Furlan E O, Belotti E M, Alvez D M, Chemes S B, Beldomenico P M
Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral (UNL) / Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Esperanza, Santa Fe, Argentina; Laboratorio de Ecología, Conservación y Parasitología de Peces, Facultad de Humanidades y Ciencias, Universidad Nacional del Litoral (UNL), Santa Fe, Santa Fe, Argentina.
Laboratorio de Biología Celular y Molecular Aplicada, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral (UNL) / Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Esperanza, Santa Fe, Argentina; Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral (UNL), Esperanza, Santa Fe, Argentina.
Vet Parasitol. 2025 Aug;338:110551. doi: 10.1016/j.vetpar.2025.110551. Epub 2025 Jul 23.
Biosecurity in aquaculture is essential to reduce disease burden and ensure sustainability. Piaractus mesopotamicus (pacu) is a key species in South American aquaculture, yet parasitic threats to its health remain understudied. We analyzed intestinal helminth and assessed their effects on the health of 34 farmed pacu reared in intensive and semi-intensive systems in Santa Fe, Argentina, using parasitological, hematological, and histopathological approaches. Three parasite taxa were identified: the digenean Dadaytrema oxycephala (∼65 % prevalence; mean abundance: ∼3 parasites/fish), the nematode Rondonia rondoni (3 % prevalence; one host with 119 parasites), and the acanthocephalan Echinorhynchus jucundus (100 % prevalence; mean abundance: ∼235 parasites/fish). E. jucundus caused macrocytic hypochromic anemia (low erythrocyte count and hemoglobin, high MCV) and severe intestinal lesions (muscle penetration and chronic inflammation). D. oxycephala had marginal hematological effects. Infestations likely originated in land-based ponds, where zooplankton hosts thrive in the absence of technical biosecurity measures. Despite the high parasite burden, infected fish maintained stable body condition, suggesting a degree of physiological tolerance. However, the risk of nutrient malabsorption and market rejection remains. We propose: (1) prevention measures such as ≥ 15-day quarantine, pond sterilization, zooplankton monitoring in semi-intensive systems, water quality control in intensive systems, and necropsy of samples in cases of low feed conversion; (2) corrective action via targeted anthelmintic treatment or culling during outbreaks (>50 parasites/gut). This study identifies E. jucundus as an emerging pathogenic parasite and highlights the need for tailored biosecurity protocols adapted to different production systems, promoting the sustainable culture of pacu.
水产养殖中的生物安全对于减轻疾病负担和确保可持续性至关重要。美索不达米亚脂鲤（帕库鱼）是南美水产养殖中的关键物种，但其健康所面临的寄生虫威胁仍未得到充分研究。我们采用寄生虫学、血液学和组织病理学方法，分析了肠道蠕虫并评估了它们对阿根廷圣达菲集约化和半集约化系统中养殖的34条帕库鱼健康的影响。鉴定出三种寄生虫类群：复殖吸虫尖首达氏吸虫（感染率约65%；平均丰度：约3条寄生虫/鱼）、线虫罗氏朗多尼亚线虫（感染率3%；一条宿主鱼体内有119条寄生虫）和棘头虫秀丽棘头虫（感染率100%；平均丰度：约235条寄生虫/鱼）。秀丽棘头虫导致大细胞低色素性贫血（红细胞计数和血红蛋白降低，平均红细胞体积升高）和严重的肠道病变（肌肉穿透和慢性炎症）。尖首达氏吸虫对血液学有轻微影响。感染可能源自陆上池塘，在缺乏技术生物安全措施的情况下，浮游动物宿主大量繁殖。尽管寄生虫负荷很高，但受感染的鱼保持了稳定的身体状况，表明有一定程度的生理耐受性。然而，营养吸收不良和被市场拒收的风险仍然存在。我们建议：（1）采取预防措施，如为期≥15天的隔离、池塘消毒、半集约化系统中的浮游动物监测、集约化系统中的水质控制以及饲料转化率低时对样本进行尸检；（2）在疾病暴发期间（每克肠道>50条寄生虫）通过针对性驱虫治疗或扑杀采取纠正措施。本研究将秀丽棘头虫确定为一种新兴的致病寄生虫，并强调需要制定适合不同生产系统的定制生物安全方案，以促进帕库鱼的可持续养殖。
