Effects of lead pollution on Ammonia parkinsoniana (foraminifera): ultrastructural and microanalytical approaches

Abstract

The responses of Ammonia parkinsoniana (Foraminifera) exposed to different concentrations of lead (Pb) were evaluated at the cytological level. Foraminifera-bearing sediments were placed in mesocosms that were housed in aquaria each with seawater of a different lead concentration. On the basis of transmission electron microscopy and environmental scanning electron microscopy coupled with energy dispersive spectrometer analyses, it was possible to recognize numerous morphological differences between untreated (i.e., control) and treated (i.e., lead enrichment) specimens. In particular, higher concentrations of this pollutant led to numerical increase of lipid droplets characterized by a more electron-dense core, proliferation of residual bodies, a thickening of the organic lining, mitochondrial degeneration, autophagosome proliferation and the development of inorganic aggregates. All these cytological modifications might be related to the pollutant-induced stress and some of them such as the thickening of organic lining might suggest a potential mechanism of protection adopted by foraminifera.

Response of a kleptoplastidic foraminifer to heterotrophic starvation: photosynthesis and lipid droplet biogenesis

“…They are known as the primary carbon storage in foraminifera (Hottinger & Dreher, 1974, Leutenegger, 1977, Hottinger, 1982, Pawlowski et al, 1995. Similarly to residual bodies, the accumulation of lipid droplets in foraminifera is a known symptom of environmental stress, such as heavy metal toxicity and oil pollution (Morvan et al, 2004, Le Cadre & Debenay, 2006, Frontalini et al, 2015, Frontalini et al, 2018. Our results show that starvation can be another factor triggering lipid droplet accumulation.…”

Holocene foraminiferal and geochemical records in the coastal karst dolines of Cres Island, Croatia

“…Most studies indicate that high Pb concentrations in marine sediments result in low diversity of fauna and the predominance of opportunistic species, as well as an increase in the abnormalities of foraminiferal tests. FRONTALINI et al (2015) exposed Ammonia parkinsoniana specimens, cultured in mesocosms, to various concentrations of Pb in sediments. Specimens showed cytological modifications that might be related to pollutant-induced stress.…”

Assessing the Cadmium Effects on the Benthic Foraminifer Ammonia cf. parkinsoniana: An Acute Toxicity Test

“…parkinsoniana were placed on Petri dishes covered with NSW. This taxon was chosen to have a comparison with previous published papers [25,26,28]. In fact, this taxon has been selected, in previous studies, to test the effects of lead [25], mercury [26] and a set of nanoparticles (titanium dioxide, polystyrene and silicon dioxide) [28].…”

“…Culture and mesocosms experiments have been applied to study the effects induced by different heavy metals at species' and at foraminiferal assemblages' level, respectively. Despite the simplicity and versatility of these experiments, very few studies have been published on the noxious effect that a single pollutant might trigger in the physiology of the foraminiferal cell in terms of tolerance, growth, reproduction and/or survival (e.g., [4,19,[21][22][23][24][25][26]), and even more limited is the number of publications on ultrastructural and physiological changes induced by exposure to pollutants (e.g., [20] for review) or to Cd exposure [4,24].…”