Guppies at the Top of the Food Chain
Posted by Shari Horowitz in Tropical Fish Hobbyist Blog on December 13, 2011 at 9:34 am
SAN FRANCISCO — Lions and tigers and bears and … guppies?
Don’t let its tiny size, delicate tail or fondness for aquarium life fool you; a new chemical analysis places the guppy high up on the food chain, above even a shark, according to Greg Michalski, an assistant professor at Purdue University. The little fish becomes the “great white guppy,” as he calls it.
The analysis relies on atoms of nitrogen with different weights, called nitrogen isotopes. The heavier version, nitrogen-15, accumulates farther up the food chain. So, a plant would have the lowest levels of heavy nitrogen, and a top predator, say a shark or a tiger, would have the highest. This is similar to what happens with the toxic element mercury, but nitrogen is necessary for life.
Source: http://www.msnbc.msn.com/id/45643428/ns/technology_and_science-science/#.TueKfbJBVp4
Photograph courtesy of TFH Archives
