12th International Conference on Harmful Algae

INTERNATIONAL SOCIETY FOR THE STUDY OF HARMFUL ALGAE12 th <strong>International</strong> <strong>Conference</strong> on Harmful Algae, Copenhagen, Denmark, 4-8 September 2006and one non-toxic reference strain,over a three-week period.Immunological analyses werecarried with mussels sampled at 0,7, 14 and 21 days.Results showed an increase in totalhaemocyte concentration after twoweeks and a subsequent decreaseafter this period. Furthermore,increased strain toxicity appeared tobe associated with a greaterdecrease in cell density. A higherproportion of granulocytes wasobserved in the very toxic strainsafter one week of exposure.Phagocytosis results revealed thatthe presence of MC-LF lowered theability of the mussels tophagocytose yeast particles andthis pattern was even more markedafter three weeks of exposure. Theconcentration of defence enzyme,lysozyme, was variable butincreased after two weeks ofexposure and decreasedsubsequently.In conclusion, microcystins(particularly MC-LF) elicited animmune response after one week ofexposure and gradually weakenedthe bivalve’s immune system,demonstrating another sublethaleffect of these toxins on bivalves.PO.10-29Ecological, morphological, andtoxicological analysis of anunusual dinoflagellate,Amphidinium massartiiSession: PO.10 - Ecophysiology &AutecologyTJ Cyronak, CR TomasUniversity of North Carolina Wilmington,WILMINGTON, United States of AmericaAmphidinium carterae, an importantharmful algal species that producespowerful antifungal and hemolyticcompounds, amphidinols, andcytotoxic macrolides,amphidinolides, is ubiquitous incoastal waters (Satake et al. 1991,Ishibashi and Kobayashi 1997).Samples observed from coral rubblecontained an Amphidinium sp. withthe unusual morphology ofcompletely circular cells.Preliminary genetic analysis bysequencing of LSU and SSU rDNAregions revealed a closerelationship between the unknownAmphidinium sp. and A. massartii.The unusual circular morphology ofA. massartii has not been reportedin previous literature. Anexamination of this morphologyunder temperature and nutrientregimes is conducted. Even thoughit is considered a toxic algaespecies, little information beyondthe description exists for A.massartii. Amphidinium massartii’sgenetic proximity to A. carterae iscause for interest in the productionof bioactive compounds. Twoassays used in the toxin detection ofA. carterae, a hemolytic assay andantifungal bioassay, offer goodmeasurements of relative toxicity(Echigoya et al. 2005). This unusualspecies of Amphidinium isexamined for its ecological,morphological, and toxicologicalproperties.PO.13-50Ten years of monitoring for toxicspecies of phytoplankton in theGulf of Gabes (South-EastTunisia)Session: PO.13 - Regional eventsHela Dammak-Zouari 1 , Asma Hamza 2 ,Malika Ben Hassen 2 , Wafa Feki 21 INSTM Tunisia, SFAX, Tunisia2 Institut National des Sciences et Techno,SFAX, Tunisia157