Previous studies indicate differences in bloom magnitude and toxicity between regional populations, and more recently, between geographical isolates of Dinophysis acuminata; however, the factors driving differences in toxicity/toxigenicity between regions/strains have not yet been fully elucidated. Here, the roles of prey strains (i.e., geographical isolates) and their associated attributes (i.e., biovolume and nutritional content) were investigated in the context of growth and production of toxins as a possible explanation for regional variation in toxicity of D. acuminata. The mixotrophic dinoflagellate, D. acuminata, isolated from NE North America (MA, U.S.) was offered a matrix of prey lines in a full factorial design, 1 × 2 × 3; one dinoflagellate strain was fed one of two ciliates, Mesodinium rubrum, isolated from coastal regions of Japan or Spain, which were grown on one of three cryptophytes (Teleaulax/Geminigera clade) isolated from Japan, Spain, or the northeastern USA. Additionally, predator: prey ratios were manipulated to explore effects of the prey’s total biovolume on Dinophysis growth or toxin production. These studies revealed that the biovolume and nutritional status of the two ciliates, and less so the cryptophytes, impacted the growth, ingestion rate, and maximum biomass of D. acuminata. The predator’s consumption of the larger, more nutritious prey resulted in an elevated growth rate, greater biomass, and increased toxin quotas and total toxin per mL of culture. Grazing on the smaller, less nutritious prey, led to fewer cells in the culture but relatively more toxin exuded from the cells on per cell basis. Once the predator: prey ratios were altered so that an equal biovolume of each ciliate was delivered, the effect of ciliate size was lost, suggesting the predator can compensate for reduced nutrition in the smaller prey item by increasing grazing. While significant ciliate-induced effects were observed on growth and toxin metrics, no major shifts in toxin profile or intracellular toxin quotas were observed that could explain the large regional variations observed between geographical populations of this species.

先前的研究表明，区域种群之间，以及最近在地理上的Dinophysis acuminata分离株之间，绽放强度和毒性存在差异。然而，尚未完全阐明驱动区域/菌株之间毒性/产毒性差异的因素。在这里，在毒素的生长和产生的背景下研究了猎物菌株（即地理分离物）的作用及其相关属性（即生物量和营养成分），以此作为解释D. acuminata毒性的区域变化的可能解释。混合营养的鞭毛藻，D。acuminata ，从东北北美（马萨诸塞州，美国）分离出来，以全因子设计（1×2×3）提供了一个捕食系矩阵。一个甲藻菌株供电的两个纤毛虫，之一缢虫，从日本或西班牙的沿海区域，其生长在三个cryptophytes（一种分离Teleaulax / Geminigera从日本，西班牙，或美国东北部隔离进化枝）。此外，捕食：猎物比率操纵以探索猎物的总biovolume的效果鳍藻生长或毒素的产生。这些研究表明，两个纤毛虫的生物量和营养状况（对隐孢菌的影响较小）影响了D. acuminata的生长，摄食率和最大生物量。。捕食者对更大，更有营养的猎物的消费导致了增长率的提高，生物量的增加以及每毫升培养物中毒素配额和总毒素的增加。在较小，营养较少的猎物上放牧导致培养物中的细胞减少，但从每个细胞的角度来看，从细胞中渗出的毒素相对较多。一旦改变了捕食者：猎物的比例，使得每个纤毛的生物量相等，则纤毛大小的影响就消失了，这表明掠食者可以通过增加放牧来补偿较小猎物中营养的减少。虽然观察到纤毛虫对生长和毒素指标的显着影响，但未观察到毒素谱或细胞内毒素配额的重大变化，这可以解释该物种地理种群之间的较大区域差异。