Early-stage invasive apple snails exhibit elevated ROS levels and enhanced oxidative stress defenses compared to non-invasive species

Abstract

Understanding why some animal species become highly successful invaders while closely related ones do not is fundamental to invasion biology. In this study, we investigated the antioxidant defense system of 2 closely related apple snail species of a single genus but with contrasting ecological success: Pomacea canaliculata, a widespread invader, and P. scalaris, a non-invasive species. We focused on their most vulnerable life cycle stages, analyzing the antioxidant capacity of eggs, and exploring maternal investment in carotenoid antioxidants and their influence on newly hatched snails. Our results revealed a strong positive correlation between maternal carotenoid investment and egg antioxidant capacity, with higher levels in P. canaliculata. Furthermore, newly hatched snails of P. canaliculata exhibited increased total antioxidant capacity and increased activities of the ROS-scavenging antioxidant enzymes, superoxide dismutase, glutathione reductase, and catalase compared to P. scalaris. Additionally, P. canaliculata cells exhibited higher basal levels of reactive oxygen species (ROS). The robust antioxidant defense system found in P. canaliculata would play a role in tolerating elevated ROS levels and mitigating oxidative damage during early development. Overall, our findings highlight the potential role of antioxidant defenses and provide insights into one of the mechanisms underlying the success of certain invasive species.