Nereidae are commonly found in all water depths. Most Nereidae are morphologically similar, but they dwell in different habitats. Some species live on rocky shores, creep under stones or burrow in sandy mud.

Prostomium

   2 pair of eyes present, most species have 2 antennae, but one genus has 1 antenna only. Palps are biarticulated. 2 or 4 pairs of tentacular cirri.

   Eversible pharynx equipped with a pair of jaws, often with accessory denticles or papillae.

Proboscis

The proboscis is divided into 2 rings. They are basal and oral rings. The mouth opening at the oral ring equips with 2 toothed jaws.

Proboscis (Dorsal)     

Proboscis (Ventral)

Parapodia and Setae

   Parapodia are mostly biramous. The first two pairs, however, are uniramous. Usually with complex flattened lobes and cirri.

   Setae composite or simple, spinigerous or falcigerous.

Parapodia biramous

Compound and

  spinigerous setae