Coriander futures for April fell by Rs 31, or 0.45%, to Rs 6,750 per quintal in 29,660 lots.At the Multi Commodity Exchange (MCX), the May contract declined by Rs 28, or 0.40% to Rs 6,853 per quintal in 12,130 lots.Prices fell as as speculators booked profits at existing higher levels due to a decline in spot market demand.