Both riders escaped suspension for brawling in full view of the public and television cameras immediately after the opening race Friday but were fined for "conduct against the best interest of horse racing."
Borel, who had to be restrained by security guards after instigating the fight in the winner's circle, was fined the maximum amount of $5,000 while Castellano was docked $2,500.
Castellano also was suspended for six racing days for causing interference during the race.
Borel, who rode the Kentucky Derby winner in three of the past four years, was enraged after he was almost knocked out of the saddle when Castellano, riding Prince Will I Am, veered out on the final turn and forced Romp to stumble in front of Borel's mount A.U. Miner.
Prince Will I Am crossed the line second behind winner Eldaafer but was disqualified by stewards.