Biodiversity Journal, 2020, 11 (2): 593–610 https://doi.org/10.31396/Biodiv.Jour.2020.11.2.593.610 Species diversity of Spiders (Araneae) in Mimbilisan Pro- tected Landscape, Misamis Oriental, Philippines Inamol Hassan G. Lucman1, Olga M. Nuñeza1* & Aimee Lynn B. Dupo2 1Department of Biological Sciences, College of Science and Mathematics and Premier Research Institute of Science and Mathe- matics, MSU-Iligan Institute of Technology, Iligan City, Philippines. 2Department of Biology, University of the Philippines, Los Banos, Museum of Natural History, Pedro R. Sandoval Ave, Los Baños, Laguna, Philippines. *Corresponding author, email: [email protected] ABSTRACT Spiders have a potential role as bioindicator of ecological health. Yet, little is known about them especially in forested areas of the Philippines. This study determined the species di- versity of spiders in three different sampling sites established in Mt. Mimbilisan Protected Landscape. A combination of beat-netting and vial-tapping methods was used to collect sam- ples. One hundred eight species of spiders belonging to 17 families were recorded. Fifteen species are a new record to the Philippines. Highest species richness and abundance were ob- served in the riparian forest (Site 2) and lowest in the mixed dipterocarp forest (Site 1). Salti- cidae is the spider family with the highest species richness and abundance. Opadometa fastigata of family Tetragnithidae was the most abundant species. A great number of adult spiders (82.42%), which were mostly females (88.00%), was documented. Even distribution (E=0.7676) was recorded in the whole study area. Leaf surfaces and branches or stem of plants were the most recurring microhabitat types of spiders. The spiders were found to belong to seven guilds with the orb weavers as the most dominant guild (37%). The highest diversity was recorded in Site 2 (H’=3.781). Results indicate high spider diversity in Mt. Mimbilisan which highlights the conservation importance of the protected landscape. KEY WORDS Araneidae; conservation; forest; orb-weavers; Salticidae. Received 12.03.2020; accepted 20.05.2020; published online 30.06.2020 INTRODUCTION 2012). They can be found all around except in air and water (Foelix, 2011), from trees, under stones Spiders belong to a special group of inverte- and logs, in garbage, and on the forest floor brates comprising the largest order Araneae. They (Mathew et al., 2009). are sensitive to environmental changes and influ- Spiders are considered as an important group ence neighboring populations. They are abundant from both an economic standpoint in their use as bi- and diverse in nature (Wilder, 2011). They encom- ological control agent and in their diversity and pass the class Arachnida that utilizes a wide range adaptation to a number of differing habitats (Maha- of niches (Puja, 2014). Spiders are a mega-diverse lakshmi & Jeyaparuathi, 2014). They respond group comprising 47,445 described species (World rapidly to alterations in environment and thus, used Spider Catalog, 2018) and are considered as the as indicators of ecological change (Hodge & Vink, seventh most diverse order worldwide (Cardoso, 2010). They serve as limiting factors in the increase 594 INAMOL HASSAN G. LUCMAN ET ALII of pest populations in different ecosystems through et al., 2015), Marilog District, Davao City (Patiño their predatory behavior (Sharma, 2014). Spider et al., 2016), Sacred Mountain in Marawi City silk nowadays is used to make bullet proof vest, (Juario et al., 2016), Imbayao, Bukidnon (Mondejar parachutes, surgical threads, artificial tendons, and & Nuñeza, 2016), and caves in Mindanao (Enriquez even biodegradable bottles (Hinman et al., 2003). & Nuñeza, 2014). Venom of spiders is being studied in the field of Of the remaining forest in the country, 26% can medicine (Clarke, 2002). only be found in protected areas (Ong, 2002). Mim- According to Chen & Tso (2004), a lot of sci- bilisan Protected Landscape is among the 240 pro- entific studies on spiders were conducted in tem- tected landscape areas of the Philippines. However, perate regions while tropical areas have relatively there is no spider fauna data in this protected land- less investigation. Species richness and their rela- scape and thus, this research is significant as this tive abundance help in describing spider commu- will provide baseline data of spider fauna and will nities (Sorensen et al., 2002). Without being indicate the present ecological health status of affected by their high diversity and ubiquity, large Mimbilisan Protected Landscape. It will also con- quantities of species have restricted distribution tribute to the existing studies on spiders in the and biogeographic patterns of assemblages (Car- Philippines especially on the island of Mindanao. valho et al., 2011). Royauté & Buddle (2012) re- The study aimed to determine species diversity, ported that in agricultural fields, there are guild structure, and microhabitats of spiders in evidences that synchronization with habitat Mimbilisan Protected Landscape. changes and disturbances are present in species that are dominant. Areas near or with human settle- ments in Brazil have higher spider diversity indices MATERIAL AND METHODS and evenness values when compared to undis- turbed areas (Freitas et al., 2013). Environment al- Study area terations may affect their distribution and assemblages by variations of plant community Based on the IUCN Protected Area Manage- structure, disturbance, and abiotic factors (Juario ment Category System, Mimbilisan Protected et al., 2016). According to Hore & Uniyal (2009), Landscape (Figs. 1-3) belongs to Category 5, areas spiders are utilized as bioindicators for evaluating that are managed for landscape conservation or the impact of anthropogenic disturbances on natu- recreation. It serves as a watershed that provides ral ecosystems. They face an exceptionally high water to its nearby communities. It is composed of risk of extinction (Thomas et al., 2004) caused by mixed dipterocarp forest that covers 66.515 human disturbance and climate change. hectares in Brgy. Mapua, municipality of Balin- The Philippines, a tropical country, is among the gaoan, Misamis Oriental. Mimbilisan Protected 17 mega diverse countries which constitutes 70- Landscape is located at 8.94617 latitude; 124.8676 80% of the world’s biodiversity. For many parts of longitude. The Mindocdocan Creek can be found at the Philippines, little is known of the arthropod its base. In some areas outside of the protected area, fauna. One of the most diverse groups of organisms agricultural activity was observed. in the Philippines is the spiders (Wankhade et al., 2012) consisting of about 517 species belonging to Sampling sites 225 genera and 38 families. Studies on spiders in the country are limited only to agricultural areas, Three sites in Mimbilisan Protected Landscape particularly rice fields, but they have the highest were sampled for 10 days for a total of 186 work record in all of Asia’s tropical rice fields (Workman, hours. The sampling sites were selected based on 1896; Barrion & Litsinger, 1995; Barrion, 2001). In the following criteria: accessibility, habitat struc- Mindanao, the second largest island in the Philip- ture, degree of exposure to human activities, and pines, recent studies on spiders were reported in Pu- geographical position. Disturbances in the sam- lacan falls, Zamboanga del Sur (Dacanay et al., pling sites were qualitatively categorized as low, in- 2014), Mt. Matutum, South Cotabato (Garciano et termediate, or high based on the accessibility, al., 2014), Mt. Pinukis, Zamboanga del Sur (Lalisan presence of facilities, and presence of human dis- Species diversity of Spiders in Mimbilisan Protected Landscape, Misamis Oriental, Philippines 595 Figure 1. Map of Australasia and central-southern Philippines (Maphill, 2018). Figure 2. Map of northern Mindanao (Maphill, 2018). Figure 3. Location of the study area (BMB-DENR, 2015). turbance. Transect lines were established along and thus high disturbance, mainly human-made, trails due to the gorge shape of the mountain. can be observed in the site. Sampling site 1 is a mixed dipterocarp forest Sampling site 2 is a riparian forest with coor- with coordinates of 8°56.820’N, 124°52.042’E. Its dinates of 8°56.834’ N and 124°52.124’ E. Its ele- elevation ranges from 415–465 meters above sea vation ranged from 350–450 m a.s.l. The site has level. The site has a mountainous slope and sec- an undulating slope and covered with secondary ondary vegetation type. Sunlight cannot easily vegetation. A freshwater stream with shallow pools penetrate through the ground due to the presence of water serves as a faunal corridor, connecting of high density of emergent and canopy trees. Sites 1 and 3. The site was dry, revealing large Emergent trees were Shorea sp. whereas canopy rocks due to the diversion of water for the water trees include Shorea negrosensis, S. contorta, Pte- system of the people in the locality. Rocks were rocarpus indicus, Swietenia mahogany, Dracon- mainly covered with Bryophyta sp., especially near tomelon dao, Artocarpus sericicarpus, and Ficus pools of water. The emergent tree was Shorea sp. gul. Understory plants include the family Are- while canopy trees were Dracontomelon dao, caceae, Costus igneus, and Caryota mitis. Most of Bosscheria minahassae, and Artocarpus odoratis- the ground cover plants were Schismatoglottis ca- simus. The canopy epiphytes present include moss, lyptrata and ferns. Leaf litter depth measures about vines, and ferns. Fruit-bearing tree taxa include 2 cm. The covering canopy trees have epiphytes Lansium parasiticum, Averrhoa carambola, and such as ferns and vines coiling in their trunks. Or- Artocarpus odoratissimus. Ferns, grasses, and chids were also observed. Site 1 has a clay soil sedges were rarely observed. Other plants include where exposed rocks and few fallen logs were pre- bamboo, Ficus benjamina, Pandanus yvanii, sent which may have been caused by a storm. A Cheilocostus speciosus, Poikilospermum suave- freshwater stream was located 100 m away. Its dis- olens, Clerodendrum paniculatum, Alocasia prin- tance to anthropogenic clearing was 450 m. Rub- ceps, and Aglaonema nitidum.