Toxicological response of the symbiotic sea anemone Aiptasia pallida to butyltin contamination

Abstract

This study investigates the fate of tributyltin (TBT), a widespread biocide mainly used in antifouling paints, and of its derivative dibutyltin (DBT) in sea anemones Aiptasia pallida exposed via water or food. Experiments were conducted on both symbiotic and aposymbiotic (lacking zooxanthellae) individuals under a 12 h light: 12 h dark photoperiod or in total darkness. TBT and DBT concentrations in the animal and vegetal compartments were measured over 24 h, 30 h, 5 d. 7 d and 28 d periods. Uptake and accumulation from seawater, mainly as DBT due to natural degradation of TBT, was found to be dependent on the presence and illumination of zooxanthellae. DBT concentratlons in symbiotic anemones exposed to light were roughly twlce those found in individuals maintained ~n total darkness, and about 10 times greater than in aposymbiotic anemones. A peak accumulation in animal and vegetal tissues occurred after 24 to 4 8 h in all symbiotic anemones. A 28 d exposure of symbiotic anemones to a nominal 50 ng TBT 1-' resulted in butyltin concentrations under 1 ng mg-' dry mass. Accumulation most probably occurs through butyltln uptake by zooxanthellae, while their expulsion from the host acts as a depuration process. The presence of zooxanthellae also seems determinant in the regulation and degradation of butyltin ingested with food. Daily ingestion of TBT-contaminated mussel tissue led to sequential debutylation into DBT and monobutyltin (MBT) in symbiotic A . pallida but not in aposymbiotic ones. Over 7 d. aposymbiotic anemones showed close to 100% retention of ingested TBT, while all butyltin species remained undetected in symbiotic anemones. After 28 d, the retention efficiency was -68% in symbiotic anemones in which -59% of the butyltin was in the form of DBT

Effect of Nanoparticles on DMS Consumption and DMSP Concentration in Aiptasia pallida

“…Tentacle retraction and in other more extreme cases loss of tentacles (which was only observed in cAg NP) may have been due to a greater accumulation of NPs in the symbiont due to its greater tolerates [12]. This is reinforced by observations of retracted tentacles to tributyltin (a biocide in anti-fouling paint) in symbiotic anemones compared to no retraction of tentacles in aposymbiotic anemones [20] suggested that the host anemones are able to reverse translocate tributylin into the its symbionts, therefore, the loss of tentacles is likely to be a "last resort" mechanism, in which majority of the NPs are reverse translocated from the host to tissue into the symbiont (Figure 7). Furthermore, retracted or loss of tentacles also reduces its surface area.…”

Biotransformation of Tributyltin to Tin in Freshwater River-Bed Sediments Contaminated by an Organotin Release

“…Such properties of organotin compounds also render TBT an ecological risk to nontarget organisms exposed to TBT in aquatic environments, such as in harbors and areas that service boats ( − ). Dissolved-phase concentrations of TBT less than 100 μg/L can cause growth and reproductive problems in mussels and oysters, and exposure to aquatic invertebrates is believed to cause endocrine disruption, such as imposex and intersex in gastropods ( , ).…”