The Baetis fuscatus or Pale Watery Dun is a tiny and fragile mayfly which hatches from May through October. The hatches happen in discrete quantities with some peaks, through the all day, from morning to evening. The Pale Watery Dun’s importance for the fly angler may vary thoughout the year, depending from the presence of other species. It can become essential when the fish becomes extremely selective.The nymphs In spite of its tiny dimension the cromatic and morphlogic difference between sexes are observable with naked eye. The female is olive-yellow hue where the male is bright, almost transparent white. The male carry yellow turban eyes which may turn orange in the late imago. Male and female are also of different size, the female (right pictures) is normally bigger, in average about 7 mm. The male is smaller and measures 5 mm. The subimago turns to imago 12-24 hours after the hatch. The imago live another 1 or 2 days.