The secret flies of Spanish fishermen competitors was revealed a few good years ago: Perdigon Nymphs. The Spanish guys had fantastic results with these flies. Now perdigon flies are not a secret anymore. At first look these flies are quite disappointing, very simple, overloaded with a big brass bead, slim body coated with resin. No dubbing, just a body thread and a strange black spot made of black marker in the wing case part. Everything has the logic here: slim body to let the fly sink fast, big bead to let the fly to go fast in the feeding area, black spot imitate the the thorax and works like a hot spot. These flies are tied on small and very small hooks and are used only in fast flowing rivers.