We evaluated the effect of light intensity on the specific growth rate (SGR), food intake (FI), food con-version efficiency (FCE), and the energy budget of red and green variants of the sea cucumber Apostichopus ja-ponicus. We reared 96 green (6.28 g ± 0.02 g) and 96 red (6.34 g ± 0.04 g) individuals under six light intensities (0, 50, 300, 1 000, 2 000, or 3 500 lx) for 60 d at 16°C. Light intensity had a significant effect on specific growth rate (SGR) (P<0.05) in both variants. Within the range of 50–3 500 lx, there was a negative relationship between the SGR of sea cucumber and illumination intensity. Both red and green variants grew fastest (P<0.05) at levels<50 lx. The maximum SGR, FI, and FCE (P<0.05) were observed in individuals reared under 50 lx. Stronger light inten-sity inhibits FI and reduces the efficiency of food conversion. The lower FCE under stronger intensity lighting may be function of the oxygen consumption rate (OCR). Our results suggest that OCR is significantly affected by light intensity (P<0.05). The minimum OCR was observed in animals reared under 50 lx, suggesting that little energy was expended on respiration, with most being invested in growth. Energy metabolism was significantly affected by light intensity (P<0.05). At light levels under 50 lx, A. japonicus allocate 7%for growth and 90%for respiration and production of feces. As light intensity increases, the energy allocated to growth decreases and is instead diverted to respiration and production of feces.% 实验所用仿刺参(Apostichopus japonicus)红色系和青色系体质量分别为(6.28±0.02) g和(6.34±0.04) g。实验设定5个光强处理组(50、300、1000、2000、3500 lx)和对照组(0 lx)。光照强度通过调节灯泡功率、数量以及灯源距离获得,光照周期为12L︰12D,养殖水温16~17℃。结果表明,两种色系仿刺参生长速度与光强呈负相关,弱光照时(50 lx)时生长速度最快。黑暗(0 lx)时两种色系仿刺参生长较弱光时(50 lx)略慢(P>0.05)。过强光照(3500 lx)抑制仿刺参的摄食率(P<0.05),降低其食物转化效率(P<0.05)。两种色系仿刺参的耗氧率随光照强度增强而逐渐增大。各处理组两种色系间仿刺参生长速率不存在显著差异(P>0.05)。仿刺参生长能(G/C)约7%,粪便能(F/C)和呼吸能所占比重超过90%。强光(3500 lx)下仿刺参排便能损失的比例增至59%,而生长能降至2%。从提高能量分配和饵料利用效率看,两种色系仿刺参生长速度较适宜光强为弱光(50 lx)。本研究旨在通过分析光照强度对生长、摄食、耗氧率和能量分配影响,并以青色系仿刺参作为对比,为红色系仿刺参在中国近海养殖提供基础参数。
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