Polychaetes are dominant benthic fauna in the marine environment. These marine worms are multi-segmented annelids with parapodia and beautifully patterned and coloured with irridescent or bright primary colours. Around 10,000 species have been described worldwide so far. Most polychaetes are less than 10 cm long and between 2 mm and 10 mm wide.

Polychaetes occur in most habitats ranging from estuaries and inshore waters to the open sea and and abyssal depths. Many species are found along intertidal areas, especially on sandy or muddy beaches and in coastal lagoons. The majority of these ancient group of worms are benthic while 50 planktonic species are distributed throughout the world's region.