nephrostome

{{More citations needed|date=February 2023}}

File:Annelid redone w white background.svg worm showing the metanephridia and both nephrostomes in one of the animal's segments]]

The nephrostome{{Cite web |title=Archinephros {{!}} anatomy {{!}} Britannica |url=https://www.britannica.com/science/archinephros |access-date=2023-02-07 |website=www.britannica.com |language=en}} is the funnel-like component of a metanephridium. It is always oriented towards the coelom. The nephrostome is covered from the inside with cilia, which push the water, metabolic wastes, unnecessary hormones and other substances into the metanephridium.