Zoological Science最新文献_第3页

History of Population Formation for the Red Fox Around the Japanese Archipelago, Revealed by Ddrad-Seq Analysis. Ddrad-Seq分析揭示日本列岛附近赤狐种群形成的历史。

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250063

Ryutaro Tomita, Yu Endo, Yosuke Amaike, Kohji Uraguchi, Yayoi Kaneko, Alexei V Abramov, Alexander P Saveljev, Pavel A Kosintsev, Alexey P Kryukov, Stanislava Peeva, Evgeniy Raichev, Atsushi J Nagano, Ryuichi Masuda

{"title":"History of Population Formation for the Red Fox Around the Japanese Archipelago, Revealed by Ddrad-Seq Analysis.","authors":"Ryutaro Tomita, Yu Endo, Yosuke Amaike, Kohji Uraguchi, Yayoi Kaneko, Alexei V Abramov, Alexander P Saveljev, Pavel A Kosintsev, Alexey P Kryukov, Stanislava Peeva, Evgeniy Raichev, Atsushi J Nagano, Ryuichi Masuda","doi":"10.2108/zs250063","DOIUrl":"https://doi.org/10.2108/zs250063","url":null,"abstract":"The red fox (Vulpes vulpes), which is widely distributed across the Northern Hemisphere, including Japan, has been studied for its distribution patterns and migration timing, but its population demography remains poorly understood. To solve it, this study conducted double-digest restriction-site-associated DNA sequencing (ddRAD-seq) on 118 samples from Japan, continental Eurasia, and Sakhalin. Based on single nucleotide polymorphisms (SNPs) detected by ddRAD-seq, this study revealed large genetic differentiation among populations of western Eurasia and four Japanese islands (Hokkaido, Honshu, Shikoku, and Kyushu). The eastern Eurasian population, including Sakhalin, was admixed with the western Eurasian and Hokkaido populations. Our results are consistent with previous reports based on mitochondrial DNA analyses that the Hokkaido and Honshu/Shikoku/Kyushu populations migrated from the continent independently. Demographic simulations showed that the Honshu/Shikoku/Kyushu population could have diverged first from the eastern continental Eurasian population, and that subsequently the Hokkaido population diverged. The simulation results are consistent with the geological record in that Honshu/Shikoku/Kyushu islands were the first to separate from continental Eurasia, followed by the isolation of Hokkaido. We propose a scenario in which the two fox populations in the Japanese archipelago became differentiated genetically as the result of geographical isolation from continental Eurasia by straits. In addition, a clustering analysis showed that foxes on Hokkaido could have become genetically divided into two subpopulations, northeastern and southwestern, suggesting that the Ishikari Lowland located between the two subpopulations served as a barrier to fox dispersal.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"271-279"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Y-Chromosomal and Mitochondrial DNA Analyses Suggest Male-Biased Dispersal in a Mountain Ungulate, Capra sibirica. y染色体和线粒体DNA分析表明一种山地有蹄类动物西伯利亚卡普拉的雄性偏向性扩散。

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250034

Yi-Xin Yu, Rui-Rui Wang, Shamshidin Abduriyim

{"title":"Y-Chromosomal and Mitochondrial DNA Analyses Suggest Male-Biased Dispersal in a Mountain Ungulate, Capra sibirica.","authors":"Yi-Xin Yu, Rui-Rui Wang, Shamshidin Abduriyim","doi":"10.2108/zs250034","DOIUrl":"https://doi.org/10.2108/zs250034","url":null,"abstract":"Dispersal is a fundamental biological phenomenon with critical implications for ecology, evolutionary biology, and conservation biology. The Asiatic ibex (Capra sibirica), a keystone ungulate species in the mountainous ecosystems of Central Asia, is of significant conservation concern both globally and regionally. Ecological traits of this species suggest a potential prevalence of male-biased dispersal. To investigate this hypothesis, we analyzed mitochondrial cytochrome b, D-loop, and Y-chromosomal SRY intron sequences from individuals sampled across diverse geographical populations in Xinjiang, China. Our analysis identified 32 distinct mtDNA haplotypes from 89 individuals and 11 SRY haplotypes from 36 male individuals. Phylogenetic analysis of maternal sequences revealed that mtDNA haplotypes clustered into four well-defined clades, while paternal sequences, as indicated by SRY haplotypes, predominantly grouped into two major clusters. Genetic differentiation analyses, employing FST for mtDNA and RST for Y-chromosomal polymorphisms, demonstrated significant and pronounced genetic divergence among geographical populations. Notably, the extent of differentiation varied between mtDNA and SRY markers. Extended Bayesian skyline plot and neutrality tests indicated similar historical population demography for both male and female populations, but Mantel tests showed sex-specific patterns of isolation-by-distance. The observed patterns of haplotype clustering, haplotype sharing, and population differentiation collectively suggest that the Asiatic ibex likely exhibits male-biased dispersal. However, these findings warrant further validation through integrative approaches in future studies.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"250-260"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Diversity of Exumbrellar Surface in Jellyfish with Remarks on the Optical Property of a Microvillar Array. 水母伞状表面的多样性及其微室阵列光学特性的评述。

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250090

Jun Nishikawa, Daisuke Sakai, Hiroshi Kakiuchida, Euichi Hirose

{"title":"Diversity of Exumbrellar Surface in Jellyfish with Remarks on the Optical Property of a Microvillar Array.","authors":"Jun Nishikawa, Daisuke Sakai, Hiroshi Kakiuchida, Euichi Hirose","doi":"10.2108/zs250090","DOIUrl":"https://doi.org/10.2108/zs250090","url":null,"abstract":"To understand the adaptation of body surface structures, the ultrastructure and optical properties of exumbrellar tissue were examined in cnidarian jellyfish, in which the epidermis is directly exposed to the external environment. The microscopic morphology of the exumbrellar epidermis varies from species to species. It can be flat or uneven, with/without cellular bulges, cilia, or an array of microvilli. Rigorous coupled wave analysis indicates that the light reflectance on the exumbrellar surface is expected to be very low owing to the very small differences in the refractive indices between exumbrella and seawater. The nanostructures modeled from the microvillar array of Spirocodon saltatrix reduced the reflection of light with large incident angles, which potentially affected the visibility of the contour of the umbrella. Therefore, the microvillar array may serve functions comparable to those of the nano-scale nipple array in some other metazoans. Moreover, an uneven pitch (distance between the apexes of neighboring microvilli) in the microvillar array potentially enhances the anti-reflection property. Although the difference in reflection reduction was only slight, this may be an example of unevenness in real biological structures that enhances the functional properties of the nanostructure.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"288-299"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evolution of Vanadium-Binding Protein (Vanabin) Gene Structure in Phlebobranchia and Aplousobranchia Ascidian Lineages. 白鲑和海鞘Aplousobranchia的钒结合蛋白（Vanabin）基因结构的进化

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250091

Tri Kustono Adi, Manabu Fujie, Noriyuki Satoh, Tatsuya Ueki

{"title":"Evolution of Vanadium-Binding Protein (Vanabin) Gene Structure in Phlebobranchia and Aplousobranchia Ascidian Lineages.","authors":"Tri Kustono Adi, Manabu Fujie, Noriyuki Satoh, Tatsuya Ueki","doi":"10.2108/zs250091","DOIUrl":"https://doi.org/10.2108/zs250091","url":null,"abstract":"Ascidians within order Phlebobranchia can accumulate extremely high levels of vanadium (V) in their blood cells. Several V-related proteins, including V-binding proteins (vanabins), have been isolated from V-accumulating ascidians. Vanabins were first isolated from a V-rich ascidian, Ascidia sydneiensis samea, belonging to Phlebobranchia. In this study, we searched for vanabin gene homologs in all available public databases containing tunicate genomic data and the draft genome database of A. sydneiensis samea constructed in this study. We found one to six vanabin genes per genome among all available genomes of Phlebobranchia species. We also found a vanabin gene in the genome of an Aplousobranchia species. Thus, we identified vanabins in seven ascidian species, and aligned these according to the C-Xn-C pattern common to the vanabin core domain. Based on a molecular phylogenetic tree derived from 18S ribosomal DNA and natural resistance-associated macrophage protein sequences, we propose a model for the evolution of vanabin gene structure via the following pathway: acquisition of ancestral vanabin by the common ancestor of Phlebobranchia and Aplousobranchia, followed by vanabin gene duplication; nonsynonymous mutation, insertion, and positive selection to create amino acid variation among vanabins; and extension of the vanabin gene cluster. The selective force acting within this pathway may have been V toxicity under high-V conditions.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"227-235"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Infestation of Rhinogobius flumineus (Family Gobiidae) by the Myxozoan Myxobolus nagaraensis in the Nagara River System, Central Japan. 日本中部永原河水系长垣粘虫对河豚鼻虾（虾科）的侵染。

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250110

Yasunori Koya, Shungo Matsuo, Kaede Ohno, Takashi Miyake

{"title":"Infestation of Rhinogobius flumineus (Family Gobiidae) by the Myxozoan Myxobolus nagaraensis in the Nagara River System, Central Japan.","authors":"Yasunori Koya, Shungo Matsuo, Kaede Ohno, Takashi Miyake","doi":"10.2108/zs250110","DOIUrl":"https://doi.org/10.2108/zs250110","url":null,"abstract":"Myxobolus nagaraensis is a species of myxozoa, a parasitic cnidarian that moves between fish and annelids, and was described in 2007 as a parasite of the genus Rhinogobius. The purpose of the present study was to clarify the actual status of parasitism of Rhinogobius flumineus by M. nagaraensis. Collection surveys conducted in the fall/winter season confirmed infestation at 18 of 38 locations of tributaries of the Nagara river. At all eight sites with high infection rates (> 9%) during fall/winter, the number of parasitized individuals decreased dramatically in spring/summer. The body length of the infected individuals was 20-45 mm, corresponding to yearlings or fish that had just turned 1 year old; no infestation was observed in older fish. In fall/winter, sites with high parasitism had significantly lower flow velocities and significantly higher electrical conductivity and total organic carbon compared to sites with no parasitism. In conclusion, infection with M. nagaraensis appears to occur locally through the migration of young R. flumineus into small, eutrophic tributaries with slow currents that are suitable for Oligochaeta habitat, and most of the infected fish subsequently die.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"280-287"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Morphology of a Novel Reproductive Strategy in the Pelvic-Brooding Ricefish Oryzias eversi Herder et al. 2012 (Adrianichthyidae, Teleostei). 盆腔育苗米鱼（Oryzias eversi Herder）新生殖策略的形态学研究等。2012（鲈科，鲈科）。

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250092

Takashi Iwamatsu, Toshiyuki Nishimaki, Shoji Oda, Hirokuni Kobayashi, Richard A Fluck, Alina Schüller, Julia Schwarzer, Lynne R Parenti, Atsunori Oga, Takafumi Katsumura, Motoyuki Ogawa, Kawilarang W A Masengi, Kazunori Yamahira

{"title":"Morphology of a Novel Reproductive Strategy in the Pelvic-Brooding Ricefish Oryzias eversi Herder et al. 2012 (Adrianichthyidae, Teleostei).","authors":"Takashi Iwamatsu, Toshiyuki Nishimaki, Shoji Oda, Hirokuni Kobayashi, Richard A Fluck, Alina Schüller, Julia Schwarzer, Lynne R Parenti, Atsunori Oga, Takafumi Katsumura, Motoyuki Ogawa, Kawilarang W A Masengi, Kazunori Yamahira","doi":"10.2108/zs250092","DOIUrl":"https://doi.org/10.2108/zs250092","url":null,"abstract":"We examined reproductive features of a pelvic brooder, the oviparous teleost Oryzias eversi. Eggs possess two types of filaments that form on the surface of the chorion during oogenesis: long attachment filaments at a restricted area around the vegetal pole, and sparse, short filaments around the animal pole (micropyle). Females spawned eggs through the genital pore when mating with the male. After spawning, females carried a cluster of fertilized eggs suspended from the genital pore by a bundle of long attachment filaments. Fertilized eggs were protected by the pair of long pelvic fins and held in an abdominal concavity posterior to those fins until hatching, about 12 days post-oviposition. During the period that females carried the fertilized egg cluster, the growth of oocytes slowed, and ovulation of a new batch of eggs did not occur. Thus, reproductive cycles in the female of O. eversi appear to depend upon the presence of hanging embryos.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"323-332"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improving the Resolution of Inter-Familial Relationships Within Palaeacanthocephala by Mitophylogenomics Including Isthmosacanthidae (Polymorphida) and Transvenidae (Echinorhynchida). 利用线粒体基因组学改进古棘头动物（Isthmosacanthidae）和Transvenidae （Echinorhynchida）家族间关系的解析。

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250099

Yuki Kita, Shimpei F Hiruta, Hiroshi Kajihara

{"title":"Improving the Resolution of Inter-Familial Relationships Within Palaeacanthocephala by Mitophylogenomics Including Isthmosacanthidae (Polymorphida) and Transvenidae (Echinorhynchida).","authors":"Yuki Kita, Shimpei F Hiruta, Hiroshi Kajihara","doi":"10.2108/zs250099","DOIUrl":"https://doi.org/10.2108/zs250099","url":null,"abstract":"The higher-level phylogeny of Palaeacanthocephala has remained unresolved, largely because traditional analyses using the mitochondrial (mt) cytochrome c oxidase subunit I, and nuclear (nc) 18S rRNA and 28S rRNA genes provide limited resolution for deeper nodes. Mt genomes have clarified some relationships, but several families-including Transvenidae and Isthmosacanthidae-have lacked any mitogenomic representation. In this study, we sequenced complete mt genomes from eight palaeacanthocephalan species, including the first representatives of these two families, and evaluated the phylogenetic performance of four datasets: (1) amino acid sequences of mt protein-coding genes, (2) their nucleotide sequences, (3) mt 12S and 16S rRNA gene sequences combined with the data in (2), and (4) nc 18S and 28S rRNA genes combined with the data in (3). Maximum-likelihood and Bayesian analyses revealed that the last dataset (4) produced the strongest and most stable support, recovering all major lineages of Echinorhynchida with high confidence and clarifying relationships among several historically problematic families. In contrast, internal relationships within Polymorphida remained weakly supported across all datasets despite the first mitogenomic inclusion of Isthmosacanthidae. All analyses consistently supported the paraphyly of Echinorhynchida with respect to Polymorphida. Although the present data do not yet permit robust inference of morphological character evolution, the well-supported phylogenetic backbone established here provides a critical foundation for re-evaluating classical morphological traits and for future integrative studies that incorporate nc genomic and transcriptomic data. Our findings substantially advance the systematic framework of Palaeacanthocephala and highlight key targets for future phylogenomic and comparative evolutionary research.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"300-311"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Versatile Technique for Measuring the Stiffness of Small Organisms Based on Microscopic Observation of Cantilever Strain. 基于悬臂应变微观观测的小生物刚度测量通用技术。

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250084

Shotaro Tanaka, Tokiko Saigo, Takekazu Kunieda, Yasuhiro Shiga, Fumio Nakamura

{"title":"A Versatile Technique for Measuring the Stiffness of Small Organisms Based on Microscopic Observation of Cantilever Strain.","authors":"Shotaro Tanaka, Tokiko Saigo, Takekazu Kunieda, Yasuhiro Shiga, Fumio Nakamura","doi":"10.2108/zs250084","DOIUrl":"https://doi.org/10.2108/zs250084","url":null,"abstract":"Small organisms such as water fleas and nematodes change their body stiffness in response to external stimuli and environmental alterations. Atomic force microscopy (AFM) is commonly used for stiffness measurement. However, the compression of the object by the cantilever is performed in the same direction as the observation, and this makes it difficult to observe the deformation of the object. Furthermore, the placement of the cantilever relative to the object is spatially quite limited and the driving distance is also very short: these limitations complicate measurements in organisms of various shapes and sizes. Here, we developed a new stiffness measurement technique using a cantilever attached to the tip of a micromanipulator, thereby overcoming these limitations of conventional AFM. During the compression of the object vertically downward, we observed the deformation from the side using a microscope tilted at 90°. The cantilever strain was monitored directly under the microscope rather than using the conventional optical reflection method. We used this approach to measure the stiffness of three small animal species, i.e., a tardigrade (Grevenius myrops), a nematode (Caenorhabditis elegans), and a water flea (Daphnia magna). We videotaped the compression of these organisms, and determined the strain distance of the object and cantilever from the images at different time points. A stress-strain curve was analyzed by plotting and Young's modulus was obtained as the curve's slope. Thus, Young's modulus data could be reliably obtained for varied organisms using the same device. This technology will facilitate measurements of stiffness of various small organisms.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"312-322"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geographical Variation and Migration History for Japanese Populations of the Masked Palm Civet (Paguma larvata), Revealed by Ddrad-Seq Analysis. Ddrad-Seq分析揭示了日本果子狸种群的地理变异和迁移历史。

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250094

Nana Komatsu, Yu Endo, Yoshinori Nishita, Kazuo Suzuki, Toshiaki Shiraishi, Keiji Ochiai, Hitomi Onuma, Koji Yamazaki, Tomoko Anezaki, Shuuji Yachimori, Liang-Kong Lin, Shih-Wei Chang, Yen-Jean Chen, Kurtis Jai-Chyi Pei, Yayoi Kaneko, Atsushi J Nagano, Ryuichi Masuda

{"title":"Geographical Variation and Migration History for Japanese Populations of the Masked Palm Civet (Paguma larvata), Revealed by Ddrad-Seq Analysis.","authors":"Nana Komatsu, Yu Endo, Yoshinori Nishita, Kazuo Suzuki, Toshiaki Shiraishi, Keiji Ochiai, Hitomi Onuma, Koji Yamazaki, Tomoko Anezaki, Shuuji Yachimori, Liang-Kong Lin, Shih-Wei Chang, Yen-Jean Chen, Kurtis Jai-Chyi Pei, Yayoi Kaneko, Atsushi J Nagano, Ryuichi Masuda","doi":"10.2108/zs250094","DOIUrl":"https://doi.org/10.2108/zs250094","url":null,"abstract":"With the globalization of human activities, invasions of non-native organisms into new habitats have increased. The masked palm civet (Paguma larvata) is an invasive alien species in Japan, with previous mitochondrial DNA studies indicating that Taiwan might be the source of the Japanese population. In addition, nuclear microsatellite data have shown a large genetic difference between the populations on Honshu and Shikoku islands. To further clarify the migration and expansion histories of this species, we analyzed the population genetics of P. larvata in Japan and Taiwan by using genome-wide SNP (single nucleotide polymorphism) data generated through ddRAD-seq. We found the previously unstudied population in western Honshu to be genetically closely related to that in central Honshu, with low genetic diversity due to a recent range expansion. The populations in Japan were genetically differentiated among Shikoku, western and central Honshu, and eastern Honshu. By admixture analysis, the Honshu and Shikoku populations showed affinity with one or two of them. Overall, the genetic diversity in Japan was lower than that in Taiwan, suggesting a founder effect during introduction from Taiwan. Within Japan, relatively higher variation in the eastern Honshu (especially Gunma Prefecture) populations indicated multiple introductions and/or different genetic lineages from those in Taiwan. Our study provides insights into the introduction history and migration routes of this alien species that can enhance management plans.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"261-270"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Light and Dark Types of Cladonema pacificum (Cnidaria, Hydrozoa): Reproductive Isolation between the Two Types Leading to Speciation. 太平洋枝线虫（刺胞纲，水螅纲）的明暗类型：两种类型之间的生殖隔离导致物种形成。

IF 1 4区生物学

Zoological Science Pub Date : 2026-06-01 DOI: 10.2108/zs250033

Noriyo Takeda, Takahito Hoshi, Fumiya Satoh, Keita Nishizumi, Nahomi Hongo-Yamakawa, Saki Ishimori, Haruka Satoh-Sugawara, Hiroshi Namikawa, Kazunori Tachibana, Ryusaku Deguchi

{"title":"Light and Dark Types of Cladonema pacificum (Cnidaria, Hydrozoa): Reproductive Isolation between the Two Types Leading to Speciation.","authors":"Noriyo Takeda, Takahito Hoshi, Fumiya Satoh, Keita Nishizumi, Nahomi Hongo-Yamakawa, Saki Ishimori, Haruka Satoh-Sugawara, Hiroshi Namikawa, Kazunori Tachibana, Ryusaku Deguchi","doi":"10.2108/zs250033","DOIUrl":"https://doi.org/10.2108/zs250033","url":null,"abstract":"Two types of Cladonema pacificum (Cnidaria, Hydrozoa) can be distinguished based on whether their medusae spawn after a dark-light transition (\"light type\") or a light-dark transition (\"dark type\"). To clarify how these two types are related, we characterized C. pacificum from different sites in the Tohoku region of Japan. Essentially, only dark-type medusae were captured in the Pacific Ocean side, whereas light- and dark-type medusae were found sympatrically at some sampling points in Mutsu Bay and in the Sea of Japan side. We observed that the spawning times of the sympatric light and dark types differed in the field, suggesting that the gametes of the two types rarely encounter each other. A comparison of the DNA sequences of mitochondrial COI and nuclear ITS1 of the analyzed individuals suggests that the two types belong to separate clades. In crossbreeding experiments, offspring of the light and dark types (F1 hybrids) developed into planula larvae and metamorphosed into polyps, which then produced medusae with normal morphology. The F1 hybrid medusae had characteristics that were intermediate between the two types in terms of their spawning in response to both dark-light and light-dark cues, but with less sensitivity than the parent medusae. When F1 hybrids were used as one or both parents, planula larvae failed to metamorphose into normal polyps. These results indicate that the light and dark types of C. pacificum exhibit both prezygotic and postzygotic isolation, accompanied by distinct DNA sequences; thus, they can be considered as undergoing speciation or as already distinct species.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 3","pages":"236-249"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148680154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0