Some notes on distribution, ecology and conservation Poecilotheria pederseni Kirk, 2001(Family: Theraphosidae) L. D. Chaminda Bhathiya Kekulandala 1 and W.L.D.P.T. Sampath de A. Goonatilake 2 1 144/10, Raymond s Range, Galthude, Panadura, bkekulandala@gmail.com 2 IUCN- The World Conservation Union, Sri Lanka Country Office, 53, Horton Place, Colombo 07, Sri Lanka. Correspond: bkekulandala@gmail.com Introduction Family Theraphosidae (Theraphosids) is classified under suborder Orthognatha and infraorder Mygalomorphae (Smith and Kirk, 2001; Raven, 1985). Theraphosids can be distinguished from other Mygalomorph families by having; tarsal tufts at the apex of the tarsi at all the legs and a distinct lobe on the anterior maxillae or coxa of the pedipalp (Smith and Kirk, 2002). Family Theraphosidae is further divided into 12 subfamilies and genus Poecilotheria is classified under subfamily Selenocosmiinae (Pocock, 1900, Raven, 1985). The Selenocosmiins characterized by prolateral maxillae face with numerous bacilliform setae (lyra) acting against short or spike shaped setae on the retro margin of the cheliceral furrow; no utricating hairs on abdomen (West, 2001). The diagnostic character of genus Poecilotheria is the stridulating organ, which has 4 to 8 rows of mixed modified setae at the outer face of the chelicerae (Smith and Kirk 2002). The lower line is made up of tapering medium to long, straight or gently curved setae. These spiders are generally large, variegated arboreal spiders with distinct patterns on the underside of the body. Hence these markings can be used as diagnostic tools to define species. In Sri Lanka, genus Poecilotheria is represented by five species and all of them are endemic to Sri Lanka (Smith & Kirk, 2002). The taxonomic history of Sri Lankan theraphosids goes back to early 1800. In 1804, Latreille first described the P. fasciata. Since then, Koch (1850), Pocock (1895, 1899), Stand (1913), Charpentier (1996), and Kirk (1996, 2001) were contributed to taxonomy of Sri Lankan Theraphosids. In 2001, Peter Kirk described Poecilotheria pederseni, which was taken from Hambantota district in Sri Lanka. Diagnostic characters P. pederseni can be identified by using following combination of characters given by Kirk 2000, radiating marks on the cephalothorax, foliage marking on the abdomen is pointed towards the cephalothorax, presence of a thick black band on the femur of the first leg, very pale yellowish color on the femur of the first leg. The most distinct character is the
presence of a triangular marking on the femur of the fourth leg running from proximal end of the femur to the distal end (Kirk, 2000). Ventral: legs 1 and 2 are identically marked. The coxa and trochanter are black. There is a very narrow black band on the proximal edge of the femur and a black band about three quarters of the length of the femur distally. There is a very pale band, almost white, on the distal edge of the femur. The same pale colouring on the rest of the femur is unlike any other Sri Lankan Poecilotheria species. In fact, the only other species of Poecilotheria to exhibit this pale coloration is P. formosa Pocock 1899. The patella has a broken black band distally with the remainder being white. The tibia is white with a thick black diagonal band proximally. The metatarsus and tarsus are fully scopulate and black. Leg 3; again, the coxa and trochanter are black. The femur has a thick black median line, which narrows slightly distally, and there is also a distal transverse black line. The ground colour is, again, almost white. The patella is white with a broken black band distally. The tibia is white proximally with an irregular transverse black band and a narrow, white distal edge. The metatarsus is ¾ scopulate distally and the tarsus is fully scopulate. Leg 4; the coxa and trochanter are black. Again, there is a median black line down the femur, this time narrowing to a point giving a distinctive triangular marking. Distally, there is a black transverse band, but unlike leg 3 it does not meet up with the median line. The patella and tibia are identical to leg 3 and the metatarsus is only ½ scopulate distally. There is no other species of Poecilotheria in either Sri Lanka or India that has these distinctive markings on legs 3 and 4 Current status of distribution This species was previously known only from Hambanthota as decribed in the type paper by Kirk (2000). In fact Hambantota district is a large administrative division, which encompasses variety of habitat and ecosystem types. However the first record of this species was made in 1997 by the second author. It was recorded from Palatupana- Wana Niwahana (Wildlife department bungalow) at Ruhuna (Yala) National Park (Hambantota District) and also made some notes on its ecology. But it was mistakenly identified as a P. fasciata at that time and this was made 4 years before the P. pederseni described by Kirk in 2001. (Goonatilake, 1997). After the species described in 2001, authors were able to record it in natural habitat for the first time in Ravana Ella Sanctuary (Monaragala District) in 2001 based on a moult. This record took place during a field visit of the workshop on Sri Lankan Theraphosids organized by The Department of Wildlife Conservation and US Fish and Wildlife Service. Peter Kirk, who was the resource person for the workshop confirmed the identification. This site situated near the Ravana Ella Falls in the second peneplains at an altitude of 600 m from the mean sea level and it belongs to in the intermediate climatic zone. Thereafter P.
pederseni was recorded in Ella, which is situated in a higher elevation than Ravana Ella. This is the highest elevation that P. pederseni recorded so far. All other locations are in the lowlands near the coastline in the southern arid and dry zones of Sri Lanka. Therefore, it quite evident that, P. pederseni is more widely distributed in Sri Lanka than previously expected. We were able to observe, record and verify the sightings by photographs and drawings of P. pederseni in following locations, Bundala National Park (2003), Jaburagala Camp site, Block I, at Ruhuna (Yala) NP (2002), Near Manik River, Block II, at Ruhuna (Yala) NP (2003), Near the Uddakandera Temple at Thissa-maharama (2002), Diulpathana tank at Thissamaharama (2002) in Hambantota District; Kuda Gal Amuna, Block V, at Ruhuna (Yala) NP (2002), Weheragala, Block V, at Ruhuna (Yala) NP (2002), Ella (2002), Vallavaya (2004), Maragala forest reserve in Monaragala district (See Map 01). Habitat The Ravana Ella moult was observed in a hole of a Bo tree (Ficus religiosa). Surrounding vegetation is basically a Gully forest (small patches of forests situated in gullies in mountainous areas) surrounded by Dry Patana mixed savanna type grasslands. Terrain is very steep and a seasonal stream flows nearby. Other specimens were observed within the trees with tree holes and dead hollow tree trunks. Few moults were found near the Manik River at Block II in Ruhuna NP and all the moult were recorded from small trees which the GBH less than 20cm. The moult cephalathorax size also less than 1.5cm. Furthermore this species was also observed inside buildings also and this species frequently observed in the staff quarters of the Bundala national park. This indicates the ability of the species to adapt to human (built up) environment. Web Does not weave a broad web. Nevertheless, it forms a comfortable mansion in and around the opening of its den. In captivity it weaves a small web corner of its cage, few days before the ecdysis (Goonatilake, 1997). Diet In captivity it feeds on Cockroaches (Periplaneta spp. and Blata spp.) other fleshy insects and Geckoes (Hemidactylus spp.) (Goonatilake, 1997). Threats and conservation:
Habitat loss due to various human interventions is a major threat. Natural forest areas are slowly diminishing as many forest areas are converted for agricultural lands. The shifting chena cultivation is a major livelihood for people in the Hambanthota and Monaragala districts, where the P. pederseni is distributed. The Degraded remnant forest patches and the protected areas (eg: Bundala National Park, Udawalawe National Park, Lunugamvehera National Park, Yala National Park and Rawana Ella Sanctury) in these districts are also under severe pressure from the surrounding local communities for their subsistence livelihoods. Although we thought Poecilotheria pedeseni to be habitat specific, it was observed both in natural and man-made habitats. For instance we managed to observe this specimen under a plastic water tank in staff quarters of the Bundala National Park. According to the officers of the Bundala National Park, these spiders have been observed inside the houses also. Lack of awareness among local communities is another major problem. Theraposids are killed indiscriminately because they think theraposids are deadly poisonous. It has to emphasize that there has not been a documented human death caused by theraposid biting. Acknowledgments Authors wish to thank Mr. Mendis Wickramasinghe, Mr. Rohan Pieris, and Mr. Suranjan Fernando for providing photographs and drawings made from various sites. Mr. Pradeep Samarawickrama for sharing literature. Mr. Peter Kirk and Mr. Andrew Smith of British tarantula society for providing literature and confirming species. References Smith, A.M. and P. Kirk (2001) A field guide on the theraphosid spiders of Indian and Sri Lanka particularly the Genus Poecilotheria. (Unpublished) Raven, R.J. (1985) The spider infraorder Mygalomorphae (Araneae): Cladistics and systematics. Bulletin of American Museum of Natural History. 182: 1-180. Latreille, P.A. (1804) Tableau methodique des Insectes. Nouv. Dict. D Hist. Nat., Paris 24:129-295. Koch, C.L. (1850) Ubersicht des Arachnidensystems. Nurnberg, Heft 5, pp. 1-77. Pocock, R.I. (1895) On a new and natural grouping of some of the Oriental genera of Mygalomorphae, with description of new genera and species. Annals and Magazine of Natural History. 6 (15): 164-184. Pocock, R.I.(1899) Diagnosis of some new Indian Arachnida. Journal of the Bombay Natural History Society. 12: 744-753.
Charpentier, P. (1996) A new species of Poecilotheria from Sri Lanka: Poecilotheria pococki, sp. n. Exothermae Mag. 1:21-33. Kirk, P. J. (1996) A new species of Poecilitheria (Araneae: Theraphosidae) from Sri Lanka. British Tarantula Society Journal 12: 20-30. Kirk, P.J. (2001) A new species of Poecilitheria (Araneae: Theraphosidae) from Sri Lanka.. British Tarantula Society Journal 16: 77-88. Goonatilake, W.L.D.P.T.S.de A.(1997). Some notes on giant spider Poecilotheria fasiata (Latreille) Family: Theraphosidae. (Arachnida). Sri Lanka Naturalist. 1(1):5-6. Rick C. West, 2001. Pet Trade in Tarantulas and Conservation Strategies for Poecilotheria Spp. Bugs R All, Vol. 5 No. 2, December 2001, Newsletter of the Invertebrate Special Interest Group. Pocock, R.I. 1900. The fauna of British India including Ceylon and Burma Arachnida). Taylor and Francis, London.