bet sizing river vs fish

Hi!

Fish 72/4 with 58 foldtocbet in 46 hands.

Would you raise river? How big? Do you think that he can have many TP when he potbets river?

Thanks!

Party, $0.25/$0.50 No Limit Hold'em Cash, 6 Players
Poker Tools Powered By Holdem Manager - The Ultimate Poker Software Suite.

SB: $53.11 (106.2 bb)
BB: $50 (100 bb)
UTG: $53.39 (106.8 bb)
Hero (MP): $60.92 (121.8 bb)
CO: $97.14 (194.3 bb)
BTN: $53.46 (106.9 bb)

Preflop: Hero is MP with K T
UTG calls $0.50, Hero raises to $2, 4 folds, UTG calls $1.50

Flop: ($4.75) Q 5 3 (2 players)
UTG checks, Hero bets $2.50, UTG calls $2.50

Turn: ($9.75) T (2 players)
UTG checks, Hero checks

River: ($9.75) T (2 players)
UTG bets $9.10, Hero ????