Nematodes from extreme freshwater habitats.

Abstract

This paper discusses the ecology and biogeography of nematodes from freshwater environments, which are extreme in terms of temperature, chemical composition, variability or isolation. The composition of nematode faunas from freshwater pools in bromeliads or tree hollows, hot or mineral springs, pools and bogs in polar regions, seasonal lakes or pools, fresh groundwaters and caves are described and compared. The nematode faunas from these extreme habitats are also compared with those from more typical freshwater environments. Nematodes with evolutionary affinities to freshwaters but found in estuarine sediments are discussed. Conversely, nematodes from freshwaters with evolutionary affinities to otherwise marine taxa are also considered. Common themes in the adaptations of all these nematodes to such unusual environments are synthesized.

Spatiotemporal Distribution of Free-Living Nematodes in Glacial-Fed Stream Reaches (Hohe Tauern, Eastern Alps, Austria)

“…470-480 Womersley et al, 1998), and low food resources (Perry and Wright, 1998). Given these abilities, nematode presence in extreme freshwater habitats (reviewed in Hodda et al, 2006) does not seem surprising. But in spite of these factors, scarce data exist on nematode distribution in glacial streams, where they could be assumed to be present and, hence, to be of importance.…”

Cosmopolitism and endemism in free-living nematodes

“…The lac Geneva or Léman, the largest Alpine lake, is not so old, but still hosts at a depth of 60 m some endemic Desmoscolecidae (only 0.2 mm long), nematodes common in sea but very rare in fresh water. Extreme environments are isolated by their differing environmental setting and thus often host unique species assemblages (Hodda et al 2006). For Antarctica, being very different from all other continents, 94% of all nematodes are considered to be endemic for this continent (Andrássy 1998(Andrássy , 2008.…”

Global diversity of nematodes (Nematoda) in freshwater

“…Studies of fluctuating environments such as vernal pools and ephemeral water bodies (Hodda et al, 2006) provide excellent examples of the resilience of nematode communities. Their ability to withstand harsh environmental fluctuations allows them to cross barriers that may significantly limit the distribution of larger organisms.…”