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Abstract A hallmark of biological invasion is the rapid reproduction of invasive species. However, we still do not have an adequate understanding of how fluctuations in environmental factors affect the reproduction of invasive species, particularly in estuarine habitats. In this study, we evaluated the reproduction of the Gulf toadfish Opsanus beta and its relationships with temperature and rainfall in the Paranaguá estuary, a subtropical region in southern Brazil. This species was likely introduced into the Brazilian ecosystems through the discharge of ballast water. Since invasion, which was first reported in port areas, the species has rapidly spread along the Brazilian coast line. We collected specimens monthly from October 2011 to September 2012 and from October 2019 to September 2020, to give us insight into the seasonal and temporal changes in the reproduction of this species. We found that O. beta population uses the estuary throughout its life cycle, including during spawning. Females and males spawned throughout almost the entire sampling period and spawning was specified as partially. Peak reproductive activity occurred in periods of lower temperature and was also related to rain. The length of first maturation in females (10cm) was considered early, indicating reproductive activity in smaller individuals. Our results demonstrate that the reproductive strategy used by the invasive species supports its ability to successfully colonize new environments.

Abstract Background The increasing number of dengue cases worldwide implies a greater exposure of at-risk groups, such as pregnant women. DENV infection during pregnancy has been increasingly associated with unfavorable outcomes, but the evolution of the disease and its clinical outcomes remain unclear. The objective of this study was to characterize dengue cases in reproductive aged women by comparing the development of the disease in pregnant and non-pregnant women. Methods A population based retrospective cohort study that used data reported in the Brazilian Mandatory Notifiable Diseases Information System from 2016 to 2019 in Paraná, Brazil. We compared sociodemographic, clinical, and laboratory variables between pregnant and non-pregnant women. Hospitalization and disease severity classification (Dengue, Dengue with warning signs, Severe Dengue) were considered outcome variables. Results The two groups had differences in the year of notification, age distribution, and region of residence. Laboratory investigation was more frequent among pregnant women, and DENV-2 prevailed in both groups. The risks of hospitalization and development of Severe Dengue were higher in pregnant women. There were no deaths observed among pregnant women. Conclusion This study identified pregnancy as a risk factor for an increase in the severity of DENV infection. It reinforces the importance of identifying early signs of complication, close monitoring, and adequate treatment for pregnant women.