Fig. 1

Schematic summary of the behavioral modifications of Acipenser gueldenstaedtii during the prelarval period from day 0 to day 9 under an experimentally set diel light cycle (16 h of 450-lx daylight, 4 h of 10-lx dim light, and 4 h of < 1-lx darkness). Within a given behavioral criterion, ontogenetic intervals representing more pronounced and distinctive patterns are marked with darker colors. Two different onset patterns of rheotactic and non-rheotactic schooling are noted in pattern I and pattern II (for representative images, refer to Fig. 4). Pelagic swimming in the upper water column was not noted. Total length, body weight, and morphological development of the prelarvae during this period are referred to in Additional file 1: Figure S1