Liza ramada Juveniles after Exposure to the Toxic Dinoflagellate Vulcanodinium rugosum: Effects on Fish Viability, Tissue Contamination and Microalgae Survival after Gut Passage

Abstract

Pinnatoxins (PnTX) and Portimines (Prtn), two toxins produced by the benthic dinoflagellate Vulcanodinium rugosum, are known to be lethal to mice after intraperitoneal or oral administration. They are also known to accumulate in shellfish such as mussels and clams, but their effect on fish and the upper food chain remains unknown. In this work, juveniles of the fish Liza ramada (Mullet) were exposed to a strain of V. rugosum producing PnTX G and Prtn A. The fishes’ viability and contamination were recorded at times interval. Results showed that L. ramada juveniles were able to feed on V. rugosum and that their tissues could be contaminated by PnTX G and Prtn A without impact on fish viability. Furthermore, the microalgae temporary cysts survived and germinated after fish gut passage. This study showed the potential of L. ramada to transfer PnTX and Prtn toxins to the upper food chain and to disseminate V. rugosum in environment.

Artificial Substrates Coupled with qPCR (AS-qPCR) Assay for the Detection of the Toxic Benthopelagic Dinoflagellate Vulcanodinium rugosum

“…The extension of the microalgae distribution area has long been studied [ 28 , 29 , 30 , 31 ]. Recent studies showed that V. rugosum cells could be translocated through ballast water, and that their temporary cysts could survive the passage through the guts of migratory grey mullets Liza ramada or oysters Crassostrea gigas [ 7 , 32 , 33 ]. These species are massively present in Mediterranean lagoons and could thus participate in V. rugosum cells dispersion [ 7 , 32 , 33 , 34 ].…”

“…Recent studies showed that V. rugosum cells could be translocated through ballast water, and that their temporary cysts could survive the passage through the guts of migratory grey mullets Liza ramada or oysters Crassostrea gigas [ 7 , 32 , 33 ]. These species are massively present in Mediterranean lagoons and could thus participate in V. rugosum cells dispersion [ 7 , 32 , 33 , 34 ]. Taken together, the results show the potential of V. rugosum to colonize Mediterranean lagoons and coastal marine ecosystems.…”

“…These toxins can accumulate in shellfish [ 3 , 4 , 5 ] and cause death after oral or intraperitoneal administration to mice [ 6 ]. They were also shown to contaminate mugilid juveniles in high concentrations [ 7 ], which suggests that they could reach higher levels of the fish food web.…”

Harmful Algae Impacting Aquatic Organisms: Recent Field and Laboratory Observations

“…These cysts were able to germinate within 8–22 h after isolation from the faeces and incubation in an enriched seawater culture medium. Bouquet et al recommended further investigations given that finfish may be vectors of pinnatoxins and may affect consumers, especially given that they observed pinnatoxin levels in fish tissues of up to 169.8 µg PnTX G kg −1 , which were above the recommended sanitary level that so far has only been determined for shellfish (23 µg PnTX G kg −1 ) [ 33 , 34 ].…”