Survey of Land Snails (Class Gastropoda) in Sitio Siok Koronadal, Southern Mindanao, Philippines

Sitio Siok, situated in Barangay Mabini, City of Koronadal, South Cotabato located along the Roxas Mountain Ranges in Mindanao Island, Philippines, features rivers and numerous waterfalls that contribute to the area's moisture. In 2014, certain parts of this tropical rainforest-climate mountain were converted into an eco-tourism attraction and nver trekking site, Unfortunately, this development poses a threat to the diverse malacofauna, particularly land snails, which struggle to escape habitat degradation. To address this concern, an assessment of the land snail diversity in Sitio Siok on December 26-27, 2023 were conducted. The research involved surveying three Quadrats measuring 10 * 10 meters, each at least 50 meters apart, using a soil-leaf litter and timed search method The study collected 1,337 individuals across all three Quadrats comprised of eight species that were classified under two orders, Architaenioglossa and Stylommatophora, and four families: specifically, three species from Cyclophoridae (Cyclophorus linguiferus, Leptopoma perlucidum, Cyclotus sp.), one species from Pupinidae (Pupina sp.), two species from Ariophantidae (Macrochlamys spl., Macrochlamys sp2.), and two species from the family Diapheridae (Diaphera spl., Diaphera sp2), all species are native. The most abundant species was Cyclophorus linguiferus, with a total of 1,230 individuals and a relative abundance of 92%. It was followed by Macrochlamys sp2, with 41 individuals and a relative abundance of 3.07%. The calculated biodiversity indices were as follows: Shannon index (H') = 0.396 Simpson Index (D) = 0.85, and Pielou's Evenness (J') = 0.19 The dominance of Cyclophorus linguiferus could potentially explain the low species richness and diversity observed in Sitio Siok, in addition to abiotic factors and habitat degradation. This study serves as a baseline for understanding land snail diversity and provides valuable insights into the malacofaunal structure of Sitio Siok, which can be utilized for future assessments and the development of efficient conservation initiatives.