Abstract
Prorocentrum lima is a widely distributed and major source of diarrhetic shellfish toxins (DSTs); the ecological impact of diol-estered DSTs (eDSTs) compounds on benthic systems is still inadequate. In this study, the acute toxicity of eDSTs was evaluated in Caenorhabditis elegans, and their accumulation capacity and toxic effects were examined in Mytilus galloprovincialis for an ecological risk assessment. The results indicated that larvae 1 (L1) was more sensitive than larvae 4 (L4) of C. elegans, and the eDSTs in P. lima extract lysate were more toxic than the okadaic acid (OA) standard solution. The lowest LC(50) values were 0.293 and 0.469 μg/mL for L1 and L4, respectively. The growth, productivity, and intestinal permeability of C. elegans were impaired, and the effect of P. lima extract lysate on C. elegans was greater than that of the OA standard solution. The total toxin concentration in the digestive gland of mussels reached 3230 μg/kg, with esterified DSTs accounting for 76.7-97.1% of total toxins and inducing marked oxidative stress. Diol-estered DSTs exert direct toxic effects, including oxidative damage and growth inhibition, while exhibiting a high accumulation potential. This study revealed the toxicity of eDSTs, necessitating a focused investigation to comprehensively assess their toxicological impact and ecological risks.