Pufferfish mortality associated with novel polar marine toxins in Hawaii

Abstract

Fish die-offs are important signals in tropical marine ecosystems. In 2010, a mass mortality of pufferfish in Hawaii (USA) was dominated by Arothron hispidus showing aberrant neurological behaviors. Using pathology, toxinology, and field surveys, we implicated a series of novel, polar, marine toxins as a likely cause of this mass mortality. Our findings are striking in that (1) a marine toxin was associated with a kill of a fish species that is itself toxic; (2) we provide a plausible mechanism to explain clinical signs of affected fish; and (3) this epizootic likely depleted puffer populations. Whilst our data are compelling, we did not synthesize the toxin de novo, and we were unable to categorically prove that the polar toxins caused mortality or that they were metabolites of an undefined parent compound. However, our approach does provide a template for marine fish kill investigations associated with marine toxins and inherent limitations of existing methods. Our study also highlights the need for more rapid and cost-effective tools to identify new marine toxins, particularly small, highly polar molecules.

Marine natural products

“…735 Bioassay-directed fractionation of liver extracts of Hawaiian puffersh Arothron hispidus that had suffered a mass mortality event led to the partial purication of polar molecules such as 1545 as being associated with the sh deaths. 736 Difficulty with purication, combined with only extremely small quantities of toxin (35 mg) and the presence of several related molecules, means the structure shown is somewhat speculative.…”

Projecting Future Climate Change-Mediated Impacts in Three Paralytic Shellfish Toxins-Producing Dinoflagellate Species

“…Termed harmful algal blooms (HABs), these phenomena have been in the spotlight of environmental management for quite some time [ 7 , 8 ], due to their link to a wide variety of environmental issues. These include mass fish and shellfish die-offs [ 9 , 10 ], the degradation of coastal habitats and ecosystem community structure [ 11 , 12 ], the death of marine mammals and seabirds [ 13 ], and outbreaks of human shellfish and finfish poisonings [ 2 , 14 ]. In the marine realm, approximately three hundred of the circa five thousand microalgae species (c. 6%) are known to have the potential to generate HAB events under favorable conditions [ 5 , 15 ].…”

Mortalidad masiva de Canthigaster rostrata (Tetraodontiformes: Tetraodontidae) en la costa del Caribe Sur de Costa Rica

“…Some of the possible causes of death documented in other mass mortality events of tetraodontidae and reef fish include infection by ectoparasite copepods in Diodon maculatus (Sri Lanka) (Kirtisinghe, 1934), paralytic toxins produced by dinoflagellates (Baja California, Mexico) (Ochoa et al 1997), outbreaks of diseases in surgeonfish such as Ctenochaetus striatus (French Polynesia) (Stier et al 2013) and toxicosis (Hawaii), which caused vacuolar changes in the liver of Arothron hispidus and death (Work et al 2017). The artisanal fishing practices in the area were ruled out as potential causes, since the event only affected C. rostrata, which is not a species of commercial interest.…”