Brazilian researcher Marcela Uliano da Silva shows samples of the golden mussel at the Carlos Chagas Filho Biophysics Institute in Rio de Janeiro, Brazil, in 2015. The golden mussel, which commonly grows to no more than an inch in length, is a hardy breeder, reproducing nine months a year by releasing clouds of microscopic larvae that float with the current to new territories. They attach to hard surfaces like river bedrock, stones, man-made structures and even each other, forming large reef-like structures. PHOTO BY LEO CORREA — AP PHOTO