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Daphnia lumholtzi is typically found in the warm, shallow regions [6] of bodies of water with larger surface areas. [7] While most species of Daphnia see high mortality at temperatures greater than 25 °C, [8] D. lumholtzi individuals can survive and reproduce at temperatures up to 30 °C, [8] [9] [10] with a thermal optimum occurring at 29 °C. [9]
Daphnia is a genus of small planktonic crustaceans, 0.2–6.0 mm ... (e.g. to study the effect of temperature on the heart rate of these ectothermic organisms).
Other Daphnia species than D. magna may occasionally be used, but labs mostly use D. magna as standard. Test No. 211 is a 21-day chronic toxicity test, at the end of which, the total number of living offspring produced per parent animal alive at the end of the test is assessed, to determine the lowest observed effect concentration of the test ...
[5] [8] Although the process through which the genotypic interactions occur is unclear, environmental factors, such as temperature, play a large role in the castration of Daphnia. Studies have shown that female Daphnia are sterilized at warmer temperatures (20–25 °C (68–77 °F)), but still have the ability to reproduce at lower ...
For example, a study used Daphnia and a fish that was too small to prey on them (Lebistus reticulatus), found that with the introduction of the fish to the system the Daphnia remained below the thermocline, where the fish was not present. This demonstrates the effects of kairomones on Daphnia DVM. [24]
The effects of temperature on enzyme activity. Top - increasing temperature increases the rate of reaction (Q 10 coefficient). Middle - the fraction of folded and functional enzyme decreases above its denaturation temperature. Bottom - consequently, an enzyme's optimal rate of reaction is at an intermediate temperature.
Daphnia cephalata King, 1853; Daphnia chevreuxi Richard, 1896; Daphnia chilensis (Hann, 1986) Daphnia coronata Sars, 1916; Daphnia dadayana Paggi, 1999; Daphnia deserti Gauthier, 1937; Daphnia dolichocephala Sars, 1895; Daphnia ephemeralis (Schwartz & Hebert, 1985) Daphnia exilis Herrick, 1895; Daphnia fusca Gurney, 1907; Daphnia gelida (Brady ...
Daphnia pulicaria have a translucent carapace and two prominent second antennae, which they use to move. [11] The carapace, composed primarily of chitin, helps protect the feeding apparatus, and it is periodically shed during an individual's life. [11] Daphnia have a compound eye, and they are known to have an optomotor response. [12]