Kinship affects innate responses to a predator in bluegill Lepomis macrochirus larvae.

Naïve kin groups and mixed-family groups of bluegill Lepomis macrochirus larvae were exposed to a novel predator cue. The larvae responded by increasing shoal cohesiveness in kin groups but not in mixed-family groups; moreover, larvae sired by males of the 'cuckolder' life history tended to have an enhanced ability to respond to direct cues of kinship v. larvae sired by males of the 'parental' life history, which instead appeared to respond to cues of life history rather than relatedness per se. The increased shoal cohesion among related individuals probably confers a survival benefit and indicates that the antipredatory shoaling response is innate in L. macrochirus.