Mating system in a small pelagic spawner: field case study of the mandarinfish, Synchiropus splendidus

Abstract Mating systems in fishes are extremely diverse, ranging from monogamy to multiple polygamous forms, some of which include alternative male mating tactics within species. The major reproductive mode across approximately 33,000 bony is pelagic-spawning with external fertilization. Despite the dominance this mode, it relatively little studied field because greater mobility larger species typically makes individuals difficult follow for extensive periods, or catch and mark. However, smaller, more sedentary pelagic spawners provide excellent opportunities examine system variability response environmental conditions. mandarinfish, Synchiropus splendidus , a small spawner accessible divers. Its complex body markings distinctive variable allowing be identified followed repeatedly without need capturing marking fish. In over 400 h underwater surveys, we recorded movements, inter- intra-sexual behaviors, sex ratios, timing duration spawning activity focal fish predetermined study areas. We concluded that mandarinfish has pair-spawning. Females sequentially polyandrous, once nightly not at all, while males polygynous, up 8 times night. Males females use loosely defined sites on daily basis show flexibility their through differential movements according dispersion individuals, distances between temporally limited female receptivity. These results reveal an model studying field.