By Susan Milius
A bird parasite here, a snail parasite there, and pretty soon you’re talking about real biomass.
Parasites, including plenty that sabotage snail reproduction, add up to an amount of flesh that’s “surprisingly substantial,” says Armand Kuris of the University of California, Santa Barbara.
Although ecologists recognize that parasites can affect ecosystems, many food web analyses assume that parasites don’t account for much of the actual mass of living tissue, he says.