Document type: scientific article published in Aquaculture Reports
Authors: Tianyu Niu, Bochun Xiang, Puyi Huang, Xigui Yang, Longhui Chai
Preview: Auditory enrichment is an emerging method to enhance the welfare of ornamental fish, yet its effects remain poorly understood. This study evaluated how music style and tempo influence stress-related behaviors and cortisol secretion in two model species: zebrafish (Danio rerio) and guppies (Poecilia reticulata). Fish (n = 4 × 3 per species) were exposed for five consecutive days (4 h/day) to one of four auditory treatments-slow-tempo piano (SP, 40-65 bpm), fast-tempo piano (FP, 150-210 bpm), slow-tempo guzheng (SG), fast-tempo guzheng (FG)-or to silence (control). Positive behaviors (touching the water surface, following, wandering) and negative behaviors (freezing, aggression, sprinting) were quantified from 15-min video recordings. Whole-body cortisol concentrations were measured using ELISA. Music enrichment significantly affected both behavioral responses and cortisol levels (ANOVA, p ≤ 0.05). In zebrafish, SP and SG promoted positive behaviors, whereas FP and FG increased negative behaviors; SG alone significantly lowered cortisol relative to the control. In guppies, FP, SG, and FG increased positive behaviors; SG reduced negative behaviors; and all music treatments significantly decreased cortisol levels. Novel tank test performance was unaffected in either species. Overall, slow-tempo guzheng music exerted the strongest anxiolytic effect, particularly in guppies. We conclude that playback of slow guzheng music offers a practical, non-invasive approach to reduce stress and improve welfare in ornamental fish housed in barren aquaria.
