Here are some black worms Chloé found in a mountain pond sample! She put them under polarized light to make them glow as if they were raving. They’re mainly found in North America and Europe in freshwater ponds, lakes and marshes especially in shallow water in sediments or decaying leaves. They’re known to be decomposers as they feed on organic matter but they also nom on microbes!
Black worms belong to the annelid worm group and more precisely the oligochaete worms, just as earthworms! Oligochaete worms are segmented animals, meaning that their body is made of small repetitive units and all of them possess a pair of primitive kidneys and components of circulatory and nervous system. Primitive kidneys are essential to remove wastes from blood and the body cavity. The different segments also bear a pair of bristles, called setae, which are use to anchor the worm when moving around. But to move around so easily by crawling on surfaces also means muscles are needed! Circular and longitudinal muscles are here to help these worms to lengthen and contract all of their segments to be able to stretch forward and eat all of the food!