Brief Summary

Polychaetes are a class of segmented marine worms from the phylum Annelida ("little ring"). Polychaetes live in a wide range of environments and have both free-living and sedentary representatives. Perinereis spp. are benthic free-living organisms which are typically scavengers. One of the most fascinating features of these organisms is their muscularised, eversible pharynx which houses a set of spectacular-looking, grasping jaws. 
 
The family Nereididae was first described as Nereidae by Johnston in 1845. This taxon as well as other polychaete families have been considerably corrected in order to join identically described organisms under single, universal names (Beesley et al., 2000). This movement also incorporated the use of jaws and parapodia in correct identification of the species.

Nereids, commonly called ragworms, can be categorised by their sensory prostomial palps, eversible and muscular pharynx bearing one pair of jaws, four tentacular cirri, typically biramous parapodia and compound falcigers and/or spinigers. They usually have accessory papillae or denticles (paragnaths) in a regular pattern on their pharynx. They are given the name ragworms because of the quick, undulating movements they make with their bodies when disturbed.

Nereids can be found worldwide however they prefer sub-tropical to temperate climatic conditions. A rocky intertidal shore at Redcliffe, QLD, 42km from the city of Brisbane provides a perfect habitat in which to observe and analyse this taxa. A brief study conducted from August to October 2011 supported scientific research as to the positioning of the organism along the intertidal shore in relation to it's maturity (for more information see 'Local Distribution and Habitats'). Another more detailed study conducted at the same time recorded and described the physical process of asexual regeneration of the anterior of the organism's body (for more information see 'Cell Biology').