Effect of Karenia mikimotoi on the survival of rotifer Brachionus plicatilis,brine shrimp Artemia salina,and Neomysis awatschensis

In this paper,we analyzed the distribution of blooms caused by Karenia sp.in China and the toxicity of Karenia mikimotoi to Brachionus plicatilis,Artemia salina,and Neomysis awatschensis.The population of B.plicatilis was significantly decreased when exposed to K.mikimotoi at low densities and the 24h EC50 was about 20 cells/mL.Comparison of the toxicities of different algal fractions showed that the algal culture and re-suspended algal cells had the adverse effects,but the broken cells and filtrate showed little impact,indicating that the inhibitory effect was mainly related to the active whole algal cells.The survival of A.salina or N.awatschensis was significantly decreased when exposed to K.mikimotoi.The results suggest that K.mikimotoi blooms might directly impact zooplankton survival.