{"id":2028,"date":"2025-07-17T06:02:13","date_gmt":"2025-07-17T06:02:13","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/2028\/"},"modified":"2025-07-17T06:02:13","modified_gmt":"2025-07-17T06:02:13","slug":"genetic-isolation-despite-geographic-proximity-highlights-the-threat-to-island-fish-species","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/2028\/","title":{"rendered":"Genetic isolation despite geographic proximity highlights the threat to island fish species"},"content":{"rendered":"<p>                <a href=\"https:\/\/www.eurekalert.org\/multimedia\/1082716\" rel=\"nofollow noopener\" target=\"_blank\"><\/p>\n<p>                    <img decoding=\"async\" src=\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2025\/07\/Public.jpeg\" alt=\"Underwater photograph of Luciogobius ryukyuensis\"\/><\/p>\n<p>                <\/a><\/p>\n<p>image:\u00a0<\/p>\n<p>Luciogobius ryukyuensis in a freshwater stream on Okinawa Island.<\/p>\n<p>                  <a href=\"https:\/\/www.eurekalert.org\/multimedia\/1082716\" rel=\"nofollow noopener\" target=\"_blank\">view more\u00a0<\/a><\/p>\n<p class=\"credit\">Credit: Ken Maeda<\/p>\n<p>Amphidromous fish \u2013 which migrate between freshwater streams and the sea \u2013 can move between habitats thanks to ocean currents. Since island streams are generally small and vulnerable to human impact, understanding how exactly fish populations are connected between streams and between islands is important for the conservation of geographically isolated species.\u00a0<\/p>\n<p>In a study now published in Scientific Reports, a team of researchers from the Okinawa Institute of Science and Technology (OIST) and collaborators sought to understand these dynamics by investigating the genetic connectivity among populations of the amphidromous goby Luciogobius ryukyuensis at four islands in the Ryukyu Archipelago in Japan: Okinawa, Kume, Ishigaki, and Iriomote.<\/p>\n<p>The researchers found that the populations are all genetically distinguishable, suggesting that larvae very rarely travel between the islands, despite relative physical proximity: Iriomote and Ishigaki share the same lagoon, and the populations are just 23km apart. Mitochondrial genome analysis suggested that the two clades \u2013 Okinawa and Kume, and Ishigaki and Iriomote \u2013 diverged approximately 900,000 years ago, and that there may have been a larval exchange between the two neighboring islands until more recently.<\/p>\n<p>Their findings highlight the challenges faced by amphidromous fish species in island ecosystems. In particular, the study shows the urgent need for increased conservation efforts targeting the highly vulnerable habitats of the goby, which are especially exposed on the smaller Kume, Ishigaki and Iriomote islands. For example, adult gobies have only been found in a 10m\u00b2 portion of the Urachi River on Kume Island. This habitat is surrounded by urban structures, and the upper watershed is developed for agriculture. Protecting and maintaining all existing habitats is critical for the conservation of the whole genetic diversity of this species.\u00a0<\/p>\n<p>                            Journal<\/p>\n<p>Scientific Reports<\/p>\n<p>                            Method of Research<\/p>\n<p>Data\/statistical analysis<\/p>\n<p>                            Subject of Research<\/p>\n<p>Animals<\/p>\n<p>                            Article Title<\/p>\n<p>Genetic isolation of an amphidromous goby species, Luciogobius ryukyuensis, highlights limited gene flow in small island populations<\/p>\n<p>                            Article Publication Date<\/p>\n<p>7-Jul-2025<\/p>\n<p>                            COI Statement<\/p>\n<p>The authors declare no competing interests.<\/p>\n<p>Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.<\/p>\n","protected":false},"excerpt":{"rendered":"image:\u00a0 Luciogobius ryukyuensis in a freshwater stream on Okinawa Island. view more\u00a0 Credit: Ken Maeda Amphidromous fish \u2013&hellip;\n","protected":false},"author":2,"featured_media":2029,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25],"tags":[49,48,316,66],"class_list":["post-2028","post","type-post","status-publish","format-standard","has-post-thumbnail","category-genetics","tag-ca","tag-canada","tag-genetics","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/2028","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=2028"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/2028\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/2029"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=2028"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=2028"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=2028"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}