Positive influence of diatom pigment marennine on oyster larvae survival

Ewa Górecka1, Réjean Tremblay2, Jean Bruno Nadalini2, Jordan Latour2, Romain Gastineau1 and Andrzej Witkowski1

 

1   Palaeoceanology Unit, Faculty of Geosciences, Natural Sciences Education and Research Centre, University of Szczecin, Mickiewicza 16a, 70-383 Szczecin, Poland and

2   Institut des sciences de la mer de Rimouski (ISMER), Université du Québec à Rimouski (UQAR), 310 des Ursulines, Rimouski, QC, G5L 3A1 Canada

 

The pigment marennine, produced by the naviculoid diatom Haslea ostrearia (Gaillon) Simonsen (Bacillariophyceae), is the cause of the ‘oyster greening’, a phenomenon famous in western France. Greening occurs after blooming of H. ostrearia, when significant amounts of marennine are being released from diatoms to the water body. The pigment is fixed in the gills of bivalves changing its colour to dark-green/grey. Besides the higher commercial value of green oysters (about 20% above the average price), the pigment is also known for its other properties, including antioxidant, antiviral, anticoagulant and growth inhibiting properties for various pathogenic bacteria or other diatom species. Hence, the investigations concerning the application of marennine-replete water in bivalves hatcheries is desirable. The aim of our study was to determine the influence of marennine enriched water on veliger larvae of Crassostrea virginica, more precisely their survival, growth, ingestion of bacteria and levels of accumulation of energetic lipids (TAGs) and essential fatty acids while infected with pathogenic bacteria Vibrio splendidus. The exposition to the pathogenic bacteria lasted 96 hours in combinations of: control batch (1), bacteria treatment (2), marennine treatment (3) and mix of bacteria and marennine (4), all done in triplicates. The result proved that marennine enriched water has a positive effect on larvae survival at the same time having no effect on the growth rate nor bacteria ingestion by larvae.