lizard goby
... that the lizard goby holds on to rocks in fast-flowing water by means of a "sucker" formed from two fins?
... that the <b id="mwA2U"><a href="./Rhinogobius_flumineus" id="mwA2Y" rel="mw:WikiLink" title="Rhinogobius flumineus">lizard goby</a></b> holds on to rocks in fast-flowing water by means of a "sucker" formed from two fins?