Nereidids are long and slender worms of medium size found among algae, gravel and shells on hard substrates, or digging into soft substrates. They are characterised, among other features, by well-developed parapodia, and an eversible pharynx with two prominent black jaws and small sclerotised teeth on the surface of the pharynx. During reproduction, many species leave the sea-bed and swarm towards the surface.
Nereidids are long and slender worms found among algae, gravel and shells on hard substrates, or digging into soft substrates. They are characterised by an eversible pharynx with two prominent black jaws and teeth, called paragnaths, distributed in specific patterns on the pharynx. Pointing forward on the head are two large palps and between them a pair of cirriform antennae. At the back of the head there are four pairs of long tentacular cirri. Four black eyes are placed on the head. Well-developed parapodia divided in an upper and a lower part, are easily observed on each segment along the body. Most species modify the body, defined as epitoky, during reproduction, developing enlarged parapodia and swimming chaetae. During reproduction, the species leave the seabed and swarm towards the surface.
Bakken T. Nereididae Blainville, 1818. www.artsdatabanken.no/Pages/313954. Downloaded <year-month-day>.