Cyphonautes larvae are confirmed for the first time among the temperate freshwater zooplankton. They are part of the life cycle of the ctenostome bryozoan, Hislopia prolixa Hirose and Mawatari, 2011, known so far from China, Japan, and the Republic of Korea. Until 2008 cyphonautes were thought to be exclusively marine, occurring in three families of ancient ctenostome and cheilostome bryozoans. Since then they have been recognized in several tropical freshwater bryozoan species of the Genus Hislopia. Their presence in temperate latitudes now enlarges the area where these unusual larvae can be studied in their natural habitat. Embryological development in fresh water can be easily observed from egg to larva within a span of 12-24 h. Laboratory culture of the larvae has so far been hampered by their small size, hydrophobic body surface, unknown nutritional requirements, and high mortality rate.
A newly recorded species Orchomenella pinguis (Boeck, 1861) belonging to the family Tryphosidae Lowry and Stoddart, 1997 has been collected from the east sea of Korea. The species is similar to O. minuta (Krøyer, 1846) and O. pinguides Walker, 1903 but, distinguishable with the following characteristics: gnathopod 1, propodus slightly narrowing distally; gnathopod 1, carpus with narrowly developed posterior lobe; gnathopod 2, carpus conspicuously swollen posteriorly; coxae 5-6, posterodistal lobes strongly produced; epimera 2-3, irregularly serrated posteriorly. The species is described and fully illustrated in this study. A key to the Korean species of Orchomenella is also provided.
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.
The genus Dorylaimoides Thorne and Swanger, 1936 comprises over 70 species and predominantly inhabits soil; however, some species are found in semiaquatic or aquatic habitats. In this study, D. elegans (de Man, 1880) Thorne and Swanger, 1936 and D. limnophilus (de Man, 1880) Loof, 1964, collected from sediments in the Hangang River, are reported for the first time in Korea. These two Dorylaimoides species are distinguished from other Dorylaimoides species by their morphological characteristics: a didelphicamphidelphic reproductive system, short tail, and digitate terminus in D. elegans and a monoopisthodelphic reproductive system and long tail in D. limnophilus. Here, we provide detailed information on the morphological characteristic (description and illustration) and morphometrics of the two Dorylaimoides species, using optical microscopy. Additionally, 18S rDNA sequences of the two species from the Korean isolates are provided as molecular evidence.
