An overview of the contribution of studies with cladocerans to environmental stress research

Abstract

Cladocerans are microcrustaceans component of the zooplankton in a wide array of aquatic ecosystems. These organisms, in particular the genus Daphnia, have been widely used model organisms in studies ranging from biomedical sciences to ecology. Here, we present an overview of the contribution of studies with cladocerans to understanding the consequences at different levels of biological organization of stress induced by environmental factors. We discuss how some characteristics of cladocerans (e.g., small body size, short life cycles, cyclic parthenogenesis) make them convenient models for such studies, with a particular comparison with other major zooplanktonic taxa. Then we illustrate the contribution of cladocerans to stress research with examples encompassing stress responses spanning from the molecular to the populational level. Most worth of note are recent studies that presented evidence of beneficial consequences of mild stress caused by natural stressors (cross-tolerance), which may be passed along across generations, favoring individual survival and species persistence in fluctuating environments. This would be particularly relevant for environments prone to frequent natural environmental fluctuations, such as coastal lagoons and other shallow aquatic ecosystems. Based on reviewed studies, a conceptual model is presented summarizing the potential effects of a first stressor on the organism's resistance to a second one. We finish by highlighting some gaps on environmental stress research that could benefit from further studies using cladocerans as model organisms.

Influence of salinity on the life table demography of a rare Cladocera Latonopsis australis

“…Cladocera is a good model organism in field and experimental studies due to their short-generation time (Larsson and Miracle 1997;Forro et al 2008;Suhett et al 2015). They are generally herbivorous but can also feed on bacteria, organic detritus, and dissolved organic matter (Arnold 1971;Boersma and Vijverberg 1996;Abrantes and Gonçalves 2003) and function as prey for larger invertebrates and fishes.…”

How planktonic microcrustaceans respond to environment and affect ecosystem: a functional trait perspective

“…In freshwaters, there is more information available on cladocerans than copepods. Short life cycles and parthenogenetic reproduction make cladocerans convenient models for laboratory experiments (Suhett et al 2015). Copepods, on the other hand, have complex life cycles and obligatory sexual reproduction; thus, laboratory populations are harder to maintain.…”

An overview of Cladoceran studies conducted in mine water impacted lakes

“…Besides the literature reviewed here, there are additional important resources for anyone working with cladocerans and mine pollution: The current role of cladocerans in ecotoxicological research in general has recently been reviewed by Sarma and Nandini (2006) and Suhett et al (2015). In addition, the most important cladoceran species in toxicology research is Daphnia, which was extensively reviewed by Lampert (2011).…”

“…There is a large body of knowledge regarding the effects of harmful substances on cladocerans from in vitro testing (Sarma and Nandini 2006;Suhett et al 2015). In fact, the applicability of cladocerans to mining contamination assessment is further highlighted in Canadian metal mining effluent regulations (Canadian Government 2002), which include Daphnia magna monitoring tests to be conducted on a monthly basis as a part of mine water monitoring programs.…”