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Latest Daphnia Stories

Is It Possible For A Tropical Water Flea To Invade European Lakes?
2013-03-19 11:11:48

Pensoft Publishers Experiments predict that populations of native European species may be substantially suppressed by the invader Daphnia is a genus of small, planktonic crustaceans, commonly called 'water fleas' because of their jumpy swimming style and their size (between 0.2 and 5 mm). They live in various aquatic environments, ranging from acidic swamps to freshwater lakes, ponds, streams and rivers. Species of the genus Daphnia play a key role in freshwater food webs: they consume...

2012-05-23 17:08:34

Environmental change is the selective force that preserves adaptive traits in organisms and is a primary driver of evolution. However, it is less well known that evolutionary change in organisms also trigger fundamental changes in the environment. Yale University researchers found a prime example of this evolutionary feedback loop in a few lakes in Connecticut, where dams built 300 years ago in Colonial times trapped a fish called the alewife. In a study published May 23 in the journal...

2012-04-02 11:08:30

Less resistance can sometimes be better than more--at least in a freshwater lake When battling a deadly parasite epidemic, less resistance can sometimes be better than more, a new study suggests. A freshwater zooplankton species known as Daphnia dentifera endures periodic epidemics of a virulent yeast parasite that can infect more than 60 percent of the Daphnia population. During these epidemics, the Daphnia population evolves quickly, balancing infection resistance and reproduction....

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2012-03-30 13:23:23

When it comes to battling a deadly parasite epidemic, it may be better not to fight it.  A new study of freshwater zooplankton suggests less is more when it comes to evolving against a parasitic epidemic. The zooplankton, known as Daphnia dentifera, has been found to endure a yeast parasite infection known to affect more than 60% of its population. What scientists found interesting is how quickly the Daphnia population evolves, balancing infection, resistance, and reproduction....

2012-03-29 23:15:36

When battling an epidemic of a deadly parasite, less resistance can sometimes be better than more, a new study suggests. A freshwater zooplankton species known as Daphnia dentifera endures periodic epidemics of a virulent yeast parasite that can infect more than 60 percent of the Daphnia population. During these epidemics, the Daphnia population evolves quickly, balancing infection resistance and reproduction. A new study led by Georgia Institute of Technology researchers reveals that...

Loss Of "Lake Lawnmowers" Leads To Algae Blooms
2011-09-29 04:03:29

Unprecedented algae growth in some lakes could be linked to the decline of water calcium levels and the subsequent loss of an important algae-grazing organism that helps keep blooms at bay. Daphnia–also known as water fleas–act like microscopic lawnmowers in lakes, feeding on algae and keeping it in check. However, without sufficient calcium, these water fleas cannot reproduce. “When water calcium levels get low and Daphnia populations decrease in any lake, algal...

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2011-06-24 11:03:54

Biologists worldwide subscribe to the healthy herds hypothesis, the idea that predators can keep packs of prey healthy by removing the weak and the sick. This reduces the chance disease will wipe out the whole herd, but could it be that predators can also make prey populations more susceptible to other predators or even parasites? Biologists at the Georgia Institute of Technology have discovered at least one animal whose defenses against a predator make it a good target for one opportunistic...

2011-03-25 11:18:42

Researchers from Osaka University and the National Institute for Basic Biology, Japan, have found a highly significant connection between the molecular mechanisms underlying genetic and environmental sex determination. The scientists report in the open-access journal PLoS Genetics the identification of a gene responsible for the production of males during environmental sex determination in the crustacean Daphnia. Ways in which an individual organism's sex is determined are diverse among...

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2011-03-23 09:15:52

There are many different kinds of crustaceans, ranging from the shellfish Swedish people eat at traditional crayfish parties every August to tiny relatives found in their millions in both freshwater and saltwater. One of the latter, Daphnia pulex, is the first crustacean to have its genome sequenced. A researcher from the University of Gothenburg has made a surprising discovery. The sequencing has been done in an international research network known as the Daphnia Genomics Consortium. The...

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2011-02-03 14:05:00

Scientists have mapped the genome of the waterflea, revealing the most gene-packed animal characterized to date. The information deciphered of the tiny crustacean could help researchers develop and conduct real-time monitoring systems of the effects of environmental remediation efforts. The waterflea, or the Daphnia pulex, is considered a keystone species in freshwater ecosystems and is roughly the size of an equal sign on a keyboard.  The Daphnia pulex is the first crustacean to have...


Word of the Day
grass-comber
  • A landsman who is making his first voyage at sea; a novice who enters naval service from rural life.
According to the OED, a grass-comber is also 'a sailor's term for one who has been a farm-labourer.'