Great scene. I’m assuming ‘fish’ has some colloquial poker slang meaning I don’t know, but I still got the point. The vaulting of the arms threw me, just cause I read the verb as a more sudden, violent action than I think you meant. Cool scene.
Also curious about the fish reference. I read it as a descriptive metaphor to represent the man’s physical appearance. I imagined him being “swollen” like the chinese goldfish for example.
I did end up looking it up and it means “A bad or weak poker player. A sucker.” I always love relevant slang used in fiction, my only suggestion is to add a small nudge for those readers unfamiliar with the slang. Something like “he was a fish—a sucker.” would give a noobie enough to roll with.