Aquatic insect (5,7)
I believe the answer is:
water boatman
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">aquatic insect</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for water boatman that I've seen before include "Carnivorous aquatic bug" , "Aquatic insect" , "Floating insect" , "Pond-skimming insect" .)