Toxic Effects Of Chattonella Marina To Perna Viridis

As a harmful algae species, Chattonella marina is harmful and toxic to many ofaquatic organisms. In this paper, toxic effects of different cell densities of C. marinaand the mixture of C. marina and Tetraselmis subcordiformis on Perna viridis wasstudied. The results are hoping to provide a basis for preventing or reducing the lossesof shellfish caused by C. marina bloom. Four different cell densities of C. marinawere1×104cells.mL-1，1×103cells.mL-1，1×102cells.mL-1and1×10cells.mL-1. Threemixed groups were1×103cells.mL-1of C. marina mixed with5×102cells.mL-1of T.subcordiformis,5×102cells.mL-1of C. marina mixed with1×103cells.mL-1of T.subcordiformis and5×102cells.mL-1of C. marina mixed with5×102cells.mL-1of T.subcordiformis. Acute and chronic toxic effects of C. marina on P. viridis weredetected within24h and15days, respectively. The results were as follows.1. Acute effects of C. marina on P. viridis.High cell density of C. marina had inhibitory effects on the contents of GSH andMDA of P. viridis soft tissue, as well as on the activities of SOD, CAT and GPx,while low cell density of C. marina induced the contents of GSH and MDA of P.viridis soft tissue, as well as the activities of SOD, CAT and GPx. Medium celldensity of C. marina had no effect on P. viridis.2. Chronic effects of C. marina on P. viridisDuring the15days of chronic experiment, protein contents of P. viridis softtissue in all the experimental groups were significantly lower than the control group(P<0.01). The protein contents of P. viridis exposed to the highest cell density of C.marina were significantly lower than other three experimental groups on day15.During the15days of chronic experiment, fat content of control group also higherthan the experimental groups. Fat content of P. viridis exposed to the highest celldensity of C. marina was significantly lower than other3experimental groups.Induction–suppression effect on CAT and SOD activity of soft tissue was foundin all the high, medium and low cell densities of C. marina. In contrast, C. marina hadsuppression–induction effect on GPx activity. In addition, GSH content showed a law of induction–suppression in each cell density, and MDA content showed a law ofinduction-suppression-induction.3. Acute effects of the mixtures of C. marina and T. subcordiformis on P. viridisIn the group of C. marina of5×102cells.mL-1mixed with T. subcordiformis of1×103cells.mL-1, content of GSH and MDA and activities of SOD, CAT and GPx ofthe soft tissue of P. viridis were significantly impacted. Content of GSH and activitiesof SOD, CAT and GPx all showed a law of induction–suppression expect for MDAcontent.4. Chronic effects of the mixtures of C. marina and T. subcordiformis on P. viridisIn contrast with the control group, contents of protein and fat in soft tissue of P.viridis were significantly lower after P. viridis had been exposed to the mixtures of C.marina and T. subcordiformis with different cell densities on day5,10and15.Comparing the three mixed groups, average protein of P. viridis exposed to the mixedgroup of5×102cells.mL-1C. marina and T. subcordiformis1×103cells.mL-1werelowest on day5,10and15. Average fat of P. viridis exposed to the mixed group of5×102cells.mL-1C. marina and T. subcordiformis1×103cells.mL-1were lowest on day5,10and15.Contents of MDA in all the mixture groups increase firstly and then decreased.Content of GSH and activities of SOD, CAT and GPx induce significantly, and thendown to the control level in the group of C. marina of5×102cells.mL-1mixed with T.subcordiformis of1×103cells.mL-1.