养殖密度对玫瑰魮脂鲤生长、摄食及养殖水环境的影响

The Impact of Stocking Density on the Growth, Feeding, and Aquaculture Water Environment of Hyphessobrycon rosaceus

摘要:

养殖密度是影响鱼类福利的重要因素，本研究在7个养殖密度(D30：1.02 kg/m3、D45：1.53 kg/m3，D60：2.05 kg/m3，D75：2.56 kg/m3、D90：3.07 kg/m3，D105：3.58 kg/m3，D120：4.09 kg/m3)下，探究了养殖密度对玫瑰魮脂鲤生长、摄食以及养殖水体的影响。结果表明：存活率随养殖密度升高而降低，在第9天和第12天，D120组和D105组的存活率均低于60%；而在30天的养殖过程中，D90组存活率维持在97.8%以上，其他组均为100%。30天养殖后，D45组在增重率(WGR=59.91 ± 16.79%)和体重特定生长率(SGR=1.55 ± 0.35%/d)方面均表现最佳；而D90组的生长速度最慢(SGR=0.36 ± 0.09%/d)，显著低于其余各组(P<0.05)。饵料系数随养殖密度的提高呈先下降后上升趋势，D45饵料系数最小为1.96 ± 0.55，D90组的饵料系数最大为10.17 ± 2.64且显著高于各组(P＜0.05)。水质指标受密度胁迫随着时间增加，水体中氨氮含量随着时间及密度呈上升趋势，亚硝态氮和硝态氮呈上升后下降趋势；实验后期，除D90组外其余各组亚硝态氮含量趋于稳定，D90组亚硝酸盐(0.091 ± 0.023mg/L)最高且与D30、D45和D60组均有显著性差异(P＜0.05)；D90组硝态氮含量累计达到最高，为33.95 ± 4.61mg/L，显著高于各组(P＜0.05)；硝酸盐浓度最低的D45组(13.66 ± 4.14mg/L)与D30组(14.74 ± 0.55mg/L)无显著性差异。研究表明，养殖密度对玫瑰魮脂鲤的生长性能、摄食状态以及水质有显著影响，其最适的养殖密度为D45(1.53 kg/m3)，最适养殖密度下的体长(L)和体重(W)的回归方程为W45=1.61×10-5×L45 3.13(R2=0.78)。本研究首次对玫瑰魮脂鲤养殖密度进行了系统地研究，其研究结果可丰富观赏鱼养殖的相关数据，同时为玫瑰魮脂鲤的大规模人工培育提供理论依据。

Abstract:

The stocking density is an important factor influencing the welfare of fish. In this study, under 7 stocking densities (D30: 1.02 kg/m3, D45: 1.53 kg/m3, D60: 2.05 kg/m3, D75: 2.56 kg/m3, D90: 3.07 kg/m3, D105: 3.58 kg/m3, D120: 4.09 kg/m3), the effects of stocking density on the growth, feeding, and water quality of Hyphessobrycon rosaceus were investigated. The results showed that the survival rate decreased with the increase in stocking density. On the 9th and 12th days, the survival rates of the D120 and D105 groups were both below 60%, while during the 30-day culture period, the survival rate of the D90 group remained above 97.8%, with the other groups being 100%. After 30 days of culture, the D45 group exhibited the best performance in terms of weight gain rate (WGR=59.91 ± 16.79%) and specific growth rate (SGR=1.55 ± 0.35%/d); whereas the growth rate of the D90 group was the slowest (SGR=0.36 ± 0.09%/d), significantly lower than the other groups (P<0.05). The feed coefficient initially decreased and then increased with the increase in stocking density, with the D45 group having the smallest feed coefficient (1.96 ± 0.55) and the D90 group having the largest (10.17 ± 2.64), significantly higher than the other groups (P<0.05). Water quality parameters were affected by density stress over time, with ammonia nitrogen content increasing over time and density, while nitrite nitrogen and nitrate nitrogen initially increased and then decreased. In the later stages of the experiment, except for the D90 group, the nitrite nitrogen content of the other groups tended to stabilize. The nitrite nitrogen content in the D90 group (0.091 ± 0.023 mg/L) was the highest and significantly different from the D30, D45, and D60 groups (P<0.05). The nitrate nitrogen concentration in the D90 group accumulated to the highest level, reaching 33.95 ± 4.61 mg/L, significantly higher than the other groups (P<0.05); the D45 group had the lowest nitrate concentration (13.66 ± 4.14 mg/L), with no significant difference from the D30 group (14.74 ± 0.55 mg/L). The study showed that stocking density significantly influenced the growth performance, feeding status, and water quality of Hyphessobrycon rosaceus. The optimal stocking density was determined to be D45 (1.53 kg/m3), with the regression equation for body length (L) and body weight (W) at the optimal stocking density being W45=1.61×10-5×L453.13 (R2=0.78). This study provided a systematic investigation of stocking density for Hyphessobrycon rosaceus for the first time, enriching relevant data for ornamental fish culture and providing a theoretical basis for the large-scale artificial breeding of Hyphessobrycon rosaceus.