Fig. 2

Behavioral patterns of newly hatched (day 0) Acipenser gueldenstaedtii prelarvae under light (L; 450 lx on average; a), dim light (DL; 10 lx; b), and dark (D; < 1 lx; c) conditions. Behavioral patterns are categorized into negative geotaxis with passive drift (I), non-locomotory stay on the bottom (II), moving across the bottom of the tank (III), moving along the walls of the tank (IV), and gathering at the corners of the tank (V). Means ± SDs are based on three replicate tanks. Significant differences were found only under D conditions based on analysis of variance (ANOVA) followed by Duncan’s multiple range tests (P < 0.05; indicated by asterisks). Representative images showing sedentary behavior and the onset of early corner-gathering behavior of the hatched prelarvae are provided in Additional file 2: Figure S2