Castanho S, Califano G, Soares F, Costa R, Mata L, Pousão-Ferreira P, Ribeiro L
Portuguese Institute for the Ocean and Atmosphere (IPMA), Aquaculture Research Station (EPPO), Av. 5 de Outubro s/n, 8700-305, Olhão, Portugal.
Microbial Ecology and Evolution Research Group, Centre of Marine Sciences (CCMAR), Algarve University, Gambelas Campus, 8005-139, Faro, Portugal.
Fish Physiol Biochem. 2017 Aug;43(4):1043-1054. doi: 10.1007/s10695-017-0351-6. Epub 2017 Mar 17.
Larval rearing is affected by a wide range of microorganisms that thrive in larviculture systems. Some seaweed species have metabolites capable of reducing the bacterial load. However, no studies have yet tested whether including seaweed metabolites on larval rearing systems has any effects on the larvae development. This work assessed the development of Sparus aurata larvae fed preys treated with an Asparagopsis armata product. Live prey, Brachionus spp. and Artemia sp., were immersed in a solution containing 0.5% of a commercial extract of A. armata (Ysaline 100, YSA) for 30 min, before being fed to seabream larvae (n = 4 each). In the control, the live feed was immersed in clear water. Larval parameters such as growth, survival, digestive capacity (structural-histology and functional-enzymatic activity), stress level (cortisol content), non-specific immune response (lysozyme activity), anti-bacterial activity (disc-diffusion assay) and microbiota quantification (fish larvae gut and rearing water) were monitored. Fish larvae digestive capacity, stress level and non-specific immune response were not affected by the use of YSA. The number of Vibrionaceae was significantly reduced both in water and larval gut when using YSA. Growth was enhanced for YSA treatment, but higher mortality was also observed, especially until 10 days after hatching (DAH). The mortality peak observed at 8 DAH for both treatments, but higher for YSA, indicates larval higher susceptibility at this development stage, suggesting that lower concentrations of YSA should be used until 10 DAH. The application of YSA after 10 DAH onwards promotes a safer rearing environment.
幼体培育受到在幼体养殖系统中大量繁殖的多种微生物的影响。一些海藻物种具有能够降低细菌载量的代谢产物。然而，尚无研究测试在幼体培育系统中添加海藻代谢产物是否对幼体发育有任何影响。这项工作评估了用刺松藻产品处理过的猎物喂养的金头鲷幼体的发育情况。活饵，即臂尾轮虫属和卤虫属，在喂给鲷鱼幼体（每组(n = 4)）之前，先在含有(0.5%)刺松藻商业提取物（Ysaline 100，YSA）的溶液中浸泡(30)分钟。在对照组中，活饵浸泡在清水中。监测幼体参数，如生长、存活、消化能力（结构组织学和功能酶活性）、应激水平（皮质醇含量）、非特异性免疫反应（溶菌酶活性）、抗菌活性（纸片扩散法）以及微生物群定量（鱼幼体肠道和养殖用水）。使用YSA对鱼幼体的消化能力、应激水平和非特异性免疫反应没有影响。使用YSA时，水中和幼体肠道中的弧菌科数量均显著减少。YSA处理组的生长得到了增强，但也观察到了更高的死亡率，尤其是在孵化后(10)天之前。两种处理在孵化后第(8)天均观察到死亡率峰值，但YSA组更高，这表明幼体在此发育阶段更易感染疾病，建议在孵化后(10)天之前使用较低浓度的YSA。在孵化后(10)天及以后使用YSA可促进更安全的养殖环境。
