Lack of behavioral effect of surgical mask leachate on the Asian shore crab Hemigrapsus sanguineus: Implications for invasion success in polluted coastal waters.

The COVID-19 pandemic generated a new source of plastic mass pollution, i.e. surgical masks, that preferentially accumulate in intertidal environments. Made of polymers, surgical masks are likely to leach additives and impact local intertidal fauna. As typical endpoints of complex developmental and physiological functions, behavioral properties are non-invasive key variables that are particularly studied in ecotoxicological and pharmacological studies, but have, first and foremost, adaptive ecological significance. In an era of ever-growing plastic pollution, this study focused on anxiety behaviors, i.e. startle response, scototaxis (i.e. preference for dark or light areas), thigmotaxis (i.e. preference for moving toward or away from physical barriers), vigilance and level of activity, of the invasive shore crab Hemigrapsus sanguineus in response to leachate from surgical masks. We first showed that in the absence of mask leachates H. sanguineus is characterized by a short startle time, a positive scototaxis, a strong positive thigmotaxis, and an acute vigilance behavior. Specifically, a significantly higher level of activity was observed in white areas, in contrast to the lack of significant differences observed in black areas. Noticeably, the anxiety behaviors of H. sanguineus did not significantly differ after a 6-h exposure to leachate solutions of masks incubated in seawater for 6, 12, 24, 48 and 96 h. In addition, our results were consistently characterized by a high inter-individual variability. This specific feature is discussed as an adaptive behavioral trait, which - through the observed high behavioral flexibility - increases H. sanguineus resilience to contaminant exposures and ultimately contribute to its invasion success in anthropogenically-impacted environments.

Pulmonary Paragonimiasis: A Case Series.

Paragonimiasis contributes to significant foodborne zoonosis worldwide. The major mode of transmission in humans is by consumption of uncooked or undercooked crabs and crayfish harbouring Paragonimus metacercariae. It begins with symptoms like fever and lower respiratory involvement from a few months to a year, mimicking those of tuberculosis and leading to diagnostic delay. Here, we report two cases of paragonimiasis during a period of nine months. Both cases presented with symptoms of productive cough with rusty sputum, chest pain, along with eosinophilia, and pleural effusion and had a history of consumption of smoked crab from the local river. The diagnosis was established by microscopic demonstration of Paragonimus ova in the sputum. They were treated with praziquantel and recovered. Indeed, it is challenging to diagnose paragonimiasis due to the lack of its specific symptoms but should be considered in the differential diagnosis of eosinophilia and pleural effusion in such lung diseases. Keywords: case reports; eosinophilia; paragonimiasis; pleural effusion.

Recovery of ghost crabs metapopulations on urban beaches during the Covid-19 "anthropause".

The majority of government authorities initially responded to COVID-19 pandemic by declaring lockdown to facilitate social distancing and minimize virus spreading. This period termed "anthropause" provided a unique opportunity to evaluate the recovery of wildlife in the absence of stressors on urban ecosystems. We assessed whether the anthropause associated with beach closures during the COVID-19 pandemic resulted in repopulation of the Atlantic ghost crab Ocypode quadrata (Fabricius, 1787) on urban beaches. For this purpose, we compiled a historic dataset (2013-2019) of the ghost crab density and performed biweekly burrow measurements from June/2020 to May/2021. Recovery of ghost crab metapopulation during the lockdown occurred even in more human-modified beaches. Burrow abundance significantly increased in urban sectors, but not in control site along with the time of pandemic. The reduction in the mean burrow opening diameter during this period evidenced that young metapopulation have thrived on urban beaches when recreational activities ceased. Our results show that urban beaches should not be exclusively managed for recreational purposes. Initiatives with a focus on wildlife conservation including spatial-temporal controlled beach closures may increase the biodiversity resilience.