In haiku there are various sorts of expressions
about trout—"autumn trout" and "descending
trout" and "rusty trout" are some I have heard.
"Descending trout" and "rusty trout" are trout
that have laid their eggs. Worn out, completely
exhausted, they are going down to the sea. Of
course there were occasionally trout that spent
the winter in deep pools. These were called
"remaining trout."