This study assessed the impact of an acoustic stimulus on the behavioral responses and physiological states of the large yellow croaker (Larimichthys crocea). The test fish, with an average body weight of approximately 352.81 ± 70.99 g, were exposed to one hour of acoustic stimulation at seven different frequencies: 100 Hz, 125 Hz, 160 Hz, 200 Hz, 500 Hz, 630 Hz, and 800 Hz. The aim was to delineate the specific effects of acoustic stimulation on the behavior and physiological indices. The results show that acoustic stimulation significantly altered the behavioral patterns of the large yellow croaker, predominantly manifested as avoidance behavior towards the sound source. At a stimulus frequency of 630 Hz, the test fish exhibited continuous irregular motion and erratic swimming. Physiologically, one hour of exposure to acoustic stimulation notably affected the endocrine system. The levels of Epinephrine and thyroxine were significantly elevated at 200 Hz, while the cortisol levels did not show significant differences. Additionally, the lactic acid content significantly increased at 800 Hz, and the blood glucose content peaked at 630 Hz. This study discovered that sound frequencies of 200 Hz, 630 Hz, and 800 Hz led to a significant increase in the levels of Epinephrine, glucose, thyroid hormones, and lactate in large yellow croaker, consequently affecting their behavior. The changes in these physiological indicators reflect the stress response of the large yellow croaker in specific sonic environments, providing crucial insights into the physiological and behavioral responses of fish to acoustic stimuli.

In this study, passive acoustic technology was used to obtain sound signals indicative of feeding in individual rainbow trout (Oncorhynchus mykiss). Feeding signals were separated from background signals to characterize their acoustic parameters, in order to quantify feeding activity. The audio and video data of rainbow trout during feeding were synchronized to determine the signal category and mark it, and the time-domain features and frequency-domain features of fish swallowing feed were extracted. This not only has important theoretical value for in-depth understanding of fish growth, reproduction, and other life activities, but also provides data support and technical recommendations for future research on this topic.