Gut passage times in two bivalve molluscs fed toxic microalgae: Alexandrium minutum, A-catenella and Pseudo-nitzschia calliantha
|Author(s)||Gueguen Marielle1, Lassus Patrick1, Laabir Mohamed2, Bardouil Michele1, Baron Regis3, Sechet Veronique1, Truquet Philippe1, Amzil Zouher1, Barille Laurent4|
|Affiliation(s)||1 : IFREMER, Lab Phycotoxines, F-44311 Nantes, France.
2 : Univ Montpellier 2, CNRS, UMR UM2 5119, Lab Ecosyst Lagunaires, F-34095 Montpellier, France.
3 : IFREMER, Dept STAM, F-44311 Nantes, France.
4 : Lab Ecophysiol Marine Integree EA 2663, F-44322 Nantes 3, France.
|Source||Aquatic Living Resources (0990-7440) (EDP Sciences), 2008 , Vol. 21 , N. 1 , P. 21-29|
|WOS© Times Cited||8|
|Keyword(s)||Risk assessment, Toxic phytoplankton, Uptake, Gut passage, Mytilus edulis, Crassostrea gigas|
|Abstract||The occurrence of new phytoplankton species in a coastal area may be explained by the import of shellfish containing whole live algal cells in their digestive tracts. Indeed, shellfish containing toxic algal cells can induce both primary contaminations in safe areas ( initially free from toxic microalgae), and secondary contaminations of other shellfish growing in the same area via the faeces of the imported animals. To mitigate this problem, shellfish need to be placed in a separate holding tank and their intestinal content purged. For a deeper understanding of the risks associated with transferring contaminated shellfish, oysters ( Crassostrea gigas) and mussels ( Mytilus edulis) were purposely fed either Alexandrium minutum or A. catenella ( Dinophyceae) or Pseudo- nitzschia calliantha ( Bacillariophyceae) toxic algae for 2 h. They were then transferred into individual tanks where they were continuously fed with a non- toxic alga, Tetraselmis suecica. Biodeposit production, faeces composition, and filtration rates were monitored for the shellfish over a 6- h period. The effect of temperature differences and different initial toxic algae concentrations were compared. This study revealed a relationship between temperature and cell lysis in the oyster digestive tract. It also indicated that toxic algae concentration did not seem to influence gut passage time in oysters, while a significant effect was observed in mussels, and confirmed the existence of a difference between oyster and mussel feeding patterns.|