Persistent Contamination of Octopuses and Mussels with Lipophilic Shellfish Toxins during Spring Dinophysis Blooms in a Subtropical Estuary.

Luiz Mafra,Hajime Uchida,Vanessa Bonilauri,Daiana Lopes,Toshiyuki Suzuki

doi:10.3390/md13063920

Luiz Mafra, Hajime Uchida + Show 3 more

Open Access

https://doi.org/10.3390/md13063920

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Abstract

This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in 2012 and 2013, cells of Dinophysis acuminata complex were always present, sometimes at relatively high abundances (max. 1143 cells L−1), likely the main source of okadaic acid (OA) in the plankton (max. 34 ng L−1). Dinophysis caudata occurred at lower cell densities in 2013 when the lipophilic toxins pectenotoxin-2 (PTX-2) and PTX-2 seco acid were detected in plankton and mussel samples. Here, we report for the first time the accumulation of DSTs in octopuses, probably linked to the consumption of contaminated bivalves. Perna perna mussels were consistently contaminated with different DSTs (max. 42 µg kg−1), and all octopuses analyzed (n = 5) accumulated OA in different organs/tissues: digestive glands (DGs) > arms > gills > kidneys > stomach + intestine. Additionally, similar concentrations of 7-O-palmytoyl OA and 7-O-palmytoly dinophysistoxin-1 (DTX-1) were frequently detected in the hepatopancreas of P. perna and DGs of O. vulgaris. Therefore, octopuses can be considered a potential vector of DSTs to both humans and top predators such as marine mammals.

Highlights

Accumulation of Diarrhetic Shellfish Toxins (DSTs) in bivalve mollusks has caused expressive economic losses and human intoxication outbreaks in different parts of the globe
Some Dinophysis species may produce another group of lipophilic shellfish toxins (LSTs), the pectenotoxins (PTXs), which are commonly found in plankton and bivalve tissues during Diarrhetic Shellfish Poisoning (DSP) events and may interfere with mice bioassay (MBA) results, the toxicity of these polyether-lactones to humans is uncertain because they are hepatotoxic to mice by intra-peritoneal injection but not by oral administration [9]
The calculated detection limits were 0.011, 0.018 and 0.030 ng mL−1 for okadaic acid (OA), DTX-1 and PTX-2, respectively. This is the first report of DST accumulation in the common octopus (O. vulgaris), probably linked to the consumption of contaminated bivalves during periods when Dinophysis spp. were persistently present at moderate cell abundances in the water

Summary

Introduction

Accumulation of Diarrhetic Shellfish Toxins (DSTs) in bivalve mollusks has caused expressive economic losses and human intoxication outbreaks in different parts of the globe (reviewed in Reguera et al [1]). The causative toxins, okadaic acid (OA) and its relative compounds, the dinophysistoxins (DTXs), can provoke phosphatase inhibition leading to DSP symptoms, and immunotoxicity, genotoxicity and cytotoxicity to many cell types, (reviewed in Valdiglesias et al [6]), and even tumor formation upon chronic exposure [7]. Okadaic acid and their analogs, DTX-1 and DTX-2, are produced by 10 species of the dinoflagellate. The occurrence of DSTs and other LSTs was evaluated in multiple tissues/organs of both mussels and octopuses to assess the risk for chronic LST exposure among human consumers and marine predators

Cell Abundance and Toxin Concentration in the Plankton

Toxin in Mussels and Octopuses

Field Sampling

Toxin Analysis

Conclusions