琉球列島サンゴ礁域に生息するアワモチ科(軟体動物:腹側綱)の多様性、分布および食用利用に関する研究

Family Onchiiidae consists of air-breathing sea slug that lack internal or external shell. They are mostly found in intertidal areas across globe, except in the polar regions, and inhabit marine habitats. Although they are known to be commonly distributed in tropical to temperate of Indo-West Pacific region, information about the diversity of family Onchidiidae in the Ryukyu Islands is greatly lacking. Particularly, genus Peronia serves as an important traditional food source on many islands of the Ryukyus, but due to extremely similar gross morphology among the species, frequent misidentification of this family occurred in guidebooks and literatures. Accurate species identification requires detailed taxonomic analyses that incorporate molecular and morphological datasets, and literature reviews. Thus, in this thesis, I focused on three genera of family Onchidiidae; Peronia, Wallaconchis and Onchidella inhabit intertidal coral reef environments, and aimed to accomplish three goals. Firstly, I investigated the species diversity and distribution ranges of three genera across 40 intertidal areas in 11 islands of the Ryukyu Islands, with Chapter 1 focused specifically on genus Peronia and Chapter 2 adressed genera Wallaconchis and Onchidella. As a results of mitochondrial DNA barcoding using COI and 16S regions, the Ryukyu Islands harbor at least eight species from three genera; four species of Peronia (P. verruculata, P. peronii, P. okinawensis, and P. setoensis), three species of Wallaconchis (W. ater, W. nangkauriensis, and Wallaconchis sp.) and one species of Onchidella (Onchidella sp.). Species of Peronia distributed Iriomote-jima to Yakushima islands, and Wallaconchis and Onchidella are distributed in Okinawa-jima to Kikai-jima. Alive photographs of each species are also provided as potential identification tools, as well as to understand the colour variations observed within the species. Secondly, to enhance the molecular datasets of family Onchidiidae in public repositories, I aimed to provide the complete mitochondrial genomes of genus Peronia. The characteristics of mitogenomes of four species of Peronia are described in Chapter 4, with the first records of P. okinawensis and P. setoensis. It revealed that all species shared the same gene orientation and arrangement as previously described mitogenomes in family Onchidiidae. Thirdly, I aimed to explore the traditional Peronia fishery across eight islands through in-person interview with locals in Chapter 5. The Peronia fishery was observed from eight islands, either as active practice or one that has diminished over time. While locals recognized Peronia as a food source by locals, but familiarity with them varied slightly across eight islands. Overall, this thesis has revealed that currently the Ryukyu Islands hold the highest species diversity of genus Peronia, with four species coinhabit the same intertidal areas, as well as five species from three genera sympatrically existed. Although species of Onchidiidae can be currently considered as “common” in the Ryukyu Islands, more studies are needed to investigate the relationships between their diversity and the impacts of artificial disturbances, coastal developments, and overexploitations in intertidal areas to protect this unique biodiversity.博士（理学）http://purl.org/coar/resource_type/c_db06琉球大学University of the Ryukyu

沖縄島東海岸沖で発見したアオサンゴ大群集

We report here on a large Heliopora reef at depths of 2 to 10 m off the east coast of Okinawajima Island, Japan. The reef was approximately 4610 m2 in area, and was made of up “Heliopora sp. group sp. 2” sensu Taninaka et al. (2021). This reef is almost twice as large as a previously reported Heliopora reef in Oura Bay, also on the east coast of Okinawajima I., but of a different lineage. The discovery and presence of these large Heliopora reefs on the east coast of Okinawajima I. demonstrate both the diversity of the genus and how underwater surveys are still needed for this coastline. Future research on the east coast of Okinawajima I. may yet find further unreported Heliopora assemblages.http://purl.org/coar/resource_type/c_650

<i>Millepora</i> spp. as Substrates of Their Hydrozoan Counterparts <i>Stylaster</i> sp. in the Pacific Ocean

The association between two hydrozoans, Stylaster sp. and Millepora spp., has been described as a case of pseudo-auto-epizoism, and has only been reported from the Caribbean region of the Atlantic Ocean. Here, we report on the occurrence of this association in the Pacific Ocean on coral reefs around Iriomote-jima Island, Japan, suggesting the association to be more widespread than had previously been thought. Moreover, Stylaster sp. colonies were observed living healthily on bleached and dead branches of Millepora spp., indicating that this interaction is facultative. The interaction reported here differs from the relationship between the Caribbean Stylaster roseus and Millepora alcicornis by the connection points between the two partners, which is made evident by the whitening of the Millepora counterpart in Iriomote-jima Island, while being seamless in the Caribbean association. Further research is necessary to fully understand the nature of these relationships, comprehending under what conditions it occurs, and establishing which species are involved in the interactions

The Effect of Thickened Water on Ciprofloxacin Pharmacokinetics: A Comparative Study in Adult Males

Background/Objectives: The use of food thickeners with ciprofloxacin tablets may result in a gelatinous appearance and experience delayed dissolution, which presents a challenge for the drug&rsquo;s efficacy, creating a healthcare economic issue. However, the pharmacokinetic impact of this compound in humans remains uncertain. Therefore, a comparative pharmacokinetic study of ciprofloxacin was conducted on healthy adult Japanese males. Methods: We compared the effects of administering tablets with water or thickened water and crushed tablets mixed with thickened water. The maximum blood concentration (Cmax) of ciprofloxacin determines the drug&rsquo;s efficacy. Results: There were variations in drug absorption across different administration methods. The group who took the tablets immersed in thickened water exhibited different results in the area under the blood drug concentration&ndash;time curve (AUC) and Cmax compared to the group who took the tablets in regular water. Notably, the group that consumed the crushed tablets mixed with thickened water demonstrated equivalent results for both AUC and Cmax. Conclusions: Administering crushed tablets in thickened water may yield pharmacokinetics comparable to those of tablets taken with water. However, the process of crushing tablets may result in the loss of active ingredients and compromise the formulation, necessitating a comprehensive assessment before administration