Impacts of alien species may change with time but there are few long-term studies of invasions. Here, we present an example of a substantial change in the impact of an alien species that appeared more than a decade after initial invasion. We studied an invasion of zebra mussels (Dreissena polymorpha) into the Hudson River (New York, USA) over a 22 year period (1987–2008) including five years of...

Why organisms diversify into discrete species instead of showing a continuum of genotypic and phenotypic forms is an important yet rarely studied question in speciation biology. Does species discreteness come from adaptation to fill discrete niches or from interspecific gaps generated by reproductive isolation? We investigate the importance of reproductive isolation by comparing genetic discret...

Bdelloid rotifers are aquatic micro-invertebrates with the ability to survive extreme desiccation, or anhydrobiosis, at any life stage. To gain insight into the molecular mechanisms used by bdelloids during anhydrobiosis, we constructed a cDNA library enriched for genes that are upregulated in Adineta ricciae 24 h after onset of dehydration. Resulting expressed sequence tags (ESTs) were analyse...

Abundance and composition of Rotifera in an abandoned meander lake (Lago Amapá) in Rio Branco, Acre, Amazonia, Brazil. The rotifer community in Lago Amapá (abandoned meander lake of the Rio Acre floodplain) was investigated with respect to seasonal changes. Sampling was performed at three collection stations, generally weekly, during the dry season between May 8, 1997 and October 31, 1997, and ...

Ehoma Lake is among the important breeding sites of the major fishes in the Mid-Cross River, Nigeria. The juveniles of these fishes are solely dependent on zooplankton, which has not been studied previously. I studied monthly the lake's physico-chemical variables and zooplankton composition in three stations (littoral, sub-littoral and pelagic) from March 2005 to August 2006. Sixty-seven zoopla...