by Duane Craig
|Water fleas help scientists test the effect of contamination|
It’s often said that if you want to know how contaminated an area is then look to the smallest of its members. Frogs, for example, are an important bellwether in the ecosystem and when they are stressed from contamination then the system is on the verge of collapse.
Well, now the frogs are joined by an even smaller being called a water flea. Scientists recently concluded mapping the insect’s genome and discovered that it increases a protective molecule that reduces its reproductive success when it is exposed to cadmium. Cadmium is a common contaminant.
The fleas have many shared genes with humans so researchers believe they can assess how contamination will potentially affect humans by studying the effects it has on the fleas.
Water fleas are crustaceans, are prevalent across North America, South America, Europe and Australia, and they typically live in small ponds. This particular species, Daphnia pulex, doesn’t have any defenses against invertebrate predators and that allows it to have a high reproductive rate.