Sexual propagation by sponge fragments

Abstract

Top of pageAbstractHabitat fragmentation means that many species occur in discrete populations1, so it is important for sessile species to colonize new areas. It has not been clear how sponges whose larvae disperse over short distances achieve this. Fragments may break off sponges as a result of physical and biological disturbance and are then dispersed by currents and recruited as independent individuals or colonies2,3. Local populations are expected to have high genetic relatedness as a result, but most sponge populations have high levels of genetic variability4,5. We suggest that this discrepancy results from an interaction between fragmentation and sexual reproduction.