Effect of Mozart's music (Romanze-Andante of “Eine Kleine Nacht Musik”, sol major, K525) stimulus on common carp (Cyprinus carpio L.) physiology under different light conditions

It is well known that music could have relaxing and antidepressant effects on humans, other mammals and birds. The present study aimed to evaluate music effects on common carp Cyprinus carpio growth and physiology, under different light conditions. Therefore, common carp (130.9 ± 0.67 g) was reared, in recirculating water system, under constant darkness (D) or normally illuminated conditions (L) for 12 weeks. Classical music was transmitted underwater and music treatments consisted of no music at all (control groups, C) and three music transmissions either of 30 min duration at 1.5 h intervals (M30) or of 60 min duration at 1 h intervals (M60). Obtained results showed that light conditions had a negative effect on fish growth (L–C versus D–C, P < 0.01), but when 30 min music was transmitted (L-M30) growth was improved and equal to D–C. Fish groups presenting reduced growth exhibited significantly increased brain neurotransmitters levels, indicating the occurrence of stressful conditions. Also, music transmission significantly affected carcass and liver fatty acid composition. Present results showed that music could be regarded as a stress relieving or inducing factor. Possible use of music as a growth and product quality promoter, as well as a means to ensure fish welfare under intensive fish farming is discussed.