Characterization of Spawning Behavior in Cultured Delta Smelt

We examined cultured Delta Smelt Hypomesus transpacificus under laboratory settings to provide the first formal characterization of spawning behavior, which included quantification participants and diel patterns. video recorded behavioral observation trials in four mature males ripe females interacted freely for 9–11 d. found that three behaviors were consistently associated with egg release: (1) two or more fish swam close proximity one another just above substrate tank floor, (2) together synchronously during fast, forward-swimming movements (bouts) while tandem another, (3) female(s) released eggs male(s) presumably milt bouts. also five participated any given spawn occurred at night. Furthermore, spawns observed across consecutive nights within a trial up 17 times night, indicating individuals spawned serially single clutch cycle. This study enhances our understanding mating system informs ongoing conservation efforts.