk is mainly composed of a protein very purposes: similar to that used in insect silk. It is initially a  Asan interesting read for whomeve r that liquid, and hardens not by exposure to air but is interesting in finding out more about as a result of being drawn out, which changes its biology. the internal structure of the protein. It is similar in tensile strength to nylon and biological materials such as collagen, chitin and cellulose,

146 I J R B A T, Special Issue Feb 2016: 146-150 ISSN 2347 – 517X

but is much more elastic in nature. In othe r scope of the current study, but rather serves to words, it can stretch much further before provide complementary biological information to breaking or losing shape. Some spiders have support the taxonomic revision undertaken cribellum, a modified spinneret with up to here. 40,000 spigots, each of which produces a single WEB STRUCTURE: ve ry fine fibe r. The fibe rs are pulled out by the Nephila spp. construct large orb-webs calamistrum, a comb-like se t of bristles on the that are asymmetric inshape and include jointed tip of the cribe llum, and combined into a extensive yellow silk elements ‘golden orb- composite woolly thread that is ve ry effective in weavers’. The orb of most adult Nephilas is0.5– snagging the bristles of insects. The earliest 1.0 m in diameter, but the extensive anchor spiders had cribella, which produced the first lines, frame andbarrier web substantially extend silk capable of capturing insects, be fore spiders the dimensions of the structure.These are developed silk coated with sticky droplets. enhanced further when females aggregate Howeve r most modern groups of spiders have (Rypstra1985) and the webs become connected lost the cribellum. and therefore continuousover many square Females are large r in size and grow to a me ters.The orb is asymme tric in that the hub is body size of 30-50mm (ove rall size up to 20 centered inthe upper part of the web, so that the mm), with males growing to 5-6 mm. it is one of sticky elements of the preycatching area are the biggest spide rs in the world.Legs of spider is concentrated disproportionally in the lowerhalf made up of seve ral parts, coxa,trochanter of the web (Robinson and Robinson ,femur , patella ,tibia ,me tatarsus , tarso and at 1973). Nephila remain permanently in their the tip of tarso the re is presence of hairs known webs,which are they permanent structures that as artigli .mouth parts consists of artigli dei function as aprey-catching device during both , mandible ,maxilla ,labium ,labrum the day and night. As a consequenceboth which he lps in mastication of foods. On each juveniles and adult females are possibly sides of abdomen there is presence of spiracles moreexposed to diurnal hunting predators over which helps in respiration. Sense organs relatively longperiods of time , and the ir webs are consists of photoreceptors eyes which are made exposed to damage frombirds, grazing mammals of near about 2000 ommatidia lenses ,ocelli and large insects. Several physical each and tango receptors hairs on the surface andbehavioral adaptations have resulted to . minimize these effects.The extensive ‘barrier’ BIOLOGY OF NEPHILAS ( Nephilapilipes and web either side of the orb of large juvenilesand Nephila clavipes): adults has been postulated by Higgins (1992 a) Compared with most spide rs, the toprotect or warn the resident spider of large biology of Nephila has beenwell studied, mostly aerial predators.Aggregating behavior, whe re the for one species, N. clavipes from theNew World, webs of multiple females areinterconnected, which has become a favoured model for further reduces , but the results of research onthe reproductive biology and studies to examine the functionof this be haviour behavior of orb-weaving spiders. Biological are contradictory. For N. clavipes , studiesby information on Nephila pillipes for the Rypstra (1985) indicate thataggregating behavior Australianregion has been gradually has positive be nefits for prey captureefficiency accumulating since the early work on N. pilipes and reduced predation, while Farr (1976) (= N. maculata ) from New Guinea (Robinson and proposedthat ‘web clumping’ is a random Robinson 1973, 1976, 1980) and N. plumipes process influenced by populationdensity and from the Sydney region (misidentified as N. results in decreased predation success. edulis).More recently, nume rous authors Contrasts with members of the sister , (Herberstein and Elgar 1994; and Vollrath L.Koch, where the spiders are 1998 a, 1998 b; Schne ider et al . 2000); Here we positioned in their web at night andin a retreat present a summary of what is known about the during the day (Kuntner 2007).Juveniles biology of Nephila pillipes . from Gadchiroli and some times construct a ‘stabilime ntum’ above briefly compare these findings with the major andbelow the hub (Robinson and Robinson works published on N. clavipes and othe r 1973, 1974 a, 1978 a). In N. pilipes species from outside Gadchiroli district in an stabilimentahave only been obse rved in 5% or attempt to highlight similaritie s and differences less of juvenile webs. This structure has been among taxa and regions. It should be noted that examined experimentally in a range oforb- this section does not represent a comprehensive weaving spide rs and may act to reducedamage review of Nephilas biology, which was beyond the by birds (Eisne r and Nowicki 1983), although

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I J R B A T, Special Issue Feb 2016: 146-150 ISSN 2347 – 517X

this maynot be the only function of stabilimenta moving their webs (Vollrath 1985), and this (Robinson andRobinson 1973, 1974 a; phenomenonmay be common for several Herbe rstein et al . 2000; Bruce 2006). Nephila species. However, the frequency of occurrence also characteristically places wrapped prey in a and selective advantage of thebehaviour is line above or below the hub. Apart from acting unclear given that N. piliipes also shifts its as a food reserve, this structure also serves websrandomly, independent of prey availability. othe r functions,if partly damaged, the webs of N. Nephilas spp. is also known to construct food pilipes arerepaired by the resident spider within caches,usually above the hub of the web, which 10–60 min after disturbance ,but if the damage are utilized when thereis a shortage of is severe, the spider will usuallyconsume the food.Caches vary in size and composition and remaining web, rest in the vegetation and then are influenced by preydensity, encounter rates constructa new web at the same or a nearby and prey type .Large caches may contain as locality. Repeated disturbanceof the web or lack many as 12–15 prey items and maybe 10–12 cm of prey inevitably results inrelocation of the web in length. When prey is added to the cache it is to a nearby site, usually within 2–10 usually dense ly wrapped in silk and placed at meter.Gravid females do not repair their webs e ithe r the topor bottom of the cache so the for the few days beforeoviposition and they can connected prey forms a near vertical line. appear somewhat tattered if damagedduring this MATING: time (Robinson and Robinson 1973). Mating behaviour of Nephilas has been PREY AND FEEDING: well documented for seve ral species including Nephila spp., like most diurnal orb- those found inGadchiroli. In addition, it has we ave rs, is opportunisticthough sometime s been used to examine more fundamental se lective predators, feeding on any suitableprey aspects of mating systems in spiders, that adheres to their web. Various studieshave particularly the evolution of sexual documented a large numbe r of prey groups, sizedimorphism, sperm competition and sexual includingvarious species of Orthoptera, Diptera, cannibalism (Vollrath and Parker 1992). Coleoptera, Lepidopteraand, generally to a lesse r Nephilas is typified by extreme sexual size degree, Hymenoptera and Odonata .Most we ll dimorphism whe re males can be 4–10 times studied Nephila spp.have also been observed to smaller than females. Once male s reach avoid or remove particular insectsfrom their adulthood in early summe r they leave their own we bs without feeding on them. These include web and search for those of mature or subadult vespid wasps alate ants (Higgins females, possibly using web characteristics and 1987),‘unpalatable’ butterflies and nume rous web-based chemical cues to locate and ‘obnoxious’ groups including lycidbeetles, recognize specific webs . Although short- Hemiptera and Neuroptera that produce distance pheromonal stimulation of males distastefulsecretions (Robinson and Robinson ispostulated for Nephilas , there is no evidenceof 1973). Nephilas is clearly able to deal with a long distance phe romone-based attraction to largesize range of prey,from 2 mm in length up femalewebs. It is common for multiple males to to insects larger and heavier thanthe mse lves. occupy the web of asingle female, who normally The study found that have examined the mates with more than one male(Elgar et al . predatorybehaviour of Nephila . In brie f, these 2003 a). Furthe r, male s will alter the show that the stimulus for orientation frequencyand duration of copulation depending andapproach is mediated through web on the number and size ofcompeting males in vibrations, and that the attack behavior varies the same web, and the mating history of for prey of different sizes. Essentially, small pre y the female (Elgar et al . 2003 a, 2003 b). aresimply ‘seized and removed’ from the web, is generally while large prey arebitten by the resident spide r uncommon in orb-we avingspide rs, but in that the n waits for the venom tosubdue the prey Nephila spp. its frequency differs among be fore it is cut out of the web and wrapped species(Robinson and Robinson 1980;) but also insilk (Robinson 1971; Robinson and possibly a result of e nvironme ntal,behavioural Robinson1973). Predatory behaviour also and physiological factors such as time of the changes dramatically from theearly free-living year,nutritional and reproductive state of the spider ling stage , when the y live in a communal female, age of thefemale, and number and size we b and apparently feed opportunitistically, of males on the web (Schneide r et al . 2000; tosecond and third instars that capture live prey Elgar and Schne ider 2004). Severalbehavioural in individual webs.Adult females of N. adaptations in males have been identified that clavipes respond to decreased food availability by act toreduce sexual cannibalism. In particular

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this includes matingwith newly moulted adult complex prematingbehaviour that includes the females that are largely inactive , andmating male laying down a fine mat of silkon the dorsal when the female is feeding, but also, to a lesser side of the abdomen and pedicel of the degree,approaching the female on the opposite female;matings are of much longer duration side of the orb web.Matingbehaviour in N. pilipes which is of 30 min,are far less aggressive and departs significantly from that de scribed for the sexual cannibalism appears to bevery rare abovespecies. Nephila pilipes has a more (Robinson and Robinson 1973, 1976).

A B C

D E

Fig . A and B showing dorsal side of Nephilla clavipes Fig C showing dorsal side of Nephillapilipes Fig. D showing mating Nephilla pilipes ,Fig.E. Represent map of Gadchiroli district where spide r commonly occurred.

Aknowledgement: species of Nephilas spp. is exactly match with I am thankful to Proff. Jaye sh Papadkar for his Nephilas spp. In Gadchiroliregion. assistance and allowing me to conduct this research study in the given area. Materials and References: supplies needed for ide ntifying these spiders will Elgar, M.A., 1991. Sexual cannibalism, size not be available without the research support dimorphism, and courtshipbehavior in orb- provided by NRCP. weaving spiders (Arane idae). Evolution 45,444– 448. Conclusion : Harvey, M.S., Austin, A.D., Adams, M., 2007. From above all information it is conclude that The systematic and biology of the spider genus the data written over the world wide spider Nephila (Araneae : Nephilidae) in the Australasian region. Invert. Syst. 21, 407–451.

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Herbe rstein, M.E., K.E. Abernethy, K. Robinson, M.H., 1975. The evolution of Backhouse, H. Bradford, F.E. de Crespigny, P.R. predatory behavior in araneidSpiders. In: Luckock & M.A. Elgar. 1998. The effect of Baerends, G., Beer, C., Manning, A. (Eds.), feeding history on prey capture behaviour in the Function and Evolution in Behavior. Clarendon orb-web spider Argiope keyserlingii Karsch Press, Oxford, pp. 292–312. (Araneae: Araneidae). Robinson, M.H., 1982.Courtship and mating Higgins, L.E., 1989. Effect of insemination on behavior in spiders. the morphology of the internal female genitalia Robinson, M.H., Robinson, B., 1973. Ecology of the spider Nephila clavipes (Araneae: Arane idae). and behavior of the giant wood spide r Nephila maculata (Fabricius) in New Guinea. Smithson. Kuntner, M., 2005. A revision of He rennia Contrib. Zool. 149, 1–73. Robinson, M.H., (Araneae, Nephilidae , Robinson, B., 1980. Comparative studies of the courtship and mating behavior of tropical ), theAustralasian’’coinspiders‘‘. araneid spiders. Inve rt. Syst.19, 391–436. Rypstra, A.L. 1981. The effect of Kuntner, M., 2006. Phylogenetic systematics of kleptoparasitismon prey consumption and web the Gondwananephilid spider lineage relocation ina Peruvian population of the spider Clitae trinae (Araneae, Nephilidae). Zool.Scr. 35, Nephilaclavipes. Oikos 37:179–182 19–62. Schneider, J.M., Elgar, M.A., 2001. Sexual Kuntner, M., 2007a. A monograph of cannibalism and spermcompetition in the Nephilengys, the pantropical golde n orb-web spider Nephila plumipes “Hermitspide rs”(Araneae, Nephilidae, ().female and male perspectives. Nephilinae). Syst. Entomol. Behav. Ecol. 12, 547–552. 32, 95–135. Vollrath, F., Parker, G.A., 1992. and distorted sexratios in spiders. Kuntner, M., 2007b. Nephilidae.Com: a Web Nature 360, 156–159. Re source for Nephilid Vollrath F. 1988. Spider growth as an Indicator Spiders (Araneae, Araneoidea, Nephilidae ), of habitat quality. Bulletin of the British Ve rsion 1.3. Online at Arachnological Society 7, 217-219. http://www.nephilidae.com/ . Linnaeus, C., 1767. Araneae. In: Systema naturae per regna trianaturae , secundum classes, ordines, genera, species, cum characteribusdifferentiis, synonymis, locis. Editio duodecima, reformata.L. Salvii, Holmiae, 1, 533–1327. pp. 1030–1037

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