The Common Sunstar Crossaster papposus—A Neurotoxic Starfish

Abstract

Saxitoxins (STXs) are a family of potent neurotoxins produced naturally by certain species of phytoplankton and cyanobacteria which are extremely toxic to mammalian nervous systems. The accumulation of STXs in bivalve molluscs can significantly impact animal and human health. Recent work conducted in the North Sea highlighted the widespread presence of various saxitoxins in a range of benthic organisms, with the common sunstar (Crossaster papposus) demonstrating high concentrations of saxitoxins. In this study, an extensive sampling program was undertaken across multiple seas surrounding the UK, with 146 starfish and 5 brittlestars of multiple species analysed for STXs. All the common sunstars analysed (n > 70) contained quantifiable levels of STXs, with the total concentrations ranging from 99 to 11,245 µg STX eq/kg. The common sunstars were statistically different in terms of toxin loading to all the other starfish species tested. Two distinct toxic profiles were observed in sunstars, a decarbomylsaxitoxin (dcSTX)-dominant profile which encompassed samples from most of the UK coast and an STX and gonyautoxin2 (GTX2) profile from the North Yorkshire coast of England. Compartmentalisation studies demonstrated that the female gonads exhibited the highest toxin concentrations of all the individual organs tested, with concentrations >40,000 µg STX eq/kg in one sample. All the sunstars, male or female, exhibited the presence of STXs in the skin, digestive glands and gonads. This study highlights that the common sunstar ubiquitously contains STXs, independent of the geographical location around the UK and often at concentrations many times higher than the current regulatory limits for STXs in molluscs; therefore, the common sunstar should be considered toxic hereafter.

Novel Methodologies for Providing In Situ Data to HAB Early Warning Systems in the European Atlantic Area: The PRIMROSE Experience

“…These production areas may be different from those that are currently regularly monitored. Knowing the toxin levels in those vectors, offers the potential to apply measures to prevent human and animal (Dean et al, 2021) intoxications. The information gathered could also guide the design of future monitoring plans.…”

Marine natural products

“…716 A survey of starfish and brittlestars collected from various sites around the UK has found common sunstars to always contain quantifiable levels of saxitoxins, with high to very high levels concentrated in female gonads. 717 The structures and biological activities of sea cucumber-derived triterpene glycosides (2017–2021) have been reviewed. 718 Mining the genome of Apostichopus japonicus led to the identification of 30 enzymes responsible for saponin biosynthesis.…”