Behavioral responses of Crassostrea gigas exposed to the harmful algae Alexandrium minutum

Effects of toxic Alexandrium tamarense on behavior, hemocyte responses and development of brown ring disease in Manila clams

“…This suggests that behavioral responses are more sensitive, and may respond more rapidly, than hemocyte functional responses to the detrimental effects of PSTs. For example, highly reproducible behavioral effects of exposure to A. minutum were documented in Crassostrea gigas, as measured by valve activity, including a significant increase in the number of valve microclosures within 1 d of exposure to the toxic diet (Tran et al 2010). In their study, oysters were exposed to 4.7 ng STXeq ml -1 , a value comparable to that (3.4 ng STXeq ml -1 ) maintained in our juvenile experiment.…”

High Frequency Non-invasive (HFNI) Bio-Sensors As a Potential Tool for Marine Monitoring and Assessments

“…Under laboratory conditions, oysters were exposed to various simulated algal blooms of the toxic dinoflagellate Alexandrium minutum and the non-toxic dinoflagellate Heterocapsa triquetra or the Isochrysis galbana clone Tahiti. Gaping behavior of oysters differed between toxic and non-toxic treatments and were detected after ≈ 1 h. Organisms exposed to A. minutum increased both micro-closure activity and daily valve-opening duration while valve-opening amplitude decreased (Tran et al, 2010;Haberkorn et al, 2011;Mat et al, 2013). In a later study it was shown that daily gaping rhythmicity completely vanished in oysters exposed to the harmful algae (Tran et al, 2015).…”

“…To date tests have been carried out with blue and brown mussels Mytilus edulis and Perna perna, giant tropical clams Hippopus hippopus and Tridacna maxima, Icelandic scallops Chlamys islandica, black scallops (Chlamys varia), grooved carpet shell (Ruditapes decussatus), Pacific oysters Crassostrea gigas, black-lip pearl oysters (Pinctada margaritifera) and Asiatic clams Corbicula fluminea; • The system today is the only one to our knowledge which allows for simultaneous recordings of clam growth (Schwartzmann et al, 2011), valve activity behavior (Tran et al, 2010), biological rhythms and spawning (Bernard et al, 2016);…”

Effects of Alexandrium minutum exposure upon physiological and hematological variables of diploid and triploid oysters, Crassostrea gigas

“…Such changes of muscle tissue structure may be associated with the muscle paralysis observed during Alexandrium exposure in C. virginica and Mytilus edulis Galimany et al, 2008a). Observed myodegeneration may partially explain the modifications in valve activity of oysters exposed to A. minutum (Tran et al, 2010). Such modifications of muscle structure and activity can possibly affect oyster respiration and nutrition processes, as adductor muscle contraction contributes to maintenance of optimal amplitude of valve opening (Frank et al, 2007).…”

“…Presence of intact, harmful-algal cells in the digestive system of exposed bivalves has already been observed by Galimany et In a previous study, paralysis of adductor muscles of Crassostrea virginica was one visible effect observed upon Alexandrium fundyense exposure . Recently , Tran et al (2010) reported behavior changes in C. gigas upon exposure to A. minutum, e.g., increases in valve-opening duration and number of abnormal micro-closures. The latter is possibly related to dysfunction of adductor muscle.…”