Organisms have evolved internal time tracking systems, defined as circadian clocks, to synchronise their physiology and behaviour with regularly fluctuating environmental parameters. Circadian clocks also regulate when  some specific activities (such as feeding and habitat exploration) should be performed, in order to limit competitive interactions among individuals. Recent theoretical models have actually emphasised the role of interspecific competition in driving the evolution of circadian rhythms. In this view, sympatric competitors could have evolved different temporal patterns of activity to coexist in the same environment.

Biological invasions are one of the main drivers of biodiversity loss across the world. Coastal, freshwater, and brackish habitats are among the most vulnerable habitats to invasions. The arrival of a newly introduced species usually amounts to the arrival of a new competitor and/or predator, with which the native species can establish exploitative and interference competitive interactions.

The aim of the present project is to determine if invasive alien species can affect the circadian physiological and behavioural rhythms of native species and how much plastic is the circadian clock of native species to preserving fitness and survivorship. To do so, we selected two native species occurring in Po River Delta, the Mediterranean shore crab Carcinus aestuarii and the Mediterranean killifish Aphanius fasciatus, and two invasive alien species, the Atlantic blue crab Callinectes sapidus and the Eastern mosquitofish Gambusia holbrooki, which proved to be competitors of the Italian native ones. 

This project was funded by he European Union- Next Generation EU, Missione 4 Componente C2 Investimento 1.1

Progetto P20222E4CY  -  CUP F53D23008150001