Competition between " D . lumholtzi " is increased in habitats that favor the high light intensity of shallow waters . " D . lumholtzi " showed greater survivorship than other " Daphnia " species ( specifically " D . pulex " ), which made them a stronger competitor for light reception and resources in bodies of water receiving high light intensity.
32.
This is due to the fact that the mixed feeding frenzies that form during cannibalism and intraguild predation ( IGP ) are likely to promote persistence of the parasite in G . " duebeni celticus ", even when G . " pulex " invades . Thus, the introduction of the pleipshora parasite mediates interspecies predation by decreasing the fitness of G . " celticus ".
33.
One of the most astonishing features of the " D . pulex " genome is its compactness : despite being around 200 Mb in size ( around 16-fold smaller than the human genome which is 3, 200 Mb in size ); its 12 chromosomes contain a minimum set of 30, 907 predicted protein-coding genes, more than the 20, 000 25, 000 contained in the human counterpart.
34.
Combining information on the biology of " Pulex irritans " with modern studies of plague epidemiology, particularly in India, where the " R . rattus " is a native species and conditions are nearly ideal for plague to be spread, Twigg concludes that it would have been nearly impossible for " Yersinia pestis " to have been the causative agent of the plague, let alone its explosive spread across Europe.
35.
They are often associated with a related genus in the order Cladocera : " Moina ", which is in the Moinidae family instead of Daphniidae and is much smaller than " D . pulex " ( approximately half the maximum length ) . " Daphnia " eggs for sale are generally enclosed in " ephippia " ( a thick shell, consisting of two chitinous plates, that encloses and protects the winter eggs of a cladoceran ).
