Daphnia spp.

PAHs can be bioconcentrated or bioaccumulated by certain aquatic invertebrates low in the food chain that lack the capacity for effective biotransformation (Walker and Livingstone 1992). Mollusks and Daphnia spp. are examples of organisms that readily bioconcentrate PAH. On the other hand, fish and other aquatic vertebrates readily biotransform PAH so, biomagnification does not extend up the food chain as it does in the case of persistent polychlorinated compounds. As noted earlier, P450-based monooxygenases are not well represented in mollusks and many other aquatic invertebrates (see Chapter 4, Section 4.2) so, this observation is not surprising. Oxidation catalyzed by P450 is the principal (perhaps the only) effective mechanism of primary metabolism of PAH. 

Organization for Economic Cooperation and Development (OECD). Daphnia spp.. Acute Immobilization and Reproduction Test. OECD Guideline for Testing Chemicals Organization for Economic Cooperation and Development Geneva, 1984 Vol. 202. 

Environmental Protection Series (EPS). Biological Test Method Acute Lethality Test Using Daphnia spp. Report EPS 1/RM/ll, Environment Canada, 1990 57 pp. 

Other fish species do not respond to predator odors. The threadfin shad, Doro-soma petenense, is strongly attracted to odors of its prey such as brine shrimp [Artemia) or Daphnia spp. but does not respond to those of its predator, the large-mouth bass, M. salmonides, or conspecifics. Both shad and bass swim faster than chemicals travel in water, which may explain this behavior difference (McMahon and Tash, 1979). 

Cooman, K., Gajardo, M., Nieto, J., Bomhardt, C. and Vidal, G. (2003) Tannery wastewater characterization and toxicity effects on Daphnia spp., Environmental Toxicology 18 (1), 45-51. 

Symbol Behavior (algae/ Daphnia spp./ fishes) Corresponding elements Commentary... 

Biological regulation of phytoplankton biomass greatly improved water quality in Lake Washington. The appearance of the aggressive phytoplankton grazer, the microcrustacean Daphnia spp., coincided with an increase in water transparency to as much as 12.9 m by 1976. 

Environment Canada. 1990a. Biological test method Acute lethality using Daphnia spp. Environment Canada, Environmental Protection, Conservation and Protection. Environmental Protection Series Report EC-EPS 1/RM/ll, Ottawa, Canada. 

The OECD Daphnia spp acute immobilisation and reproduction tests. A mainstay in aquatic toxicity testing, Daphnia tests have been used also to evaluate the toxicity of contaminated groundwaters and leachates (Kross and Cherryholmes, 1992). As with any of the aquatic tests, the principal problem with the Daphnia test is the need to extract a suitable aqueous sample. This problem is illustrated by Kross and Cherryholmes (1992), who compared D. magna and Microtox assay results in leachates but found a poor correlation between the two methods. 

J. Borgeras, D.O. Hessen (2002). Species-specific and clone-specific expression of anti-oxidants and pigmentation in Daphnia spp., Hydrobiologia, in press. 

J. Ringelberg (1999). The photobehavior of Daphnia spp. as a model to explain diel vertical migration in zooplankton. Biol. Rev., 74, 397-423. 

Crossland, N.O. and J.M. Hillaby. 1985. Fate and effects of 3,4-dichloroaniline in the laboratory and in outdoor ponds II. Chronic toxicity to Daphnia spp. and other invertebrates. Environ. Toxicol. Chem. 4 489-499. 

The amount of zooplankton is known to decrease under cyanobacterial bloom conditions. Most studies on the effects of cyanobacteria on zooplankton have dealt with Daphnia spp. Fewer studies have been done with crustaceans and rotifers. Out of the invertebrate biotests commonly used, the Anemia salina test seemed attractive [156]. One advantage of A. salina as a test organism is that it is easy to grow from dried eggs available in any aquarium shop. 

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