Compared with other annelids, echiurans have relatively few setae (bristles). In most species, there are just two, located on the underside of the body just behind the proboscis, and often hooked. In others, such as "Echiurus", there are also further setae near the posterior end of the animal. Unlike other annelids, adult echiurans have no trace of segmentation. Most echiurans are a dull grey or brown but a few species are more brightly coloured, such as the translucent green "Listriolobus pelodes".