The setting for egg cannibalism: aerial and underwater video sequences of brown trout (Salmo trutta) spawning. Sequences 1 and 2 illustrate various behaviours associated to spawning. The redd is dug by the female using tail movements, resulting in a nest pit strewn with coarse pebbles, followed by a dome of finer particles. To probe the nest pit, the female occasionally inserts her anal fin on the substrate. Nest digging lasts for ca. 4 hours (Esteve 2005) and spawning can occur at any hour of the day or night. The dominant male both courts the female (occasionally quivering alongside her; Jones and Ball 1954) during a few minutes to several hours by staying with her on the nest and chases peripheral males prowling around the nest. Both spawners emit their gametes simultaneously on the nest pit, after which the female covers the eggs with fine particles sent up by tail movements. Although brown trout is characterized by a highly variable life histories, it is considered iteroparous and promiscuous (Fleming 1998), each individual spawning several times per season (5.7 redds/female; Barlaup et al. 1994) for up to 4 seasons (Rubin et al. 2005), with several mates. Sequences 3 to 6 illustrate sequential promiscuity between two females and two males. Twenty underwater sequences were obtained with waterproof camera (Sony HQ1; angular field: 120°) placed on the streambed 1 meter from the nest, and connected to a personal computer for live sequence checking (using VirtualDub <b>...</b>