Short Communication Preliminary checklist of spider fauna (Araneae: Arachnida) of Chandranath Hill, Goa, India

The present investigation is a very first attempt to generate the checklist of spiders from Chandranath Hill, Paroda, Quepem, Goa. A preliminary study was conducted from June 2018 to March 2020 to document the spider diversity from the region. In all, 125 species of spiders belonging to 102 genera from 19 families were identified. The dominant families were Salticidae followed by Araneidae. Guild structure analysis revealed six feeding guilds, namely, orb weavers, foliage runners, ground runners, stalkers, space-web builders and ambushers. This study has not only highlighted the need for conservation of this ecosystem due to the significant species diversity and endemic species but has also filled the lacuna of spider study in Goa to form the foundation for further investigation. Extensive research on the spiders from Chandranath Hill in the future can certainly expect further new discoveries.


PLATINUM OPEN ACCESS
Currently, the world list of spiders comprises over 48,000 species belonging to more than 4,000 genera and 128 families (World Spider Catalog 2020), of which, 1,843 species from 472 genera and 60 families are reported from India (Caleb & Sankaran 2020). In Goa, a total of 11 families belonging to 28 genera and 39 species have been documented till date (Bastawade & Borkar 2008).
The present study aims to generate a primary report documenting the spider diversity of Chandranath Hill, thereby highlighting the ecological aspect of this ecosystem.

Study area
The Chandranath Hill (15.213 0 N & 74.037 0 E) situated in Paroda, Quepem Taluka of South Goa District stands at a height of approximately 350m. Commonly known as Chandreshwar, this Hill has an area of approximately 2km 2 . This heavily wooded hill commands a panoramic view and its surroundings are enchanting accompanied with thick vegetation with riparian patches. The speciality of this hill is that it is geographically not connected to the Western Ghats yet it is rich in biodiversity. Despite this, no study on spiders has been carried out in this area till date, thus making it an important reason for conducting this exploration which will in-turn generate primary data with the help of this documentation. The study was conducted for a period of 22 months, from June 2018 till March 2020, covering all the seasons.

Climate and vegetation
The study area being close to the Arabian Sea J TT experiences warm and humid climate for most of the year with atmospheric temperatures ranging from 21°to 36°C. The humidity ranges from 71 to 89%. Teak is a common occurrence which is found in association with Macaranga peltata (Chandada), Mangifera indica (Wild mango), Garcinia (Kokum). Shrubs like Mussaenda frondosa (Dhobi tree), Ixora coccinea (Jungle geranium) are common along with orchids like Eria and climbers like Begonia spp. Seasonal wild balsams (Impatiens sp.), Sida rhombifolia (Arrow Leaf Sida), Sonerila rheedii (Rheed's Sonerila) and Melastoma malabathricum (Malabar Melastome) are abundant. As one moves to a higher elevation through dense foliage and small streams of cascading water, breath-taking glimpses of the vegetation and the landscape can be witnessed.

Methods
Spiders were visually searched in their microhabitats such as ground, litter, bushes, flowers, leaves, branches, in cracks and crevices. Webs and web lines were traced to locate the spiders. Logs and stones after being upturned to search for spiders were placed back in their original position. Spiders were photographed in their natural habitat itself as soon as they were sighted using Canon EOS 500D DSLR mounted with 18-55 mm lens attached with Raynox DCR-250 magnifying lens.
Random active search was employed to capture spiders.
Whenever possible, the spiders were handpicked. The lid-container method was used to trap the spiders. Vegetation beating was done using a wooden stick with an inverted umbrella placed below the vegetation to collect the spiders that were out of reach. Sweep net method was used to collect spiders that dwell in the foliage. The collected specimens were preserved in 70% alcohol. Spiders were examined under a stereozoom microscope (Weswox STM-80) and identified with the help of taxonomic keys and illustrations provided by Gajbe (2007Gajbe ( , 2008, Gravely (1921a,b, 1924, 1931) Pocock (1900, 1901), Tikader (1960, 1963, 1970, 1971, 1980, 1981, 1982a, Tikader & Bal (1981), Tikader & Malhotra (1980), Sethi & Tikader (1988), Proszynski (1992 and other relevant literature. Nomenclature and taxonomy is according to the World Spider Catalog (2020). All the specimens were identified up to family and generic level and some to specific level. Spiders that could not be identified are not included in the checklist.

Results and Discussion
The study at Chandranath Hill, Goa from June 2018 to March 2020 resulted in the documentation of 125 species belonging to 102 genera of 19 families (Table 1).
Spiders from family Salticidae proved to be the most dominant constituting 26.40% of the total species (33). Further, 22.40% of the species (28) belonged to Araneidae making it the second dominant family. The families with least number of species (01) were Cheiracanthiidae, Ctenidae, Gnaphosidae, Hersiliidae, Philodromidae and Scytodidae.

Guild structure
Six feeding guilds, namely, orb weavers, foliage runners, ground runners, stalkers, space-web builders, and ambushers were identified based on the foraging behaviour (Uetz et al. 1999).
Vegetation architecture plays a major role in the species composition found within a habitat (Greenstone     1984;Scheidler 1990;Sudhikumar et al. 2005) and vegetation which is structurally more complex can sustain higher abundance and diversity of spiders (Hatley & Macmahon 1980;Sudhikumar et al. 2005). Additionally, good vegetation along with floral diversity houses a number of insect species, this in turn results in hosting a high diversity of spiders as insects happen to be their main prey (Chetia & Kalita 2012).