• Korean Journal of Ecology and Environment
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• v.56 no.3
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• pp.250-258
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• 2023

Freshwater jellyfish, a type of jellyfish exclusively found in freshwater, has a limited number of species but is found globally. However, their ecology and causes of occurrence are largely unknown. Therefore, understanding the distribution of polyps, which produce the larvae of freshwater jellyfish, can provide important data for comprehending their ecology. This study aims to explore the COI gene of freshwater jellyfish using environmental DNA from the microbial film in the Miho River system. Among the 12 survey points in the Miho River watershed, genetic material of freshwater jellyfish was detected in 8 points, mainly located upstream near reservoirs. These genetic materials were identified as genes of the well-known freshwater jellyfish species, Craspedacusta sowerbii. Notably, the C. sowerbii genes found in the Miho River watershed survey points were closely related to a species previously discovered in Italy. Consequently, utilizing environmental DNA to explore the genetic traces of freshwater jellyfish enables rapid screening of areas with a high likelihood of freshwater jellyfish occurrence. This approach is deemed to provide crucial information for understanding the distribution and ecology of freshwater jellyfish in Korea.

• Animal cells and systems
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• v.2 no.3
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• pp.303-308
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• 1998

Freshwater jellyfishes were collected from Taechong Dam reservoir in Korea on September 1994. Tiny nontentacled hydroids were also collected from Taechong Dam and Chuam Dam reservoirs in Korea between September 1995 to September 1997. The medusae were identified into Craspedacusta sowerbii Lankester, 1880 and tiny hydroids were found to be in its polyp stages. It belongs to the family 0lindiidae in Limnomedusae and is first recorded from Korea. Environmental factors affecting the medusa occurrence are discussed.