Levels and chemical speciation of arsenic in polychaetes: a review

Abstract

Relatively few studies have characterized basal content and variability of arsenic in polychaetes, despite the potential importance of this element as a pollutant of marine environments. Even less have investigated the chemical speciation of arsenic, occurring as inorganic and organic forms, which reflect a different biological reactivity of the element. In the present paper we integrate existing literature with new data in order to summarize the status quo on arsenic bioaccumulation in polychaetes. We consider species with different trophic habits, phylogenetic relationships, geographic distribution and ecology. Reported data indicate a high variability in arsenic concentration with levels ranging from <1 μg·g−1 to more than 2500 μg·g−1 in different species; some additional species analyzed in this work confirm species‐specific characteristics which are not easily explained by biological or ecological factors. The profile of arsenic compounds in polychaetes is different to that of most aquatic organisms. Typically this element occurs in non‐toxic organic forms, however several polychaete species have been shown to accumulate relatively toxic molecules and subsequently biotransform them by processes such as methylation. Conclusions from the literature review reveal a complex array of arsenic actions in the environment and suggest a biological role of this element in the life history of some polychaete species.

Arsenic speciation in polychaetes (Annelida) and sediments from the intertidal mudflat of Sundarban mangrove wetland, India

“…The maximum DMA concentration in sediments was recorded at site S 10 (0.06 mg kg -1 ). However, the DMA is consistently present as the most important intermediates and degradation products in all polychaetes and the maximum concentrations were observed in L. notocirrata (0.41 mg kg -1 dw) and G. sootai (0.39 mg kg -1 dw) at sites S 4 and S 2 respectively confirming a rapid transformation of arsenic in these polychaetes as reported by Fattorini et al (2005). The presence of DMA might suggest both the degradation of more complex arsenic compounds (i.e., arsenosugars) accumulated from phytoplankton algae or the methylation of inorganic arsenic usually present in abiotic matrices such as seawater and sediments (Notti et al, 2007).…”

“…The results demonstrate the capacity of the four benthic polychaete species to accumulate the As and its different species which might be ascribed to species-specific characteristics and inherent peculiarities in arsenic metabolism (Fattorini et al, 2005). The unusual prevalence of As III and other less innocuous compounds (such as DMA and As-PO 4 ) was encountered in the sediment ingester G. sootai and detritivore L. notocirrata which is the most interesting aspect of the work.…”

Arsenic toxicity in a sediment-dwelling polychaete: detoxification and arsenic metabolism

“…Most polychaetes exhibit arsenic concentrations in the range found for other marine organisms (Fattorini et al 2005;. However, some polychaetes can accumulate relatively high arsenic concentrations compared to other marine organisms, being extremely high in Tharyx marioni (Gibbs et al 1983) and some tissues of Sabella spallanzanii (Fattorini and Regoli 2004).…”

“…Natural populations of this polychaete do not present conspicuously high concentrations of arsenic in their tissues (Fattorini et al 2005; but the few studies carried out in this species have found an unusual pattern of arsenic compounds (Geiszinger et al 2002a). Arenicola marina accumulates a relatively high proportion of arsenic in the inorganic form (75%) and upon exposure to arsenic in seawater, most of the accumulated arsenic is accumulated as arsenite, the form of arsenic which is considered toxic and potentially carcinogenic, with a small quantity accumulated as DMA suggesting a limited biomethylation capacity in this species (Geiszinger et al 2002a).…”

Hyperaccumulation of vanadium in the Antarctic polychaete Perkinsiana littoralis as a natural chemical defense against predation

“…ularly high concentrations of various trace metals have been shown in tissues of certain polychaetes (Gibbs et al 1981;Ishii et al 1994;Fattorini et al 2005;Sandrini et al 2006), and various hypotheses on the biological role of these elements still represent a stimulating field of investigation.…”