许氏平鲉幼鱼对背景颜色的行为和生理响应

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

摘要:

目的 考查不同背景颜色对许氏平鲉幼鱼行为和生理的影响，探究其养殖的适宜背景颜色。方法 采用行为学和生理学方法，将实验鱼在红、蓝、黑、绿和白5种不同背景颜色下驯养4周后，测定了各组实验鱼的生长性能、个体行为和血清生理指标。结果 黑色背景组实验鱼的增重率和特定生长率均显著低于绿色和白色背景组。黑色背景组实验鱼的首次探索陌生物体时间显著高于绿色背景组，白色背景组的攻击次数显著高于蓝色和黑色背景组，白色背景组在明亮区域的停留时间百分比显著高于红色和黑色背景组。实验鱼的勇敢性与探索性和好斗性均呈正相关，而与焦虑水平则呈负相关，好斗性与活跃性呈正相关，而与焦虑水平则呈负相关。红色和绿色背景组实验鱼的红细胞比容(Hct)显著高于蓝色背景组，红色背景组的碱性磷酸酶(AKP)活性显著高于白色背景组，白色背景组的过氧化氢酶(CAT)活性显著低于红、蓝、黑色背景组，黑色背景组的超氧化物歧化酶(SOD)活性显著高于红色背景组。结论 背景颜色显著影响许氏平鲉幼鱼的生长性能、个性、血液携氧和抗氧化能力及非特异性免疫。不同个体行为指标之间存在相关性。红色背景组许氏平鲉幼鱼应激水平较高，而绿色背景有利于提高其福利水平。

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 analyses 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 significantly 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 behavior (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) activity 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, personality traits, oxygen-carrying capacity, antioxidant activity, and non-specific immunity of juvenile S. schlegelii, with correlations 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.