Effects of chemical pollutants on reproductive and developmental processes in Italian amphibians

Abstract

It is a widely held belief that environmental contaminants contribute to the decline of amphibian populations. By spending most of their early life in water and later stages on the land, amphibians face a constant risk of exposure to pesticides and other chemical pollutants in both aquatic and terrestrial environments. This review presents an overview of the studies carried out in Italian amphibians to highlight hazardous effects of bioaccumulation of chemical pollutants in juveniles and adults in various contaminated environments. Further, the studies in the laboratory setting assessing the effects of chemical pollutants on reproductive and developmental processes are reported. These studies and their relative references have been summarized in a tabular form. Three prominent contaminant groups were identified: herbicides, insecticides, and fungicides; and only a few works reported the effects of other chemical pollutants. Each pollutant group has been delegated to a section. All through the literature survey, it is seen that interest in this topic in Italy is very recent and sparse, where only a few anuran and caudata species and only some chemical pollutants have been studied.

An integrated approach to assess the sublethal effects of colloidal gold nanorods in tadpoles of Xenopus laevis

“…This is a relevant issue, since amphibians are declining at an alarming rate worldwide; previous studies have reported reductions in amphibian populations of 53% since the 1950s just for Western Europe, and of 60% and 54% in South and North America (Khan and Law, 2005;IUCN, 2020). Accumulating evidences suggest environmental contamination as a major cause for such declines (Pinelli et al, 2019). Considering that AuNR aggregate and agglomerate when in contact with natural aqueous media it is likely that, once released into the aquatic environment, will form large structures that will deposit in the sediments (Surette and Nason, 2018).…”

Heavy Metals Assessment in the Medjerda River Basin (Northeastern Algeria): A Preliminary Water Analysis and Toad Skin Biopsy

“…As kown, all toxic and trace metals interfere in the normal functioning of structural proteins, enzymes, and nucleic acids by binding them. But, recently, in amphibian evidence of metabolic and enzyme activities alterations, morphophysiological changes were reported after increasing levels of Pb, Fe and/ or Cu and Zn alone or combined (Pinelli et al 2019;Chagas et al 2020).…”

“…To study the effect of toxic and trace metals examined on biota we chosen amphibian for their key ecological role as bioindicator (Niethammer et al 1985;Ben Hassine and Escorzia 2017;Guerriero et al 2018b;Pinelli et al 2019). In particular, for this project we collected skin biopsy from male toads because anatomically they are very easy to identify and to complete gender detoxification analysis of cytochrome aromatase p450 aromatase and glutathione S-transferase in Bufo spinosus by Real Time-PCR (studies in progress).…”

“…Several researchers have attempted to document the impacts of metal buildup in amphibians both in captivity (Herkovits and Helguero 1998;James and Little 2003;D'Errico et al 2018;Guerriero et al 2018b;Pinelli et al 2019), and in field conditions (Demichelis et al 2001;Borkin and Flyaks 2004;Fenoglio et al 2006;Gavrilović et al 2020). Other studies have reported deformity, delay in metamorphosis, reduced flight response and altered interactions with predators in amphibians after exposure to metals in water (Chen et al 2009;James and Semlitsch 2011;Zocche et al 2013;Chagas et al 2020).…”

“…The spiny toad Bufo spinosus (Amphibia: Anura) was chosen for this purpose because, it is present in Algeria and in the wettest and most temperate zones in North Africa (Tlidjane et al 2019). The choice of an amphibian was based on their key ecological role in the trophic networks as prey or predators in a wide range of ecosystems (Niethammer et al 1985;Ben Hassine and Escorzia 2017;Pinelli et al 2019). In fact, frogs usually use their own skin as a secondary respiratory surface, which is permeable to endogenous and exogenous substances whose potential harmful effects are contrasted by keratins.…”