The trophic mode of a phototrophic dinoflagellate is a critical factor in the dynamics of its harmful algal bloom. Recent discoveries of the mixotrophic capabilities of phototrophic dinoflagellates have changed the traditional view of bloom dynamics and prediction models. Here, mixotrophy in the harmful phototrophic dinoflagellate Takayama tasmanica was examined. Moreover, growth and ingestion rates of T. tasmanica on each of Alexandrium minutum CCMP1888 and Alexandrium tamarense CCMP1493, suitable prey, were determined as a function of prey concentration. This study reported for the first time that T. tasmanica is a mixotrophic species. Among the phytoplankton species offered as prey, T. tasmanica fed on all prey species whose equivalent spherical diameter (ESD) was greater than 30 μm, but also A. minutum whose ESD was 19 μm. In contrast, T. tasmanica did not feed on the phototrophic dinoflagellates Heterocapsa triquetra, Gymnodinium aureolum, Scrippsiella acuminata (previously S. trochoidea), Cochlodinium polykrikoides, Alexandrium affine, Alexandrium insuetum, and Alexandrium pacificum that its sister species Takayama helix is able to feed on. With increasing mean prey concentration, ingestion rates of T. tasmanica on A. minutum increased, but became saturated at the prey concentrations of >2130 cells mL⁻¹ (1070 ng C mL⁻¹). The maximum ingestion rate (MIR) of T. tasmanica on A. minutum was 0.5 ng C predator⁻¹ d⁻¹ (1.0 cells predator⁻¹ d⁻¹) which is only 64% of the body carbon of a T. tasmanica cell. Growth rates of T. tasmanica on A. minutum were not affected by prey concentrations. Thus, the low maximum ingestion rate is likely to be responsible for the small increases of its growth rate through mixotrophy. In addition, neither growth nor ingestion rates of T. tasmanica feeding on Alexandrium tamarense were affected by prey concentrations. The maximum ingestion rate of T. tasmanica on A. minutum was considerably lower than that of T. helix on the same prey species. Therefore, the mixotrophic ability of T. tasmanica is weaker than that of T. helix, and also T. tasmanica may have an ecological niche different from that of T. helix in marine ecosystems.

光养性鞭毛藻的营养模式是其有害藻华发生动力学的关键因素。对光养性鞭毛藻的混合营养能力的最新发现改变了传统的水华动力学和预测模型的观点。在这里，检查了有害的光养性鞭毛山楂塔斯马尼卡中的混合营养。此外，生长和摄食率T. tasmanica每个的亚历山大藻CCMP1888和亚历山大藻CCMP1493，合适的猎物，确定为猎物浓度的函数。这项研究首次报道塔斯马尼亚锥虫是混养物种。在被捕食的浮游植物中，T. tasmanica饲喂所有猎物物种，其等效球体直径（ESD）大于30微米，也A.藻其ESD为19μm。相比之下，T. tasmanica没食光养甲藻Heterocapsa竹叶，裸甲藻aureolum，锥状喜树（以前S.斯氏藻），Cochlodinium polykrikoides，亚历山大仿射，亚历山大insuetum和亚历山大pacificum其姊妹种高山螺旋能够进上。随着平均猎物浓度的增加，摄食速率为在细小曲霉上的塔斯马尼亚锥虫增加，但在> 2130个细胞mL ^-1（1070 ng C mL ^-1）的猎物浓度下变得饱和。的最大摄取速率（MIR）T. tasmanica上A.藻为0.5 ngÇ捕食^-1 d ^-1（1.0细胞捕食^-1 d ^-1），它是体内碳的仅64％T. tasmanica细胞。的增长率T. tasmanica对微小亚历山大藻不受猎物浓度的影响。因此，低的最大摄食率可能是由于混合营养导致其增长率的小幅增长的原因。此外，以塔玛亚历山大草为食的塔斯马尼亚锥虫的生长或摄食率均不受猎物浓度的影响。最大摄食率T. tasmanica对微小亚历山大藻比的是显着地降低T.螺旋在相同的猎物。因此，塔斯马尼亚锥虫的混合营养能力要弱于螺旋线虫，而塔斯马尼卡氏菌的生态位也可能不同于螺旋线虫。 在海洋生态系统中。