Evaluating the toxicity of estetrol, 17α-ethinylestradiol, and their combination with drospirenone on zebrafish larvae: A behavioural and proteomic study.

Objective: To characterise and compare the toxicity of estetrol (E4) and 17α-ethinylestradiol (EE2), and their respective mixture with the progestin drospirenone (DRSP) in zebrafish (Danio rerio) embryos.

Methods: Zebrafish embryos were exposed to E4, EE2, DRSP, E4+DRSP, and EE2+DRSP in a fish embryo acute toxicity (FET) test. A second test examined behavioural responses and, using label-free proteomics, identified changes in protein expression in response to hormonal treatments, across a range of concentrations, including those that are considered to be environmentally relevant.

Estetrol/drospirenone versus 17α-ethinylestradiol/drospirenone: An extended one generation test to evaluate the endocrine disruption potential on zebrafish (Danio rerio).

Combined oral contraceptives, comprising of both an oestrogen and a progestin component, are released in aquatic environments and potentially pose a risk to aquatic wildlife by their capacity to disrupt physiological mechanisms. In this study, the endocrine disruptive potential of two mixtures, 17α-ethinylestradiol (EE2), a synthetic oestrogen, or estetrol (E4), a natural oestrogen, with the progestin drospirenone (DRSP) have been characterised in three generations of zebrafish, according to an adapted Medaka Extended One Generation Reproduction Test. Zebrafish (Danio rerio) were exposed to a range of concentrations of EE2/DRSP and E4/DRSP (∼1×, ∼3×, ∼10× and ∼30× predicted environmental concentration, PEC).

Morphodynamics of a composite sand-cobble beach in response to extratropical cyclone Fiona and seasonal wave variability.

Climate change is driving higher coastal water levels, and models project accelerated future sea-level rise and coastal storm intensification. These dynamics paired with anthropogenic coastal alterations will drive drastic coastal change worldwide. Composite beaches with mixed sediment sizes warrant detailed study as these exhibit complex morphodynamics in response to changing hydrodynamics due to the distinct transport thresholds of different sediment types.

Gut microbiota of an Amazonian fish in a heterogeneous riverscape: integrating genotype, environment, and parasitic infections.

A number of key factors can structure the gut microbiota of fish such as environment, diet, health state, and genotype. , an Amazonian cichlid, is a relevant model organism to study the relative contribution of these factors on the community structure of fish gut microbiota. has well-studied genetic populations and thrives in rivers with drastically divergent physicochemical characteristics.