Habitat use of loggerhead (Caretta caretta) and green (Chelonia mydas) turtles at the northern limit of their distribution range of the Northwest Pacific Ocean

Verifying habitats, including the foraging and nesting areas for sea turtles, enables an understanding of their spatial ecology and successful planning of their conservation and management strategies. Recently, the observation frequency and bycatch of loggerhead (Caretta caretta) and green (Chelonia mydas) turtles have increased in the northern limit of their distribution range, in the northern part of the East China Sea and East (Japan) Sea. We conducted satellite tracking to investigate the habitat use of seven loggerhead and eight green turtles from June 2016 to August 2022 in this area, where little is known about their spatial ecology. We applied a 50 percent volume contour method to determine their main foraging areas and analyzed 6 environmental variables to characterize their habitats. Loggerhead turtles mainly stayed in and used the East China Sea as a foraging area during the tracking period, while two individuals among them also used the East Sea as a seasonal foraging area. Most green turtles also used the East China Sea as a foraging area, near South Korea and Japan, with one individual among them using the lower area of the East Sea as a seasonal foraging area. Notably, one green turtle traveled to Hainan Island in the South China Sea, a historical nesting area. Our results showed that the two sea turtle species included the East Sea as a seasonal foraging area, possibly owing to the abundance of food sources available, despite its relatively lower sea temperature. Considering that loggerhead and green sea turtles were observed using the northern part of the East China Sea and East Sea more frequently than previously known and that the sea temperature gradually increases due to climate change, conservation and management activities are required for sea turtles in these areas.

The complete mitochondrial genome of soft coral, Eleutherobia rubra (Brundin, 1896) (Cnidaria; Anthozoa; Malacalcyonacea; Alcyoniidae)

The mitogenome of a soft coral, Eleutherobia rubra (Brundin, 1896), was completely sequenced for the first time. The total mitogenome length of E. rubra is 18,724 bp with 14 protein-coding genes, two ribosomal RNA genes, one transfer RNA gene (tRNA-Met), and one non-coding region (NCR). The gene order is also consistent with other Alcyoniidae species. The base composition is 30.1% A, 16.7% C, 19.5% G, and 33.7% T, with a G-C content of 36.2%. This is the first record of the complete mitogenome sequence of the genus Eleutherobia.

Movement Patterns of Juvenile Loggerhead Turtles (Caretta caretta L. 1758) and Green Turtles (Chelonia mydas L. 1758) Hatched in Captivity and Released in the Korean Waters

With most sea turtle populations declining, activities to conserve their habitat and nesting grounds and restore their populations are being implemented worldwide. To preserve the Northwestern Pacific populations, the National Marine Biodiversity Institute of Korea has been releasing artificially propagated sea turtles, but whether these individuals join the wild population remains unknown. The present study aimed to determine the movement patterns of artificially propagated juvenile loggerhead (Caretta caretta) and green (Chelonia mydas) turtles fitted with satellite transmitters on their carapaces and released in the waters of Jeju or Yeosu, Republic of Korea, between August 2018 and April 2022. Loggerheads traveled northward to the East Sea, whereas green turtles moved west or southwest. Two 36-month-old and two 48-month-old loggerheads moved toward their potential nursery grounds and toward their feeding grounds, respectively. Three green turtles with a curved carapace length (CCL) of <40 cm moved toward their nursery or feeding grounds, while three individuals (CCL > 45 cm) moved toward their inshore foraging areas. The travel paths were closely related to the direction of local sea currents. Our results implied that releasing artificially propagated sea turtles, considering their age and CCL, can positively contribute to the conservation of Northwestern Pacific populations.

Association between Obesity and Anemia in a Nationally Representative Sample of South Korean Adolescents: A Cross-Sectional Study

Anemia is associated with physical, cognitive, and developmental problems. Given that there are limited studies on anemia prevalence among obese Asian adolescents and that past evidence is controversial, this study investigated the relationship between obesity and anemia in a nationally representative sample of South Korean adolescents. Data were obtained from the 2007–2019 Korea National Health and Nutrition Examination Survey. Overall, 10,231 subjects were included in the analysis. Multiple logistic regression was performed to determine the relationship between obesity and anemia. Compared with the non-obesity group, the adjusted odds ratio (OR; 95% confidence interval [CI]) of anemia was 1.00 (0.66–1.50) in the obesity group. However, in the early adolescent subgroup of 10–13 years (adjusted OR, 2.88; 95% CI, 1.20–6.95), the risk of anemia was significantly higher in the obese group than in the non-obese group. Obesity was associated with an increased risk of anemia in early adolescents. Obese adolescents aged 10–13 require special care, especially through regular examination and management for anemia.

Genetic analysis and population genetic structure of hard-shelled mussel, Mytilus coruscus Gould 1861 (Mytiloida: Mytilidae) from the coasts of South Korea based on mitochondrial cytochrome oxidase (COI) gene sequences

BACKGROUND

Mytilus coruscus Gould, 1861 is a mussel species in the family Mytilidae, native to the Northwest Pacific Ocean, ranging from the East China Sea, the Yellow Sea, and as far as the Peter the Great Gulf in the East Sea. In Korea, this species has been heavily exploited for nutrient-rich food resources and experienced severe reduction in their population.

OBJECTIVE

The aim of this study was to investigate the genetic diversity and population structure and to provide baseline data to facilitate the conservation and sustainable use of the vulnerable species M. coruscus in South Korea.

METHODS

Mitochondrial DNA (mtDNA) cytochrome c oxidase I (COI) sequences of 91 adult individuals from four islands and one coastal localities in South Korea were sequenced. We then compared genetic diversity and haplotype data with previously published Chinese wild populations.

RESULTS

Mytilus coruscus populations on Korean coasts were found to exhibit high genetic diversity despite concerns regarding recent population reduction. A total of 42 haplotypes were defined by 56 polymorphic sites. High-level genetic diversity was observed on four Island sites (Hd = 0.906-0.955, π = 0.0068-0.0090). The other seashore site represented relatively lower genetic diversity (Hd = 0.529, π = 0.0011) and was genetically differentiated from the others. In a previous study, wild populations on the East China Sea exhibited similarly high genetic diversity as that observed in our study. Additionally, Chinese M. coruscus populations exhibit a distinct regional haplotype distribution pattern while sharing six haplotypes with Korean populations.

CONCLUSIONS

The results of this study provide insights that further the current understanding regarding the evolution of M. coruscus species and provides comprehensive genetic data to facilitate the development of an effective conservation strategy.

The complete mitochondrial genome of a yellow-bellied sea snake (Hydrophis platurus) (Squamata, Elapidae)

In this study, we provide the first report of the complete mitochondrial genomic sequencing of a yellow-bellied sea snake (Hydrophis platurus) that has the broadest distribution range of all Squamata species. The mitogenome length was 18,101 bp and consisted of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 3 non-coding regions. The sequence presented could be very useful for further phylogenetic and evolutionary studies.

The complete mitochondrial genome of Montipora efflorescens (Scleractinia: Acroporidae)

The complete mitogenome of the Sclreractinia, Montipora efflorescens Bernard, 1897 was sequenced for the first time. It had 17,887 bp, with 13 protein-coding genes, and two rRNA and two tRNA genes. Composition of M. efflorescens mitogenome was identical to that of typical Scleractinians. In conclusion, the complete mitogenome may provide detailed information on coral phylogeny.

Complete mitochondrial genome of the Ijima's Sea Snake (Emydocephalus ijimae) (Squamata, Elapidae)

In this study, we provide the first report of the complete mitochondrial genome of Emydocephalus ijimae. The mitogenome length is 18,259 bp and includes 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and three non-coding regions. The sequence presented could be very useful for further phylogenetic and evolutionary study.

The complete mitochondrial genome of the sand-hopper Trinorchestia longiramus (Amphipoda: Talitridae)

The complete mitochondrial genome of sand-hopper Trinorchestia longiramus was analyzed in this study, which is the first for the genus within the family Talitridae. The mitogenome sequence is 15,401 bp in length containing two ribosomal RNA genes, 22 transfer RNA genes, 13 protein-coding genes, and a control region as found in most amphipods. The gene order showed that T. longiramus has a unique control region location compared to other amphipods. Phylogenetic analysis using the maximum likelihood method positioned T. longiramus within the monophyletic clades of the family Talitridae.

The complete mitochondrial genome of Alveopora japonica (Scleractinia: Acroporidae)

Here, for the first time, we sequenced the complete mitogenome of Alveopora japonica Eguchi, 1968 (Scleractinia: Acroporidae). Genome size was 17,886 bp with 13 protein-coding, two rRNA, and two tRNA genes. This gene composition was identical to the typical scleractinian pattern. Our results strongly support the recent transfer of this coral species to the family Acroporidae.

Complete sequence analysis of the mitochondrial genome of Auriculastra duplicata (Mollusca, Gastropoda, Ellobiidae)

The mitochondrial genome of the gastropod Auriculastra duplicata was completely sequenced. It was 13,920 bp in length and comprised 37 genes; two rrn genes and 22 trn genes. Phylogenetic analyses based on the concatenated protein-coding genes depicted the polyphyly of all species belonging to the family Ellobiidae; however, monophyly was observed among all species belonging to the subfamily Ellobiinae, in which A. duplicata clustered consistently with Auriculinella bidentata.

Full-length mitochondrial genome of the triton trumpet Charonia lampas (Littorinimorpha: Ranellidae)

The full-length mitochondrial genome of the triton trumpet Charonia lampas (Linnaeus, 1758) was analyzed by the primer walking method. Its mitogenome is 15,382 bp in length, comprising 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes. The gene order of C. lampas is congruent with those previously reported for the infraorder Littorinimorpha. This is the first full-length mitogenome sequence for the genus Charonia. In the phylogenetic tree, C. lampas formed a monophyletic group with the other species of the superfamily Tonnoidea, but did not show the closest phylogenetic relationship to a species from the same family, Ranellidae.

Dietary supplementation of probiotic Bacillus polyfermenticus, Bispan strain, modulates natural killer cell and T cell subset populations and immunoglobulin G levels in human subjects

A probiotic is a viable microbial dietary supplement that has beneficial effects such as prevention and treatment of specific gastrointestinal disorders, including counteracting gut barrier dysfunction associated with inflammation and infection. Probiotic Bacillus polyfermenticus, which is commonly called Bispan strain, has been appropriately used for the treatment of long-term intestinal disorders. The use of B. polyfermenticus for immune-related chronic intestinal disease may be appropriate considering that about 80% of the body's immune system is localized in the gastrointestinal tract. The current study aimed to evaluate the effect of probiotic B. polyfermenticus on the immune response of human subjects through the quantification of immune cell population and serum levels of immunoglobulins (Igs). Twenty-five male subjects, 20-35 years of age, were randomly assigned to either a control group (n =12) supplemented with a placebo or the experimental group (n = 13) supplemented with B. polyfermenticus tablets at a dose of 3.1 x 10(8) colony-forming units/day for 8 weeks. Dietary intake analyses from 3-day dietary records from three consecutive days including one weekend day and two weekdays revealed no significant differences in total energy and nutrient intakes between the two groups. The humoral immune response was monitored by the number of total B lymphocytes and serum concentrations of IgG, IgA, and IgM. To investigate the changes in immune cell populations, percentages of total T lymphocytes, CD4+ helper T cells, CD8+ cytotoxic T cells, and CD56+ natural killer (NK) cells were quantified. The concentration of IgG in the experimental group was 12% higher than in the placebo group after 8 weeks of Bispan supplementation. Also, the percentages of CD4+ helper T cells, CD8+cytotoxic T cells, and CD56+ NK cells in the Bispan strain-supplemented group were 32%, 28%, and 35% higher, respectively, compared with the control group. Because of a higher increment of the CD4+ T cell subset than CD8+ T cells, the ratio of CD4+/CD8+ T cells was greater in the experimental group. This study suggests that the supplementation of B. polyfermenticus has a potentially positive effect on immune function by enhancing IgG production as well as by modulating the number of immune cell population such as CD4+ and CD8+ T cells and NK cells.