Back in early October, I posted...
I have an upper veggie pond dedicated to lillies, anachris, and duckweed
that I build this spring, filled around Memorial Day. The duckweed did
very poorly this year. We found out why recently... two fish squeaked
through the filters (I saw one when it was tadpole sized). We saw them
yesterday... they're about four or five inches long and plump... in five
months from fry. And these are definitely not oldtimers - we know all our
fish. Our other fish, the ones in the main pond, don't grow anywhere near
that quick... after a year, they may be two inches.

I caught one of the pups in the veggie pond (which is pseudo-greenhoused
and, despite being northeast of Seattle, still has some surviving water
hyacinths, new lily leaves, and duckweed.) Big pup. Five inches now, and
plump still. Gorgeous too... very light silver with transparent scales.
Perhaps due to the shaded life.

This one absolutely dwarfs its littermates, since we know it can't be more
than eight months old and saw it as a fry.

No sign of the other one, but that could just mean it's better at hiding.