 In some species, release occurs when a fish attempts to attack the mussel's minnow or other mantle flaps shaped like prey; an example of aggressive mimicry.Glochidia are generally species-specific, and will only live if they find the correct fish host.Once the larval mussels attach to the fish, the fish body reacts to cover them with cells forming a cyst, where the glochidia remain for two to five weeks (depending on temperature).