Anti-grazing properties of the toxic dinoflagellate Karlodinium veneficum during predator–prey interactions with the copepod Acartia tonsa

Marine Ecology Progress Series

Patricia A. Tester¹  Allen R. Place¹  Rebecca J. Waggett¹ 

关键词: Copepod grazing;    Harmful algae;    Toxic dinoflagellate;    Chemical deterrent;    Karlodinium;    Karlotoxin;   

DOI  :  10.3354/meps07518

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Karlodinium veneficum (syn. Karlodinium micrum, Bergholtz et al. 2006; J Phycol 42:170–193) is a small athecate dinoflagellate commonly present in low levels in temperate, coastal waters. Occasionally, K. veneficum forms ichthyotoxic blooms due to the presence of cytotoxic, hemolytic compounds, putatively named karlotoxins. To evaluate the anti-grazing properties of these karlotoxins, we conducted food removal experiments using the cosmopolitan copepod grazer Acartia tonsa. Wild-caught, adult female A. tonsa were exposed to 6 monoalgal or mixed algal diets made using bloom concentrations of toxic (CCMP 2064) and non-toxic (CSIC1) strains of K. veneficum. Ingestion and clearance rates were calculated using the equations of Frost (1972). Exposure to the toxic strain of K. veneficum did not contribute to an increased mortality of the copepods and no significant differences in copepod mortality were found among the experimental diets. However, A. tonsa had significantly greater clearance and ingestion rates when exposed to a monoalgal diet of the non-toxic strain CSIC1 than when exposed to the monoalgal diet of toxic strain CCMP 2064 and mixed diets dominated by this toxic strain. These results support the hypothesis that karlotoxins in certain strains of K. veneficum deter grazing by potential predators and contribute to the formation and continuation of blooms.

【 授权许可】

Unknown