• Journal of Species Research
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• v.5 no.3
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• pp.381-384
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• 2016

Two marine amoebae Vannella bursella (Page, 1974) Smirnov et al., 2007 and Pseudoparamoeba sp. were encountered from marine coastal waters of Masan Bay and Garorim Bay (Korea), respectively. These species are described with uninterpreted records based on light-microscopy of living cells and reported taxonomically for the first time from Korea. Diagnostics of these species are as follows. Vannella bursella: size in vivo, $17-29{\mu}m$ long with flattened ovoid, semicircular locomotive forms. Pseudoparamoeba sp.: size in vivo, $10-15{\mu}m$ long with elongated locomotive forms, producing a few short conical pseudopodia from anterior hyaline zone.

• Parasites, Hosts and Diseases
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• v.62 no.2
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• pp.180-192
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• 2024

Free-living amoebae (FLA) are found in diverse environments, such as soils, rivers, and seas. Hence, they can be used as bioindicators to assess the water quality based solely on their presence. In this study, we determined the presence of FLA in river water by filtering water samples collected from various sites and culturing the resulting filtrates. FLA were detected in all the water samples with varying quality grades (Grades I-V). The significant increase in the size of the amoebae population with the deterioration in the water quality. Monoxenic cultures of the amoebae were performed, and genomic DNAs were isolated, among which 18S rDNAs were sequenced to identify the amoeba species. Of the 12 species identified, 10 belonged to the Acanthamoeba genus; of the remaining 2 species, one was identified as Vannella croatica and the other as a species of Vermamoeba. Acanthamoeba was detected in samples with Grades I to VI quality, whereas the Vermamoeba species was present only in Grade I water. V. croatica was found exclusively in water with Grade II quality. Following morphological observations, genomic DNA was sequenced using 16S rDNA to determine whether the species of Acanthamoeba harbored endosymbionts. Most of the isolated Acanthamoeba contained endosymbionts, among which 4 species of endogenous bacteria were identified and examined using transmission electron microscopy. This study provides evidence that the distribution of amoebae other than Acanthamoeba may be associated with water quality. However, further confirmation will be required based on accurate water quality ratings and assessments using a more diverse range of FLA.