Getting more pieces of Mosaics on West Sumatran Spiders (Araneidae): Inventory from Mount Marapi in West Sumatra

The field survey had been regulated from September until December 2019 by deploying an array of hand collection, sieving, sweeping and beating techniques applied simultaneously along three pairs of 120 m transect positioned at both sides of mountain hiking tracks. This exploration aimed to survey and inquiry the diversity of spiders (Araneidae) in Mount Marapi, West Sumatra Province. There were 25 spider individuals collected in this study; they were then identified and classified into 15 species which associated with 8 genera. Gasteracatha was a genus with the most species found (3 species, 9 individual), followed by Argiope (3 species, 7 individual) and Cyclosa (3 species, 5 individuals). Without minimizing the role of other collecting techniques, the hand collection technique was seemed to be more effective in doing the inventory on either spider individuals or species than the beating, sweeping or sieving techniques. The latter technique yielded the least result in this study.


Introduction
Araneae spiders are special group of invertebrates that use a wide variety of niches in ecosystem [1] and have a dominant role in the ecosystem with a variety of body, shapes, eye patterns, wonderful hues, habits strategy and approach [2] and foraging structures they perform numerous ecological services that assist in natural conquering of many insect gadfly [3].Presently, 39,882 species of spiders associated with 3676 genera and 108 families have been globally described [4] Nevertheless, 170,000 species of these arachnids are approximate to survive in the globe, which review the meagre of studies about this group of animals [5].Spider diversity in the variable zones has been well studied, but the tropics are relatively poorly studied [6].Indonesia is one of the tropical countries which is represented only by 517 spider species, belonging to 225 genera and 38 families [4,7 ].
Previous studies about spiders had been conducted by the researcher in several islands in Indonesia, Spider fauna from Sumatra had been studied [5,7,8] and four new species of armoured spiders (Araneae, Tetrablemmidae) from Sumatra had been reported, The female of Ablemma singalang Lehtinen, 1981 is described here for the first time [7].New species (Linyphiid) differs from its congeners by structural details of the genitalia had found in Jambi, Sumatra [8].Three new genera and four new species are described from Java, Indonesia [9], they were Javagone maribaya, Walckenaeria caobangensi and Parameione tasulawesi.Though, Research on arachnids on mountain field is limited.This exploration aimed to survey and inquiry the diversity of spiders

Study Site and Sampling Method
Sampling was conducted in Mt.Marapi (7058'31"N and 123013'43" E), located in Agam Regency, West Sumatra, It has an altitude of 2,893 asl.Hand colection, sieving, beating, and sweeping were used for sampling the spider in this study, hand collection (by hand) for meandering and hunting spiders rushing on trunks, leaves and leaf litter.Mygalomorph spiders, which make tubular webs and/or live in burrows; Sieving used for trapping spiders living in leaf litter and burrows and minute spiders burrowed in the first layer of the soil; Beating for ambushing species on higher vegetation and flowers, and orbweb weaving spiders and entangled web weaving spiders dwelling in branches and higher vegetation.Sweeping for collecting spider on low vegetation, ambushing on flowers, and young web weaving spiders in low vegetation and bar [10].

Collection, Processing, and Identification of Samples
Species Sampling was executed every morning from 9.00 am to 12.00 pm and in the late afternoon from 2.00 pm to 6.00 pm.120-meter transect line was defined equally in each range.Bushes, tree trunks, ferns, forest floor, leaves, meadows were entirely explored for spiders and collected by a combination of expedience sampling hand collection, sweeping, beating and sieving methods.Collected samples were placed in large containers to aid depot as they are highly locomotive.The spider was temporarily placed in a zip-lock plastic pack for live photography.The specimen were then stored in glass vials with a 70% alcohol solution glass vials labelled with the date of collection in the field for later identification.Spider in Brunei Darussalam and Spider in Southeast rain forest book were used to recognize entire sample.

Data Analysis
The Spiders were sorted, photographed and identified at Laboratory of Taxonomy, Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Andalas, West Sumatra, Indonesia.Identification relied on morphological characters according to Spider in Brunei Darussalam and World spider Catalog [4,18].The data was tabulated with specific concerns given to species inventory and their distribution across sites.The results were then thoroughly discussed.

Results and Discussion
Araneids representing eight genera and 15 species were assembled and recognized from three sites of Mt.Marapi through the survey (Table 1).This number is higher compared than other spiders recorded in West Sumatra found nine species belonging to six genera [10].Gasteracantha with three species from nine individuals, Argiope with three species from nine individuals and Cylcosa with three species from five individuals were the dominant genus (Table 1).The observation that Argiope is abundant conforms with the findings of spiders in the tropical area [4] Cyclosa and Argiope prefer sites strongly affected by the presence of vegetation, as well as near water systems, shady vegetation, trunk trails, tree trunks or buttresses, and woody debris.[5].Argiope spiders are most commonly found on plant leaves and canopies, where they act as pioneer or stabilizing posts in web construction [3,6,7,].
The sternum of Gasteracantha is brownish-black with a large yellow spot in the center.The abdomen is much wider than long.Two black and three white horizontal bands found in Dorsa side of abdomen.Two black abdominal horizontal bands curved with sinuous margins.The first black horizontal band is slightly hollow at the anterior middle.Edge of the abdomen has serrated spikes, obvious on spines.Anterior spines smallest, directed obliquely.Posterior spines conical, pointed backward.Median spines are longest, less conical, and slightly arched backward.Gasteracantha was the most abundant genus comprising 26.4 % of the total individual collected.All species were assembled with all techniques sampling that used in this study with horticulture and hedge are Subsistence.Yadav et al. (2012) described that gasteracantha was found in low shrubs and grasses in shaded and moist environments.Regularly found in mixed deciduous forest and dipterocarp forest.Spiders usually build vertical webs between shrubs in open areas and stay in the middle of the webs [7] Argiope spiders accounted for 20.5% of all individuals earned.The genus Argiope (Araneidae, Orbweaver) has a cosmopolitan distribution, exhibits characteristic sexual dimorphism, and defined by colorful females with offbeat web decorations.[8].The genus is currently comprised of 88 taxonomically accepted species [4].Argiope taxonomy is well documented correspondent to Levi's expanded research (1983; 2004), and Bjorn (1997) [4].Confirming the use of broken emboli in female specimens as a useful method for identifying Argiope species [9] This impressive study has enabled numerous research studies on this genus, including species descriptions and synonyms, molecular and biogeographical analyses [10,11,12,13,14].Three of specimen Argiope was regognize in the present study based on illustration of their morphology.Argiope sp. 3 was the highest number of individuals in this genus (four individuals).This species resembles the Argiope chloreides Chrysanthus 1961 in its small size (~6 cm in length) and green coloration.Square epigin in posterior view with thin white rim of dorsal opistosome without trapezoidal markings, relatively thick septum and rim, larger pit, and well-developed posterior lip extending laterally from the posterior plate.
The spider genus Cyclosa Menge, 1866 currently includes 179 species worldwide [4].Members of this genus can be found on almost all continents, except Antarctica.Nineteen species are known from the Indian subcontinent [15].Species known from Indonesia were two species, Cyclosa caligata (Java) and Cyclosa seriata (Sumatra) [4].Blackish-brown with reddish-orange tinge midventally and laterally, covered with white hairs, rounded apically, broadest medially.Clycosa sp.2 bears resemblance to Clycosa bifida by The back has a central silvery-white spot and 3 pairs of translucent brownish sigils laterally.The venter is brownish-black with fine brown on the medial and posterolateral sides but lacks shiny white hairs.Clycosa bifida has shiny white hairs [16].Two individuals of Clycosa sp.1 and Clycosa sp.3 were found in each species.Clycosa sp.1 has a brownish-black belly, an elongated oval shape and a narrow front.Spine with central silvery white spot and four pairs of distinct brownish sigils in lateral rows.The sternum is well discouraged between Coxae and Clycosa sp.3, and the abdomen has a pair of anterior ridges and no caudal ridges.The shaft is wide with a distinct central bulge on the underside.The mating gait is almost straight Two species belonging to five individuals have been found in the spider genus Acusilas.Acusilas Simon, 1895, known as a small genus of orb-weaving spiders in the family Araneidae.It is mainly distributed in Asia, but also contains a single species from Africa [17].The species are medium to small and, in species known to have webs, build regular vertical globular webs containing centrally rolled lobes [18].Genus acusilas sp.One with a triangular abdomen.It is truncated in front and tapered in the back, the abdominal foil is white with black crossbars and orange in fresh specimens.
The spider genus Neogea, Neoscona and Eriovixia were found two individuals in Mt.Marapi.Neogeids had three species worldwide and one species was known record in Indonesia Neogea Noctocolor, Thore ll 1887.The species were found in this study is Neogea sp.With morphological character carapace is sparsely pubescent with very fine hairs.Comparatively long hairs present near the eyes.Cephalic region narrowed in front, slightly elevated and well demarked from thoracic part.Thoracic foevea and thoracic groove prominent [4, 7,9].

Conclusion
Inventory araneida from Mt. Marapi was conducted in September 2019 and had found 15 species belonging to eight genera.Gasteracantha and Argiope were the genera that found by all sampling techniques.

Figure 2 .
Figure 2. Representative species of araneidae found in Mt.Marapi West Sumatra Gasteracantha sp.1 and Argiope sp.1 as representative species form one of most highest number of individual genus; Herennia multipuncta as one of species that collected by hand collection method .