Rainfish

"'Insert some joke about Hailibut'"

Proverbs
Proverb Rainfish #1 Rainfish love to swin and play, when rain falls at height of day

Proverb Rainfish #2 In pounds where lilies sprout their flowers, Rainfish dwell for just 3 hours

Proverb Rainfish #3 To gain a more favourable eye, bake a Rainfish in a pie

Caught in/at
You can catch Rainfish when it's raining. It seems like this is true regardless of the time or location. You can also use the Rainstick to trigger rain, and then catch Rainfish that would otherwise be another type of fish.