Daphnia


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Related to Daphnia: Daphnia pulex

Daphnia

 

a genus of freshwater animals of the suborder Cladocera. Daphnia measure 1–3 mm and have a transparent, oval, chitinous shell, whose valves are united on the dorsal side and open in the form of slits on the ventral side. Daphnia are dioecious. Some summer generations are represented only by females, which reproduce parthenogenetically. In the fall, males also appear; fertilization occurs, the females deposit one or two fertilized eggs, which are covered with a thick membrane. These eggs hibernate; in the spring females develop from them. There are a total of 26 species, 14 in the USSR; they are distributed everywhere, except in polar regions. Daphnia live in lakes, ponds, temporary bodies of water, and the backwaters of slow-moving rivers. They feed on bacteria, unicellular algae, protozoans, and the smallest particles of plant detritus. Daphnia serve as food for recently hatched and young fish (they are raised for this purpose in fisheries). Daphnia are intermediate hosts of some worms that in their adult form parasitize various vertebrates, including domestic ducks.

References in periodicals archive ?
2007), when analysing the toxicity of chlorpyrifos and TCP to Daphnia carinata, found that TCP is significantly more toxic to Daphnia spp.
Hurley said adaptation to salt is likely affecting Daphnia at the epigenetic level, a heritable change in gene levels rather than genetic code.
Burnak ve Beklioglu (2000), Mogan Golu'nde Cladocera'dan Daphnia pulex, Ceriodaphnia sp, Bosmina longirostris, Diaphanosoma lacustris, Chydorus sphaericus ve Alona sp.
Blaustem (1998) showed that Notonecta was responsible for structuring the community by size selective predation, resulting in density reduction of larger Daphnia, without affecting the density of the smaller Ceriodaphnia.
NBR 12713: Ecotoxicologia Aquatica--Toxicidade aguda--Metodos de ensaios com Daphnia ssp (Crustacea, Cladocera) (3a ed.
The ultrastructure of the gill epithelium of Daphnia magna acclimated to different salinities was investigated by Kikuchi (1983).
7) Within the last decade, scientists have started to use Daphnia in biomedical research as a surrogate species for genomic responses to environmental stressors.
In this paper it is studied the effect of structure of aliphatic n-alcohols, phenols, sodium salts of aalkoxycarbonylsulfuric acids and their mixtures on toxicity towards Daphnia Magna [14].
Ademas del alimento, la temperatura afecta la dinamica poblacional de los cladoceros al establecer rangos estrechos para su optimo crecimiento, como Daphnia magna a 18-20[grados]C, Daphnia longispina, Daphnia pulex y M.
The idea to send Daphnia to space has been thought up by students from Rhondda Cynon Taff and their project was selected at the end of the Mission Discovery programme at King's College London by a team of scientists led by NASA Space Shuttle Commander Ken Ham.