Spider Fauna on Ulleungdo Island in Korea

The present study was conducted to establish a comprehensive checklist of spiders on Ulleungdo Island in Korea. Past records were compiled and four new surveys of spiders in Ulleungdo Island were conducted from May to September 2019. The surveys were conducted at 18 sites in seven of the nine major administrative districts. A total of 114 species from 84 genera in 26 families were identified from 958 individual spiders. The 21 spider species belonging to 10 families were added to the known spider fauna on Ulleungdo Island from the present study. The survey results were combined present results with previous records showed there were 242 species from 143 genera in 32 families on Ulleungdo Island. The species richness in each family was high, in the order Araneidae, Theridiidae, Salticidae, Linyphiidae, Tetragnathidae, Thomisidae, Gnaphodidae and Philodromidae. Four Korean endemic species, Coscinida ulleungensis Paik, 1995, Steatoda ulleungensis Paik, 1995, Drassodes taehadongensis Paik, 1995 and Phrurolithus pennatoides Seo, 2018, found only on Ulleungdo Island. In addition, the following six indigenous species that inhabit only in Ulleungdo Island: Euryopis octomaculata (Paik, 1995), Porrhomma montanum Jackson, 1913, Piratula knorri (Scopoli, 1763), Cladothela parva Kamura, 1991, Cladothela unciinsignita (Bösenberg and Strand, 1906) and Clubiona tongdaoensis Zhang, Yin, Bao and Kim, 1997. The zoogeographical distribution of spiders on Ulleungdo Island was classified into 9 cosmopolitan species (3.7%), 16 holarctic species (6.6%), 23 palearctic species (9.5%) and 6 Korean endemic species (2.4%). Fauna checklists are used to aid the assessment of biodiversity at various scales and are beneficial for the effective long-term management and use of national biological resources. The present study provides meaningful information for understanding national biodiversity.