Sommen charrs
... that Sommen charrs are a relict population that has survived because of Lake Sommen's great depth, and its cold and oxygen-rich waters?
... that <b id="mwAjY"><a href="./Sommen_charr" id="mwAjc" rel="mw:WikiLink" title="Sommen charr">Sommen charrs</a></b> are a <a href="./Glacial_relict" id="mwAjg" rel="mw:WikiLink" title="Glacial relict">relict</a> population that has survived because of <a href="./Sommen" id="mwAjk" rel="mw:WikiLink" title="Sommen">Lake Sommen's</a> great depth, and its cold and oxygen-rich waters?