Keratella cochlearis
... that the most widely distributed and commonest rotifer is probably Keratella cochlearis?
... that the most <a href="./Cosmopolitan_distribution" id="mwC7I" rel="mw:WikiLink" title="Cosmopolitan distribution">widely distributed</a> and commonest <a href="./Rotifer" id="mwC7M" rel="mw:WikiLink" title="Rotifer">rotifer</a> is probably <i id="mwC7Q"><b id="mwC7U"><a href="./Keratella_cochlearis" id="mwC7Y" rel="mw:WikiLink" title="Keratella cochlearis">Keratella cochlearis</a></b></i>?