Eunicidae is a family of marine polychaetes (bristle worms). The family comprises marine annelids distributed in diverse benthic habitats across Oceania, Europe, South America, North America, Asia and Africa. The Eunicid anatomy typically consists of a pair of appendages near the mouth (mandibles) and complex sets of muscular structures on the head (maxillae) in an eversible pharynx. One of the most conspicuous of the eunicids is the giant, dark-purple, iridescent "Bobbit worm" (Eunice aphroditois), a bristle worm found at low tide under boulders on southern Australian shores. Its robust, muscular body can be as long as 2 m. Eunicidae jaws are known from as far back as Ordovician sediments. Cultural tradition surrounds Palola worm (Palola viridis) reproductive cycles in the South Pacific Islands. Eunicidae are economically valuable as bait in both recreational and commercial fishing. Commercial bait-farming of Eunicidae can have adverse ecological impacts. Bait-farming can deplete worm and associated fauna population numbers, damage local intertidal environments and introduce alien species to local aquatic ecosystems. In 2020, Zanol et al. stated, "Species traditionally considered to belong to Eunice are now, also, distributed in two other genera Leodice and Nicidion recently resurrected to reconcile Eunicidae taxonomy with its phylogenetic hypothesis." History of knowledge In 1992, Kristian Fauchald detailed a conclusive history of research and classification of the Eunicidae family. Primary studies undertaken in 1767 on coral reefs in Norway, initially classified Eunicid species under the Nereis family. In 1817, Georges Cuvier created a new genus, Eunice, to classify these and other original taxa. Throughout the 1800s (1832-1878) worm species were added to this genera by Jean Victor Audouin and Henri Milne-Edwards, Kinberg, Edwardsia de Quatrefages, Malmgren, Ehlers and Grube. Following the Challenger and Albatross expeditions, research was expanded by McIntosh and Chamberlain. In 1921 and 1922, Treadwell added new species from coral reefs in the Caribbean Sea and the Pacific Ocean. Species were reviewed and their classifications were refined by Fauvel, Augener and Hartman throughout the early 1900s. In 1944, Hartman codified a system of separate classification for the family, informally grouping North American species using the original suggestions of Ehlers. Hartman's system was expanded and specified by Fauchald in 1970 and later again by Miura in 1986. Taxonomy Thirty-three genera have been described in the Eunicidae family. Only eight are currently considered valid: Aciculomarphysa (Hartmann-Schroeder, 1998 in Hartmann-Schroder & Zibrowius 1998) Eunice (Cuvier, 1817) Euniphysa (Wesenberg-Lund, 1949) Fauchaldius (Carrera-Parra &