Differences in the gonadal cycle between two ascidians species, Ascidiella aspersa and Ciona robusta, help to explain their invasion success in a cold temperate port

GIACHETTI, C; TATIÁN, M; SCHWINDT, E

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2022

0722-4060

Invasive ascidians are one of the most abundant components of the fouling communities of artificial structures. Ascidians? toleranceto pollution, salinity, and temperature differences, alongside high reproductive and growth rates, facilitate their globalspread and establishment. However, the influence of ascidians? reproductive ecology on their abundance in cold temperateareas is poorly studied. In cold regions, ascidians? reproductive ecology fluctuates markedly, depending on environmentalfactors. This might lead to differences in the gonadal cycle of invasive ascidians between the native and invaded area. Ourstudy investigates the gonadal cycle of two invasive ascidian species, Ascidiella aspersa and Ciona robusta, and discussestheir potential role in the invasion success in a cold temperate port. Using histological analysis, the gonadal cycle of eachspecies was compared throughout the year and among seasons. Only A. aspersa showed a reproductive cycle different fromtheir native range, with mature gonads during spring and summer. Ciona robusta showed mature gonads throughout the year,similar to its native range. These results were unexpected, as the larger abundance of A. aspersa is constant throughout theyear, whereas the less abundant C. robusta shows a peak during autumn. Future research should explore how interspecificcompetition and predation interact with reproductive ecology, shaping the abundance of invasive ascidians. Considering thehigh connectivity of southern South America with Antarctica and the future scenarios of global change, knowing how thebiology of invasive species change in their invasive range is key to advance and implement management strategies.