Dear Spongers, a new contribution to the population genetics of alien sponges by my team The symbiont side of symbiosis: do microbes really benefit? Open Access at http://link.springer.com/article/10.1007/s00227-016-2862-6 <http://link.springer.com/article/10.1007/s00227-016-2862-6?wt_mc=internal.event.1.SEM.ArticleAuthorIncrementalIssue> Best Iosune