Thank director, who reportedly surveys aquatic larvae? (8)
I believe the answer is:
tadpoles
'larvae?' is the definition.
(I know this)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for tadpoles that I've seen before include "Baby frogs" , "Immature frogs" , "Little swimmers" , "Young frogs" , "Larvae of frogs or toads" .)