The over 1,000 species of ribbon worms (Nemertea) are mostly found in marine environments (like the Hubrechtia found in a mud flat, in the photo). These worms have both a mouth and an anus (unlike flatworms, which use the same opening for both ingesting and removing their food). Some species are centimeters long, like the ones that Smithsonian scientists searched for in Florida, while others, like the monstrous Parborlasia corrugatus, grows up to 2 meters in length and can be found littering the ocean bottom of Antarctic and sub-Antarctic regions.