Effects of domoic acid on haemolymph pH, PCO2 and PO2 in the Pacific oyster, Crassostrea gigas and the California mussel, Mytilus californianus

Domoic acid uptake and elimination kinetics in oysters and mussels in relation to body size and anatomical distribution of toxin

“…3b). Faster toxin loss in viscera relative to other tissues has been previously reported for DA-contaminated C. gigas [Jones et al (1995), but see Guéguen et al (2008)] and PST-contaminated M. arenaria (Bricelj and Cembella, 1995), likely due to a combination of egestion (i.e. direct loss in feces) and rapid toxin transfer to other tissues.…”

“…direct loss in feces) and rapid toxin transfer to other tissues. In C. gigas, exchange of DA between tissues was supported by continuously increasing toxin concentrations in non-visceral tissues during a period of persistent shell closure (Jones et al, 1995), which was likely caused by exposure to excessively high cell densities and prevented further DA intake.…”

“…The anatomical distribution of DA is also affected by the bivalve's capacity to transport DA across the gastrointestinal membrane after ingestion and to transfer substantial proportions of the total toxin from visceral to other tissues via the circulatory system. This capacity was suggested for C. gigas (Jones et al, 1995), but is lacking or limited in Pecten maximus (Blanco et al, 2002a). Therefore, visceral tissues (including the digestive gland) may account for 94-99% of the toxin burden in DA-contaminated P. maximus (Blanco et al, 2002a(Blanco et al, , 2006Campbell et al, 2003;Bogan et al, 2007), 93% in M. edulis (Grimmelt et al, 1990), but only 70% in C. virginica (Roelke et al, 1993) during the toxin uptake phase.…”

“…There is limited information on DA elimination kinetics by oysters, and it is derived from short-term (3-5 d) laboratory experiments (Roelke et al, 1993;Jones et al, 1995). Domoic acid elimination has been more extensively studied in mussels (Novaczek et al, 1992;MacKenzie et al, 1993;Whyte et al, 1995;Blanco et al, 2002b), but inter-species comparisons are made difficult by the inconsistent toxin exposure conditions used in different studies.…”

Mechanisms contributing to low domoic acid uptake by oysters feeding on Pseudo-nitzschia cells. I. Filtration and pseudofeces production

“…Bivalve molluscs, which can accumulate high DA levels by suspension-feeding on toxic diatoms, are the main vectors of the toxin to humans, yet they appear to suffer only minor (Jones et al 1995) or no toxic effects. Shellfish containing > 20 µg DA g -1 tissue wet weight are considered unsafe for human consumption (Wright et al 1989).…”