How we cite our quotes: (Line)
Quote #1
battered and venerable (line 8)
The fact that the fish is beat up makes him worthy of the speaker's respect somehow. If you respect something/someone you're humbled by it, right?
Quote #2
I admired his sullen face, (line 45)
This line works the same way line 8 does. The speaker respects and admires this fish, and therefore is becoming humbled by him.
Quote #3
Like medals with their ribbons
frayed and wavering,
a five-haired beard of wisdom (lines 60-62)
OK, so he's gone from a fish to a straight-up wise old man. The respect for this fish has only grown over the course of the poem.
Quote #4
I stared and stared
and victory filled up (lines 64-65)
The speaker is so in awe of this fish, that she has given up the urge to "conquer" or "beat" him and sees this victory as belonging to the venerable fish. Also the victory could be the speaker's but in the sense that she was afforded the experience. In other words, the speaker feels lucky to have encountered such an amazing fish.