title: Effects of bioactive extracellular compounds and paralytic shellfish toxins produced by Alexandrium minutum on growth and behaviour of juvenile great scallops Pecten maximus.
abstract: Dinoflagellates of the genus Alexandrium are a major cause of harmful algal blooms (HABs) that have increasingly disrupted coastal ecosystems for the last several decades. Microalgae from the genus Alexandrium are known to produce paralytic shellfish toxins (PST) but also bioactive extracellular compounds (BEC) that can display cytotoxic, allelopathic, ichtyotoxic or haemolytic effects upon marine organisms. The objective of this experimental study was to assess the effects of PST and BEC produced by A. minutum upon juvenile great scallops Pecten maximus. Scallops were exposed for one week to two different strains of A. minutum, the first producing both PST and BEC and the second producing only BEC. Escape response to starfish, daily shell growth, histological effects, and accumulation of PST were recorded after one week of exposure, and after two subsequent weeks of recovery. Daily shell growth was delayed three days in scallops exposed to the BEC-producing A. minutum strain, probably during the three first days of exposure. An increase of reaction time to predators was observed in scallops exposed to the BEC condition, suggesting that BEC may have altered sensing processes. Scallops exposed to PST displayed a less-efficient escape response and muscular damage which could reflect the effects of paralytic toxins upon the nervous system of scallops. This study demonstrates contrasting effects of the distinct toxic compounds produced by A. minutum upon marine bivalves, thus highlighting the importance to better characterize these extracellular, bioactive compounds to better understand responses of other marine organisms.
authors.affiliation: Ifremer, LEMAR, UMR 6539 (UBO-CNRS-IRD-Ifremer), Centre de Bretagne, CS 10070, 29280 Plouzané, France. Electronic address: elodie.borcier@gmail.com.
authors.forename: Elodie
authors.initials: E
authors.lastname: Borcier
authors.affiliation: LEMAR, UMR 6539 (UBO-CNRS-IRD-Ifremer), Institut Universitaire Européen de la Mer, Technopôle Brest Iroise, Plouzané, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Morvezen
authors.affiliation: Ifremer, LEMAR, UMR 6539 (UBO-CNRS-IRD-Ifremer), Centre de Bretagne, CS 10070, 29280 Plouzané, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Boudry
authors.affiliation: Ifremer, LEMAR, UMR 6539 (UBO-CNRS-IRD-Ifremer), Centre de Bretagne, CS 10070, 29280 Plouzané, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Miner
authors.affiliation: LEMAR, UMR 6539 (UBO-CNRS-IRD-Ifremer), Institut Universitaire Européen de la Mer, Technopôle Brest Iroise, Plouzané, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Charrier
authors.affiliation: LEMAR, UMR 6539 (UBO-CNRS-IRD-Ifremer), Institut Universitaire Européen de la Mer, Technopôle Brest Iroise, Plouzané, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Laroche
authors.affiliation: LEMAR, UMR 6539 (UBO-CNRS-IRD-Ifremer), Institut Universitaire Européen de la Mer, Technopôle Brest Iroise, Plouzané, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Hegaret
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004141:Dinoflagellida / Q000737:chemistry; D008387:Marine Toxins / Q000633:toxicity*; D049897:Pectinidae / Q000187:drug effects* / Q000254:growth & development; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D008387:Marine Toxins; D014874:Water Pollutants, Chemical
keywords: Alexandrium minutum; Behaviour; Extracellular compounds; Harmful Algal Bloom (HAB); Histology; Paralytic Shellfish Toxins (PST); Pecten maximus