Uptake and depuration of paralytic shellfish toxins in the green‐lipped mussel, Perna viridis: A dynamic model

Abstract

Uptake and depuration of paralytic shellfish toxins in the green-lipped mussel, Perna viridis, were investigated by exposing the mussels to dinoflagellates (Alexandrium tamarense, ACTI01) under laboratory conditions for 8 d, then depurating them in clean seawater for 14 d. First-order linear differential equations were set up for five tissue compartments: Viscera, gill, hepatopancreas, adductor muscle, and foot. The solutions to these equations were used to fit the experimental data. We then estimated the parameters governing the model, which depend on the elimination rate from each compartment and the transfer coefficient between compartments. An assumption of the model is that the gills transport the dinoflagellates directly to the mouth and then to the viscera, where the ingested cells are broken down, releasing the toxins. The toxins absorbed are transferred to other tissues. During the uptake phase, the transfer coefficients from viscera to gill, hepatopancreas, adductor muscle, and foot were 0.03, 0.24, 0.01, and 0.004 per day, respectively. During the depuration phase, the transfer coefficients were 0.01, 0, 0.01, and 0.003 per day, respectively. In terms of the anatomical distribution of N-sulfocarbamoyl-11-hydroxysulfate (C2) toxins in various tissues, viscera and hepatopancreas contained the highest percentages (47-74% and 8-41%, respectively). Together, these two tissue compartments accounted for 71 to 96% of all C2 toxins present. The biokinetic model allows a quantitative prediction of C2 toxins in whole ussel as well as individual tissue compartments based on the density estimates and toxin load of dinoflagellate cells in the surrounding waters over time.

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

“…Whether DA exchange was important in mussels is not clear. Exchange of DA and DSTs between tissues was found to be negligible in P. maximus (Blanco et al, 2002a) and M. galloprovincialis (Blanco et al, 2007) respectively, whereas considerable transfer of PSTs from the viscera to four other tissues occurred in green mussels (Perna viridis) during toxification and, to a lesser extent during the depuration phase (Li et al, 2005).…”

“…Examination of temporal changes in the anatomical distribution of toxins has been proposed as a valuable indicator of the timing of bloom initiation and termination (Bricelj and Shumway, 1998), and is also useful in the development of predictive toxin kinetics models (e.g. Blanco et al, 2002a;Li et al, 2005).…”

Exposure to the Neurotoxic Dinoflagellate, Alexandrium catenella, Induces Apoptosis of the Hemocytes of the Oyster, Crassostrea gigas

“…These toxins were demonstrated to be highly accumulated in oysters that feed on dinoflagellates [17]. Globally, such paralytic shellfish toxin (PST) producing species negatively affect the clearance rate, the feeding and digestive capacity of exploited bivalves [18,19,20,21,22].…”

Uptake and elimination of brevetoxin in the invasive green mussel, Perna viridis, during natural Karenia brevis blooms in southwest Florida

“…Previously exposed bivalves have shown increased resistance and reduced sensitivity to HAB exposure compared to unexposed populations (Shumway and Gainey, 1992). While P. viridis experiences harmful algal blooms in their native range (Gacutan et al, 1984(Gacutan et al, , 1985Choi et al, 2003;Li et al, 2005;Montojo et al, 2012), exposure to a new toxin may cause reduced physiological function and could cause the widespread mortality observed in southwest Florida. Leverone et al (2007) observed decreased clearance rates in juvenile P. viridis during short term exposure to K. brevis indicating reduced feeding, which may turn lethal if conditions persist.…”