\n <\/p>\n
\u201cI study leeches called branchiobdellidans that live on crayfish. These leeches are just millimetres long and are symbionts \u2014 meaning they live in a close, long-term association with their host. They feed on microorganisms and debris that collect on the host\u2019s surface. In small numbers, they help to keep the crayfish clean, but in large colonies, they can become mildly parasitic.<\/p>\n
Here, I\u2019ve just caught a crayfish under torchlight, and I\u2019m holding it carefully so that the symbionts aren\u2019t washed away. After catching each crayfish, I measure its length and use a paintbrush to push a symbiont sample into a small vial. Tweezers would damage their delicate bodies.<\/p>\n
This photo was taken in June, in a small river in Slovenia where I recently discovered a new species of symbiont. Later, in the laboratory, I analysed the sample\u2019s DNA to trace how Astacus astacus \u2014 the noble crayfish \u2014 and its symbionts have evolved together over millions of years.<\/p>\n
The leeches aren\u2019t just passengers; they\u2019re bioindicators. When they disappear, it can be a signal that crayfish populations \u2014 and the rivers themselves \u2014 are in trouble. Invasive crayfish from North America (Pacifastacus leniusculus), which were introduced for farming, are already disturbing the ecological balance in waterways in Slovenia.<\/p>\n","protected":false},"excerpt":{"rendered":"
\u201cI study leeches called branchiobdellidans that live on crayfish. These leeches are just millimetres long and are symbionts \u2014 meaning they live in a close, long-term association with their host. They feed on microorganisms and debris that collect on the host\u2019s surface. In small numbers, they help to keep the crayfish clean, but in large<\/p>\n","protected":false},"author":1,"featured_media":35117,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[58],"tags":[15834,19850,19851,132],"class_list":{"0":"post-35116","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-chasing","9":"tag-crayfish","10":"tag-leeches","11":"tag-live"},"_links":{"self":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/35116","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=35116"}],"version-history":[{"count":0,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/35116\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/media\/35117"}],"wp:attachment":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=35116"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=35116"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=35116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}