Page 65 - 《水产学报》2025年第7期

魏涛，等 水产学报, 2025, 49(7): 079605

Behavioral and physiological responses of juvenile black rockfish
(Sebastes schlegelii) to background colors

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WEI Tao , HAN Yanke , WANG Xinyao , JIA Biao , TIAN Tao , YU Xiaoming 1,2*
1. Center for Marine Ranching Engineering Science Research of Liaoning Province,
Dalian Ocean University, Dalian 116023, China;
2. Key Laboratory of Environment Controlled Aquaculture, Ministry of Education,
Dalian Ocean University, Dalian 116023, China

Abstract: To investigate the effects of background colors on the behavior and physiology of juvenile Sebastes schlegelii and
identify suitable background colors for their growth, this study examined how five different background colors (red, blue, black,
green, and white) influenced growth performance, individual behavior, and serum physiological indicators. Correlation ana-
lyses among behavioral metrics were also conducted. The results showed that the black background group’s weight gain rate
(44.64%±21.09%) and specific growth rate (1.28%±0.53%) were significantly lower than those in the green (65.41%±25.64%,
1.76%±0.59%) and white (64.53±19.97, 1.75±0.44) groups (P<0.05). Fish in the black group (52.28%±11.11%) took signific-
antly longer to explore novel objects compared to the green group (22.82%±6.87%), while the white group (46.20±26.86)
exhibited significantly higher aggression frequencies than the blue (8.00±2.19) and black (8.10±3.44) groups. Additionally, the
white group (12.94%±6.07%) spent a significantly higher percentage of time in bright areas than the red (0.87%±0.36%) and
black (0.17%±0.10%) groups. Behavioral correlations revealed that boldness was positively associated with exploratory beha-
vior (P<0.05) and aggression (P<0.01) but negatively correlated with anxiety levels (P<0.05). Aggression was positively linked
to activity levels (P<0.05) but negatively related to anxiety (P<0.05). Physiological analyses indicated that the hematocrit (Hct)
levels in the red (37.87%±1.39%) and green groups (38.35%±1.28%) were significantly higher than those in the blue group
(30.15%±3.46%, P<0.05). The red group [(5.24±1.91) U/g prot] showed significantly higher alkaline phosphatase (AKP) activ-
ity than the white group [(1.74±0.16) U/g prot, P<0.05], while the white group [(144.87±19.38) U/mL] had significantly lower
catalase (CAT) activity than the red [(289.41±13.19) U/mL], blue [(258.47±22.17) U/mL], and black groups [(218.72±25.79)
U/mL, P<0.05]. The black group [(14.64±0.92) U/mL] exhibited significantly higher superoxide dismutase (SOD) activity than
the red group [(10.45±1.47) U/mL, P<0.05]. In conclusion, background color significantly affects the growth performance, per-
sonality traits, oxygen-carrying capacity, antioxidant activity, and non-specific immunity of juvenile S. schlegelii, with correla-
tions observed among individual behavioral indicators. The red background induced higher stress levels, whereas the green
background improved welfare. This study identifies optimal background colors for juvenile S. schlegelii, enriching theoretical
knowledge on how environmental enrichment influences fish behavior and physiology. The findings provide valuable insights
for enhancing aquaculture welfare and optimizing breeding techniques.
Key words: Sebastes schlegelii; environmental enrichment; background colors; behavior; physiology
Corresponding author: YU Xiaoming. E-mail: yxm@dlou.edu.cn

Funding projects: General Support Program of Liaoning Provincial Science and Technology Program Joint Fund; National
Key Research and Development Program of China (2023YFD2401103); Dalian Science and Technology Innovation Fund
Project (2021JJ11CG001)

https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
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