Polypodium hydriforme is a parasitic cnidarian that develops within the eggs of acipenseriform fish in the Old and New Worlds. Currently regarded as monotypic, P. hydriforme has been studied largely in the context of caviar production in Russian sturgeon species. We report the first robust epidemiological study of P. hydriforme in North American acipenseriform fish. We sampled infection prevalences (in 2017 and 2018) and inten...

In the northern hemisphere, glacial periods have had profound and lasting effects on the population genetics of numerous species, with founder effects often persisting for many generations in formerly glaciated regions. We found an unusual example of this in the freshwater bryozoan Cristatella mucedo , which showed regional differences in haplotype diversity with relatively low levels of haplotype diversity in northern Europe...

Temporal changes in the genetic structure of populations of the freshwater bryozoan Cristatella mucedo were investigated by genotyping colonies at five microsatellite loci. Colonies were collected from five different locations over time periods ranging from 1 month to 5 yr. Our findings identified substantial within‐site genetic changes, both within and between years, that were not consistent with variation produced by sexual...

In spite of increasing interest in metapopulation dynamics, the genetic consequences of a metapopulation structure remain poorly understood. Here we examine the metapopulation genetic structure of the colonial, facultatively sexual freshwater bryozoan Cristatella mucedo , in the Thames basin of southern England, UK. Populations from nine sites were sampled and colonies genetically characterized using random amplified polymorph...