Wind dispersal differences between rotifer cryptic species: a proof of principle from a wind tunnel experiment

Abstract

Wind is expected to be one of the main vectors of passive dispersal for small zooplankters between discrete, unconnected habitats. However, little is known about the differences in the dispersal capacity of species in relation to their propagule traits. Here we assessed the effect of volume and weight of diapausing eggs and substrate granulometry on the dispersal departure propensity of two differently body-sized rotifer species belonging to the Brachionus plicatilis complex using a wind tunnel experiment. Diapausing eggs of the larger species were also larger but, counterintuitively, were lifted by the wind to a greater extent than those of the smaller one. Further, diapausing eggs on the finer substrate were more exposed to the wind than those over the coarser one, and therefore higher departure rates were observed in the former. Overall, results show that wind is a relevant dispersal vector for the rotifers of the B. plicatilis species complex, with egg morphological traits and substrate granulometry being important factors modulating their dispersal. This study is a proof of concept for the departure phase of dispersal. Further studies on transfer and settlement phases are needed to get a complete picture of the dispersal potential of these organisms.