Covered by water drift6/22/2023 They have also been collected from high-altitude lakes (up to 5,600 m above sea level) (Andrássy, 1978 Tsalolikhin, 2014), from deep-sea regions (down to 11,000 m below sea level) (Bik et al., 2010 Leduc & Rowden, 2018) and from caves and groundwater (Muschiol et al., 2015). They can be found in permanent lotic and lentic surface waters, such as lakes and streams, and in the seabed. Nematodes are the most abundant metazoans in the biosphere and colonize nearly all aquatic and semi-aquatic habitats worldwide. Their immigration is continuous, and supported by their rapid, parthenogenetic reproduction, nematodes are effective pioneers with the ability to (re)colonize new or disturbed habitats or rebalance already existing communities. The diversity of possible dispersal modes is high and offers a reasonably chance for gravid females or groups of nematodes to be transferred even to remote environments. Overland dispersal vectors include wind and birds whereas rafting enables an aggregated distribution because food is available, and reproduction is possible onboard the rafts. In fact, the transport of nematodes over thousands of kilometers via ship water tanks and by hitchhiking on sea turtles has been documented. Active dispersal is effective over short distances, but with increasing water-flow velocity, passive dispersal modes, which enable long-range transfer, become important. These modes are limited by morphology and habitat structure, ecological factors and especially by hydrodynamics. In this review, we examine the underlying dispersal modes, considering their active movement in substrates and water, their drift by water and wind, rafting, zoochory as well as human-mediated vectors. Despite their small size, restricted locomotion and lack of pelagic larvae, they can reach even isolated habitats within a short time. Nematodes colonize almost all aquatic habitats worldwide.
0 Comments
Leave a Reply. |