Interactions between Filter-Feeding Bivalves and Toxic Diatoms: Influence on the Feeding Behavior of Crassostrea gigas and Pecten maximus and on Toxin Production by Pseudo-nitzschia

Abstract

Among Pseudo-nitzschia species, some produce the neurotoxin domoic acid (DA), a source of serious health problems for marine organisms. Filter-feeding organisms—e.g., bivalves feeding on toxigenic Pseudo-nitzschia spp.—are the main vector of DA in humans. However, little is known about the interactions between bivalves and Pseudo-nitzschia. In this study, we examined the interactions between two juvenile bivalve species—oyster (Crassostrea gigas) and scallop (Pecten maximus)—and two toxic Pseudo-nitzschia species—P. australis and P. fraudulenta. We characterized the influence of (1) diet composition and the Pseudo-nitzschia DA content on the feeding rates of oysters and scallops, and (2) the presence of bivalves on Pseudo-nitzschia toxin production. Both bivalve species fed on P. australis and P. fraudulenta. However, they preferentially filtered the non-toxic Isochrysis galbana compared to Pseudo-nitzschia. The presence of the most toxic P. australis species resulted in a decreased clearance rate in C. gigas. The two bivalve species accumulated DA in their tissues (up to 0.35 × 10−3 and 5.1 × 10−3 µg g−1 for C. gigas and P. maximus, respectively). Most importantly, the presence of bivalves induced an increase in the cellular DA contents of both Pseudo-nitzschia species (up to 58-fold in P. fraudulenta in the presence of C. gigas). This is the first evidence of DA production by Pseudo-nitzschia species stimulated in the presence of filter-feeding bivalves. The results of this study highlight complex interactions that can influence toxin production by Pseudo-nitzschia and accumulation in bivalves. These results will help to better understand the biotic factors that drive DA production by Pseudo-nitzschia and bivalve contamination during Pseudo-nitzschia blooms.

Toxicological Evaluation of Acetylsalicylic Acid in Non-Target Organisms: Chronic Exposure on Mytilus galloprovincialis (Lamarck, 1819)

“…Since CECs can persist in the aquatic environment for long periods, the health concern about ASA and ASA-like contaminants is due to their implications for non-target aquatic organisms, that is, organisms that are not intended to be affected by these xenobiotics. Due to their feeding mode, filter-feeder organisms could be particularly exposed and sensitive to this class of pollutants ( Deeds et al, 2008 ; Albano, et al, 2021b ; Sauvey et al, 2021 ). For this reason, the Mediterranean mussel ( Mytilus galloprovincialis , Lamarck, 1819 ) has been chosen as a model organism in this study.…”

Effects of Harmful Algal Blooms on Fish and Shellfish Species: A Case Study of New Zealand in a Changing Environment

“…Effects on the feeding behaviour of bivalves have been observed in juvenile Pacific oysters, C. gigas , and scallops, P. maximus , exposed to French strains of P. australis and P. fraudulenta . Both bivalve species preferentially filtered non-toxic algae compared to the Pseudo-nitzschia cells and the clearance rate of C. gigas was reduced when exposed to toxic P. australis (see [ 47 ]). Interestingly, the presence of bivalves was found to induce an increase in the cellular DA contents of both Pseudo-nitzschia species [ 47 ].…”

“…Both bivalve species preferentially filtered non-toxic algae compared to the Pseudo-nitzschia cells and the clearance rate of C. gigas was reduced when exposed to toxic P. australis (see [ 47 ]). Interestingly, the presence of bivalves was found to induce an increase in the cellular DA contents of both Pseudo-nitzschia species [ 47 ]. Similarly, both juvenile and adult eastern oysters, C. virginica , and mussels, Mytilis edulis , were shown to reduce their clearance rate and increase pseudofaeces production when exposed to toxic P. multiseries [ 48 , 49 , 50 , 51 ].…”