Interclonal Variation in the Performance of Daphnia Magna Straus in Chronic Bio Assays

Abstract

As an ecotoxicological test organism, Daphnia magna Straus has a long history and is now used extensively. Despite this, considerable variation in interlaboratory bioassays using the same reference toxicant has been reported. Using a standard quantitative genetics approach, the relative tolerance of different genotypes of Daphnia magna to two toxicants (sodium bromide and 3,4‐dichloroaniline) was assessed. As expected, the environmental component of variability dominated the chronic response with a significant component of interaction. Differences between genotypes, although significant, were not large. It was concluded that genotype‐environment interactions played a key role in determining chronic responses of Daphnia magna to both compounds. Some suggestions are given to improve the level of repeatability in Daphnia magna bioassays.

Tolerance of genetically characterized Folsomia candida strains to phenmedipham exposure

“…Exposure tests with F. candida could be chronically biased due to genetically fixed tolerance differences, as e.g. found in Daphnia magna (Soares et al 1992, Münziger & Monicelli 1991. Comparisons of variation in cadmium tolerance between clonal lineages of this species showed differences of two orders of magnitude (Baird et al 1991).…”

“…In contrast to this, considerable levels of genetic differentiation have recently been found between natural F. candida populations as well as between laboratory clones (Chenon et al 2000, Frati et al 2004, Tully et al 2006. These genetic differences between test strains could affect sensitivity towards toxic stress, as has been shown in daphnids (Baird et al 1990, Baird et al 1991, Soares et al 1992 or gastropods (Jacobsen & Forbes 1997, Jensen & Forbes 2001.…”

Salinity effects on survival and life history of two freshwater cladocerans (Daphnia magna and Daphnia longispina)

“…Monoclonal cultures of Daphnia magna (clone A, sensu Baird et al 1989a) and Daphnia longispina (clone EM7, sensu Antunes et al 2003) have been reared in our laboratory for several generations using widespread procedures for D. magna (see Baird et al 1989b, Soares et al 1992, ASTM 1997. Daphnids were cultured in American Society for Testing and Materials hard water medium (ASTM 1980), to which an organic additive (Ascophyllum nodosum extract, Baird et al 1989b) was added.…”

Alternative Biotest on Artemia franciscana

“…(Soares, et al, 1992). For example, George-Ares et al (2003) On the other hand, the Artemia alternative tests offer many advantages to favour them as convenient for the standardized testing in ecotoxicology: high adaptability to variety of testing conditions, high fecundity, bisexual versus parthenogenetic reproduction strategies, small body size, varied nutrient resources, high hatchability, simple availability, and low cost of the tests.…”