• ALGAE
• /
• v.34 no.2
• /
• pp.91-97
• /
• 2019

Chilean species of marine macroalgae with amphitropical distributions oftentimes result from introductions out of the Northern Hemisphere. This possibility was investigated using haplotype data in an amphitropical red macroalgae present in Chile, Callophyllis variegata. Published sequence records from Canada and the United States were supplemented with new collections from Chile (April 2014-November 2015). Specimens of C. variegata were amplified for the 5′ end of the cytochrome c oxidase subunit I gene (COI-5P) and the full length nuclear internal transcribed spacer region. Haplotype networks and biogeographic distributions were used to infer whether C. variegata was introduced between hemispheres, and several population parameters were estimated using IMa2 analyses. C. variegata displayed a natural amphitropical distribution, with an isolation time of approximately 938 ka between hemispheres. It is hypothesized that contemporary populations of C. variegata were established from a refugial population during the late Pleistocene, and may have crossed the tropics via rafting on buoyant species of kelp or along deep-water refugia coincident with global cooling, representing a rare case of a non-human mediated amphitropical distribution.

• Parasites, Hosts and Diseases
• /
• v.59 no.1
• /
• pp.89-95
• /
• 2021

Microcotyle sebastis is a gill monogenean ectoparasite that causes serious problems in the mariculture of the Korean rockfish, Sebastes schlegelii. In this study, we isolated the parasite from fish farms along the coasts of Tongyeong, South Korea in 2016, and characterized its infection, morphology and molecular phylogeny. The prevalence of M. sebastis infection during the study period ranged from 46.7% to 96.7%, and the mean intensity was 2.3 to 31.4 ind./fish, indicating that the fish was constantly exposed to parasitic infections throughout the year. Morphological observations under light and scanning electron microscopes of the M. sebastis isolates in this study showed the typical characteristics of the anterior prohaptor and posterior opisthaptor of monogenean parasites. In phylogenetic trees reconstructed using the nuclear 28S ribosomal RNA gene and the mitochondrial cytochrome c oxidase I gene (cox1), they consistently clustered together with their congeneric species, and showed the closest phylogenetic relationships to M. caudata and M. kasago in the cox1 tree.

• Fisheries and Aquatic Sciences
• /
• v.24 no.6
• /
• pp.228-234
• /
• 2021

A single specimen (39.4 mm standard length) of Brachaluteres ulvarum, belonging to the family Monacanthidae has been recorded for the first time from Supseom, Jeju-do Island of southern Korea on 6 March 2021. This species was characterized by the presence of a small second dorsal spine present, the posterior end of pelvic without encasing scales, and numerous thin dark longitudinal lines on body. It was morphologically similar to the B. taylori, but distinguished by the ratio of the caudal peduncle to the head length (B. ulvarum, 2.5 to 3.7 times; B. taylori, 3.5 to 5.2 times). In addition, the former is well distinguished from the latter through mitochondrial cytochrome c oxidase subunit I (COI) sequences by genetic distances of range from 0.088 to 0.090. The new Korean name "Kko-ma-jwi-chi- sog" is proposed for the genus Brachaluteres, and "Kko-ma-jwi-chi" for the species B. ulvarum.

• ALGAE
• /
• v.36 no.1
• /
• pp.13-24
• /
• 2021

The present-day genetic structure of macroalgal species reflects both geographical history and oceanic circulation patterns as well as anthropogenic introduction across native ranges. To precisely understand the genetic diversity and how the factors shape the current population structure of Gloiopeltis furcata sensu lato, we determined the mitochondrial 5' end of cytochrome c oxidase subunit I (COI-5P) sequences for 677 individuals sampled from 67 sites spanning almost the entire distribution range in Korea and Japan. Results from the phylogenetic analysis and haplotype distribution revealed eleven distinct lineages within G. furcata s.l. along the Korea-Japan coastal areas and displayed divergent phylogeographic patterns among lineages. Despite the closely related lineages distributed in same habitats as high rocky intertidal zone, they display different phylogeographic patterns among lineages. The populations from the south of Korea-Japan harbored the highest genetic diversity and unique endemism in comparison with other populations in the distribution range. This could be the evidence of southern refugia for G. furcata s.l. in the Northwest (NW) Pacific and the recent migration from native to introduced region. The reason is that an exceptional distribution pattern was found high genetic diversity in Hakodate of Japan where is the northern location in the NW Pacific. Our results imply the contemporary influence on the distribution due to current circulation pattern and anthropogenic effects. These phylogeographic findings provide the important insight into cryptic species diversity and the detailed distribution pattern of Gloiopeltis in the NW Pacific.

• Parasites, Hosts and Diseases
• /
• v.60 no.4
• /
• pp.273-279
• /
• 2022

Laelapinae mites are involved in transmission of microbial diseases between wildlife and humans, with an impact on public health. In this study, 5 mite members in the subfamily Laelapinae (laelapin mites; LM) were morphologically identified by light microscopy, and the phylogenetic relationship of LM was analyzed in combination with the sequence information of part of the LM cytochrome oxidase subunit I (cox1) gene. The morphological identification revealed that 5 mites belonged to the genera Laelaps and Haemolaelaps, respectively. Sequence analysis showed that the ratio of nonsynonymous mutation rate to synonymous mutation rate of LM was less than 1, indicating that the LM cox1 gene had undergone purifying selection. Phylogenetic analysis showed that the Laelapinae is a monophyletic group. The genera Haemolaelaps and Hyperlaelaps did not separated into distinct clades but clustered together with species of the genus Laelaps. Our morphological and molecular analyses to describe the phylogenetic relationships among different genera and species of Laelapinae provide a reference for the improvement and revision of the LM taxonomy system.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.2
• /
• pp.146-153
• /
• 2022

The vertical distribution and abundance of icthyoplankton in the southern waters of Jeju Island during June 2020 were investigated. Fish eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and the 16S rRNA gene. During this period, fish eggs of 23 taxa belonging to 21 families and larvae of 27 taxa belonging to 25 families were collected. Fish eggs were located mostly from the surface to 30 m depth of the water column. Larvae were located from the surface to 80 m depth of the water column. Vertical distributions of fish eggs and larvae were influenced by oceanography conditions such as temperature, salinity, and thermocline depth. No discernible difference in mean thermocline depth was observed between day and night.

• Fisheries and Aquatic Sciences
• /
• v.25 no.9
• /
• pp.489-497
• /
• 2022

The first specimen (54.8 mm standard length) of Ernogrammus zhirmunskii Markevich & Kharin, 2011, belonging to the family Stichaeidae, was recorded in Dokdo, East Sea, Korea on July 26, 2021. This species was characterized by a single ventral lateral-line canal from the posterior margin of the pelvic-fin base extending to the anus and one or two rigid spines on the posterior part of the anal fin. This species is similar to Ernogrammus hexagrammus and Ernogrammus walkeri but differs in the number of ventral lateral-line canal present, with E. zhirmunskii consisting of one (unpaired) ventral lateral-line canal compared to other two Ernogrammus species, which have a pair of parallel ventral lateral-line canal. For further analysis of species identification, a partial gene sequence from the mitochondrial DNA cytochrome oxidase subunit I (554 bp) of E. zhirmunskii was obtained for the first time. This study documents the first record of E. zhirmunskii in Korean waters and proposes the new Korean name of 'Il-gob-julbe-do-la-chi' for the species.

• Journal of Veterinary Science
• /
• v.21 no.6
• /
• pp.86.1-86.8
• /
• 2020

Background: Dicyemids are parasites found in the renal sac of cephalopods. The first species of dicyemid was found from kidneys of the Korean common octopus Callistoctopus minor. Objectives: This study aimed to identify the dicyemid and investigate the effect on renal sac of host. Methods: In this study, we compared the morphological characteristics of isolate to dicyemids (Dicyema sphyrocephalum, Dicyema clavatum, and Dicyema dolichocephalum) reported from C. minor in Japan. We compared the 18S ribosomal RNA (rDNA) and cytochrome c oxidase subunit I (COI) sequences of isolate to the sequences of D. shyrocephalum and D. clavatum. The infected octopuses renal tissues were histologically compared with the tissues of uninfected individuals. Results: The morphological characteristic of this isolated species corresponds to D. sphyrocephalum. The sequences similarities of 18S rDNA and COI gene of isolate are 99.7% and 98.1% with D. sphyrocephalum. We observed morphological changes in the epithelia folds of kidney at the dicyemids attached areas. Conclusions: The present study identified the isolate as D. sphyrocephalum and this is the first report of dicyemid species from Republic of Korea. Further studies on the effects of dicyemids on growth and health status of cephalopods will be needed.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.3 no.4
• /
• pp.221-226
• /
• 2022

A filarial nematode was found in a blood sample of an Anas falcata individual collected in South Korea in 2018. Phylogenetic analysis based on partial cytochrome C oxidase subunit I (COI) sequences placed the nematode as a novel genus of the family Onchocercidae and as closely related to Mansonella species, Chandlerella quiscali, and filarial nematodes recently reported in avian species. However, different phylogenetic relationship was observed in the NADH dehydrogenase subunit 5 and 12S rRNA-based phylogenetic trees, which might indicate the filarial nematode found in this study was not defined to belong to the known specific genera of the family Onchocercidae. The screening of 105 additional avian blood samples retrieved only one 12S rRNA-targeting polymerase chain reaction (PCR)-positive sample, which indicates that filarial nematode infection is rare in wild birds or that it occurs below the detection limit of PCR in blood samples. Nevertheless, considering the recent findings about ancient interactions between birds and human pathogenic filarial nematodes and their pathogenic potential in several avian species, additional exploration of novel filarial nematodes in wild birds remains necessary.

• Parasites, Hosts and Diseases
• /
• v.60 no.3
• /
• pp.201-205
• /
• 2022

Babesia microti is one of the most common causative agents of babesiosis. A sensitive and rapid detection is necessary for screening potentially infected individuals. In this study, B. microti cytochrome c oxidase subunit I (cox1) was selected as the target gene, multiple primers were designed, and optimized by a recombinase-aided amplification (RAA) assay. The optimal primers and probe were labeled with fluorescein. The sensitivity of fluorescent RAA (fRAA) was evaluated using gradient diluents of the cox1 recombinant plasmid and genomic DNA extracted from whole blood of B. microti infected mice. The specificity of fRAA was assessed by other transfusion transmitted parasites. The analytical sensitivity of the fRAA assay was 10 copies of recombinant plasmid per reaction and 10 fg/µl B. microti genomic DNA. No cross-reaction with any other blood-transmitted parasites was observed. Our results demonstrated that the fRAA assay would be rapid, sensitive, and specific for the detection of B. microti.