uruguayensis in the littoral and limnetic
zones and in the wann-wet and cool-dry seasons were compared by the non-parametric Mann-Whitney test.
To examine the relationship between temperature and cladoceran community patterns, four sample sites, two on each arm, were established in the limnetic
zone of Newton Lake (Fig.
More recent divergences include postglacial evolution of benthic and limnetic
species pairs (McPhail 1994; Taylor et al.
Valdivia River, this study), and over 20km upstream in low salinity (limnetic
Instead, it could have implied two recolonization events from the same race, as has been hypothesized for explaining the origins of sympatric pairs of benthic and limnetic
sticklebacks (McPhail 1994).
In Paxton Lake, benthic males tend to build nests in areas of the freshwater alga, Chara sp., while limnetic
males tend to nest in the open (McPhail 1994).
These authors hypothesize that shallow aquatic ecosystems (up to 2 m deep), where the limnetic
region is reduced or nonexistent, may have most or all lake area covered by macrophytes.
Sampling design: Three zooplankton samples were taken in limnetic
area (without vegetation) with a trap tube sampler similar to that used by Paggi et al.
Distinguishing which of the two sets of assumptions, Olsen's or Andersen's, is correct, or indeed whether either set is satisfactory, may be an important unsolved issue in grazer ecology, as it is likely that algal P:C ratios in many limnetic
systems will be lower than P:C values for most grazer species (Elser and Hassett 1994).
Genetic parameters were estimated in the "limnetic
" species of threespine stickleback from Enos Lake (Gasterosteus sp.), Vancouver Island (McPhail 1984; Schluter and McPhail 1992).
The spatial complexity generated by the aquatic plants, and the consequent increase in microhabitat availability, is a major contributing factor for its biodiversity (Nogueira et al., 2003; McAbendroth et al., 2005; Thomaz et al., 2008; Thomaz and Cunha, 2010; Ferreiro et al., 2011), especially when compared to the relatively homogeneous limnetic
zones (e.g.: Maia-Barbosa et al., 2008, found increased richness in littoral vegetated habitats compared to the limnetic
Finally, the results support the notion that temporal variation, even in this small tropical lake, located in a region of low seasonal weather variation, enhances the global phytoplankton diversity of the lake, and explains in part, the coexistence of much larger number of species in a rather uniform environment such as the limnetic
habitat of a small lake (Reynolds 2006).