There is a gap in our understanding of the relative and interactive effects of different parasite species on the same host population. Here we examine the effects of the acanthocephalan Acanthocephalus galaxii, an unidentified cyclophyllidean cestode, and the trematodes Coitocaecum parvum and Microphallus sp. on several fitness components of the amphipod Paracalliope fluviatilis, using a combin...

Light scattering by zooplankton was investigated as a major factor undermining transparency camouflage in these pelagic animals. Zooplankton of differing transparencies--including the hyperiid amphipod Anchylomera blossevillei, an unknown gammarid amphipod species, the brine shrimp Artemia salina, the euphausiid shrimp Euphausia diomedeae, the isopod Gnathia sp., the copepods Pontella karachien...

Key-words: whole-sediment toxicity tests, sensitivity comparison, Hyalella azteca, Heterocypris incongruens, ostracod microbiotest The review first details the development of the test procedures with Hyalella azteca which historically emerged as one of the recommended test species for whole-sediment assays and its gradual standardization and endorsement by national and international organizatio...

Nearshore marine benthic algal communities along the western Antarctic Peninsula harbour extremely high densities of amphipods that probably play important roles in nutrient and energy flow. This study extends our evaluation of the importance of amphipods in the nearshore Antarctic Peninsular benthic communities and focuses on sponge associations. We found a mean density of 542 amphipods per li...

Larval helminths that share the same intermediate host may or may not also share the same de®nitive hosts. If one or more of these helminth species can manipulate the phenotype of the intermediate host, there can be great advantages or severe costs for other helminths resulting from co-occurring with a manipulator, depending on whether they have the same de®nitive host or not. Among 2372 specim...

Habitat connectivity crucially influences dispersal of organisms. It is especially seen as an important driver of the spatial structuring of biological communities in ecosystems that have intrinsic and general connectivity patterns, such as the universal dendritic structure of fluvial networks. These networks not only define dispersal of native species, but also represent corridors of biologica...

In the last decades, zebra mussels (Dreissena polymorpha) have invaded many freshwater systems with severe consequences for entire communities. Most benthic macroinvertebrates, especially amphipods and chironomids, increase in abundance in the presence of zebra mussels. Increased structural complexity and an unknown biotic factor lead to this effect. Dreissena-associated factors that might infl...

1. Accumulation of organic material by the zebra mussel Dreissena polymorpha is assumed to be the source of a biodeposition-based food web. However, only little is known about the importance of the biodeposited material as a food source and its contribution to increased abundances of macroinvertebrates in the presence of D. polymorpha. 2. Feeding, assimilation and growth of the amphipods Gammar...

Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N....