Water Quality Assessment Using Daphnia: A Brief Review

Due to the need to discover methods that can measure the toxicity level of fresh and marine water quality, this study aimed to present a systematic review of the literature, indicating the culture conditions and toxicological tests used for different Daphnia species in the evaluation of water quality. Thus, the applied methodology was a systematic review that identified studies that addressed the application of Daphnia in the assessment of water quality. The results obtained from this research consisted of a compilation of articles, which presented the parameters most analyzed in Daphnia species, such as mobility and mortality, which can change when exposed to different chemical substances.

Predator-induced allometric changes in the tail spine length of Daphnia: a distinct resource allocation strategy

Understanding resource allocation strategies underlying inducible defense is a challenging scientific issue, because of the difficulty in measuring resource allocations of defensive traits. We examined allometric changes to evaluate resource allocation strategies on the tail spine of Daphnia within and between species and further explore the allometric changes at different developmental stages and their relationship with growth and reproduction. We found that four Daphnia species (Daphnia magna, Daphnia sinensis, Daphnia galeata and Daphnia mitsukuri) can perform significant inducible defensive responses when exposed to fish kairomone. Different from the other Daphnia species, D. mitsukuri significantly enhanced the allometric slope of its tail spine when exposed to fish kairomone. We also found that allometric changes among different D. mitsukuri clones are significant in adult individuals. Furthermore, the allometric changes show a significant negative interaction with individual growth, indicating that a trade-off may exist between the resource allocations of tail spine elongation and growth. This study highlights the species-specific allometric changes in tail spine elongation and provides an explanation for this from resource allocations.