no reads :( (think he could be weak-tight)

Party Poker
No Limit Holdem Ring game
Blinds: $0.02/$0.04
9 players
Converter

Pre-flop: (9 players) Hero is BB with A:diamond: J:club:
UTG calls, UTG+1 folds, MP1 calls, 4 folds, SB calls, Hero checks.

Flop: 2:diamond: 6:heart: A:heart: ($0.16, 4 players)
SB checks, Hero bets $0.1, UTG raises to $0.2, 2 folds, Hero calls.

Turn: 6:club: ($0.56, 2 players)
Hero checks, UTG checks.

River: 8:spade: ($0.56, 2 players)
Hero bets $0.3, UTG raises to $0.8, Hero folds.
Uncalled bets: $0.5 returned to UTG.

Results:
Final pot: $1.16
I don't have a clue what he was on! :( :( Why did he check the river?