C. elegans nematode worm. Light microscopy footage of a specimen of the nematode roundworm Caenorhabditis elegans. Nematodes are small worms found in a range of environments worldwide. C. elegans is a transparent, soil-dwelling nematode, found in temperate climates. It feeds on bacteria, and reaches lengths of about 1 millimetre. C. elegans is used extensively in biological research. In this footage, the head end moves forward, probing its environment, disappearing from view towards bottom centre. The tapered tail end appears midway through the clip. The internal body organs, mostly reproductive structures, are visible.