of Nephridium
Source: Webster's dictionaryA pair of former nephridia in the head were converted secondarily into the salivary glands, while another pair in the final segment of male specimens now serve as glands that apparently play a role in reproduction. Source: Internet
Historically, the salivary glands probably evolved from the waste-elimination organs known as nephridia, which are found homologously in the other body segments. Source: Internet
Excretory organs In almost every segment is a pair of excretory organs called nephridia, which are derived from coelom tissue. Source: Internet
These marine worms are nutritionally dependent on their symbiotic chemoautotrophic bacteria lacking any digestive or excretory system (no gut, mouth, or nephridia ). Source: Internet
Nephrocytes absorb toxins or convert them into a form suitable for elimination by the nephridia. Source: Internet