The suitability of fermented products of Ulva fronds as diets for juvenile asari clams was tested. Ulva fronds were transformed by fermentation into a single-cell product (Ulva marine silage; UMS) of suitable size for ingestion by the clams. No dietary effect was seen in clams fed UMS alone. Furthermore, combined feeding with UMS and Chaetoceros calcitrans, which is considered a suitable diet for clams, resulted in a reduction in growth. An aqueous suspension of Ulva fronds prepared without fermentation showed inhibitory effects on clam growth, which indicated that the presumed inhibitory component(s) originated from the Ulva fronds. Further feeding tests indicated that the component(s) that inhibited clam growth were water soluble and had a molecular weight of < 1000 Da. An authentic product of glucuronic acid, one of the major components of the water-soluble fraction of UMS, induced inhibitory effects on shell growth. However, further study is necessary to identify the components of Ulva fronds that inhibit growth in the asari clam. The results indicate that the utilization of Ulva fronds as marine silage for the asari clam is problematic because they appear to contain component(s) that inhibit clam growth.

中文翻译：

---

用石莼属（Ulva spp.）喂食的菲律宾蛤仔幼虾的生长抑制。海洋青贮

测试了石莼叶的发酵产品作为细小蛤仔幼年饲料的适用性。石莼叶通过发酵转化为适合蛤蜊摄入的单细胞产品（石莼海洋青贮饲料；UMS）。在单独喂食 UMS 的蛤中没有观察到饮食影响。此外，将 UMS 和 Chaetoceros calcitrans（被认为是蛤蜊的合适饮食）联合喂养导致生长减少。未经发酵制备的石莼叶水悬浮液对蛤的生长有抑制作用，这表明推测的抑制成分来自石莼叶。进一步的饲养测试表明，抑制蛤蜊生长的成分是水溶性的，分子量小于 1000 Da。正宗的葡萄糖醛酸产品，UMS 水溶性部分的主要成分之一，对壳生长产生抑制作用。然而，需要进一步研究以确定石莼叶中抑制细辛蛤生长的成分。结果表明，将石莼叶用作细纹蛤的海洋青贮饲料是有问题的，因为它们似乎含有抑制蛤生长的成分。