Scholarlink

<p>Global freshwater scarcity, progressive salinisation, and increasing anthropogenic pressures on aquatic ecosystems pose major constraints to the expansion of freshwater aquaculture. Utilisation of marginal and low-salinity brackish water resources represents a sustainable alternative, provided that species-specific salinity tolerance is well understood. In this study, the salinity tolerance and long-term physiological adaptability of red-bellied pacu (<i>Piaractus brachypomus</i>) were evaluated. A 96-h minimum lethal salinity (MLS<sub>96h</sub>) test showed no mortality at 10 ppt, while 100% mortality occurred at 15 ppt within 60&#xa0;h and at 20 ppt within 12&#xa0;h, identifying 15 ppt as the minimum lethal salinity. Based on these results, a 96-h acute toxicity bioassay was conducted across salinities of 11–15 ppt, including a control. Probit and logit analyses estimated the 96-h median lethal concentration (LC₅₀) at 12.54 ppt (95% confidence interval, 12.22–12.89 ppt). Subsequently, a 90-day growth and physiological performance trial was conducted using six treatments with triplicates: 0 (control), 2, 4, 6, 8, and 10 ppt. Growth performance and feed efficiency were significantly higher (<i>p</i> &lt; <i>0.001</i>) at 2 ppt, followed by the control, and declined progressively with increasing salinity. Survival remained 100% up to 8 ppt but decreased to 66.67% at 10 ppt. Haematological parameters (RBC, Hb, Hct) and serum protein levels peaked at 2 ppt, indicating effective osmoregulation, while higher salinities (&gt; 6 ppt) induced physiological stress, immune activation, enhanced antioxidant enzyme activity, elevated LDH levels, and progressive gill tissue damage. Whole-body proximate composition and muscle whiteness index were also highest at 2 ppt (<i>p</i> &lt; <i>0.001</i>). Overall, <i>P. brachypomus</i> tolerates brackish water conditions; however, a salinity of 2 ppt is likely recommended as its optimal salinity, maintaining growth performance and mitigating physiological stress. A practical operational salinity range of 2–6 ppt may be recommended for commercial culture, demonstrating the species potential for sustainable aquaculture in low-salinity and marginal brackish water systems.</p> Graphical abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Growth optimisation and physiological performance of red-bellied pacu, Piaractus brachypomus (Cuvier, 1818) in low-salinity culture systems

  • 期刊论文

  • 发表日期：

    2026年7月30日

查看全文
  • Pachiyamman Sakthivel Prathib,
  • Debajit Sarma,
  • Madhuri S. Pathak,
  • Paramita Banerjee Sawant,
  • Tincy Varghese,
  • Madhurya Sharma,
  • Surya Kanagaraju,
  • Jakir Hussain,
  • Atul Kumar Singh,
  • Vanlaltlan Kima,
  • G. Harini,
  • Gokul S.,
  • Kavitha Murugesan

摘要

Global freshwater scarcity, progressive salinisation, and increasing anthropogenic pressures on aquatic ecosystems pose major constraints to the expansion of freshwater aquaculture. Utilisation of marginal and low-salinity brackish water resources represents a sustainable alternative, provided that species-specific salinity tolerance is well understood. In this study, the salinity tolerance and long-term physiological adaptability of red-bellied pacu (Piaractus brachypomus) were evaluated. A 96-h minimum lethal salinity (MLS96h) test showed no mortality at 10 ppt, while 100% mortality occurred at 15 ppt within 60 h and at 20 ppt within 12 h, identifying 15 ppt as the minimum lethal salinity. Based on these results, a 96-h acute toxicity bioassay was conducted across salinities of 11–15 ppt, including a control. Probit and logit analyses estimated the 96-h median lethal concentration (LC₅₀) at 12.54 ppt (95% confidence interval, 12.22–12.89 ppt). Subsequently, a 90-day growth and physiological performance trial was conducted using six treatments with triplicates: 0 (control), 2, 4, 6, 8, and 10 ppt. Growth performance and feed efficiency were significantly higher (p < 0.001) at 2 ppt, followed by the control, and declined progressively with increasing salinity. Survival remained 100% up to 8 ppt but decreased to 66.67% at 10 ppt. Haematological parameters (RBC, Hb, Hct) and serum protein levels peaked at 2 ppt, indicating effective osmoregulation, while higher salinities (> 6 ppt) induced physiological stress, immune activation, enhanced antioxidant enzyme activity, elevated LDH levels, and progressive gill tissue damage. Whole-body proximate composition and muscle whiteness index were also highest at 2 ppt (p < 0.001). Overall, P. brachypomus tolerates brackish water conditions; however, a salinity of 2 ppt is likely recommended as its optimal salinity, maintaining growth performance and mitigating physiological stress. A practical operational salinity range of 2–6 ppt may be recommended for commercial culture, demonstrating the species potential for sustainable aquaculture in low-salinity and marginal brackish water systems.

Graphical abstract