Family NEREIDIDAE

Perinereis vallata

© Copyright Robin Wilson, Museum Victoria

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Introduction

Nereidids are common, widespread benthic polychaetes that have been extensively studied. They are distinguished by having an eversible pharynx with one pair of jaws and, usually, accessory papillae or denticles in a regular pattern. The range of habitats occupied by nereidids is probably as great as for any other polychaete family — not only do they occur from shallow marine and estuarine habitats to the deep sea, but members of the subfamily Namanereinae can also be found in freshwaters including specialised habitats such as water-filled tree hollows in tropical forests. In most of these habitats nereidids are extremely common. They range in size from a few mm to several cms in length. Within Australia, Australonereis, Olganereis and Simplisetia (formerly Ceratonereis sensu lato) are the principal estuarine genera. In fully marine environments, species of Ceratonereis sensu stricto, Neanthes and Nereis occur on soft sediments, while Perinereis, Platynereis and Pseudonereis are more common on shallow rocky reefs and similar hard substrates.

Modes of feeding are similarly diverse among nereidids: carnivores, herbivores, surface detritus feeders, omnivores and even suspension feeders (using a mucus net) are known. Feeding behaviour can vary even within and between populations of a single species.

Figures of 21 genera and 86 species were given by Beesley et al. (2000: App. 1) for representation of the family in Australian waters, and 43 genera and 535 species worldwide. Presently about 91 species from 22 genera are known from Australia.

See Wilson (2000) for detailed treatment of the family.

Database Notes

proof read against Day & Hutchings 1979 by RW; no subsequent records added

Diagnosis

General features. Body shape vermiform; segments numerous (more than about 15); regionation absent. Pygidium simple ring or cone. Pygidial appendages present; one pair of cirri.
Head & head structures. Head discrete and compact, dorsal to mouth. Prostomium bluntly conical to trapezoidal (narrow end anteriorly) (sometimes called an inverted t-shape). Eyes present (rarely absent); two pairs; situated on prostomium; compound with lenses. Prostomial antennae present (rarely absent); paired arising anterolaterally; smooth. Palps paired; bi-articulated (robust basal part); ventrolateral. Nuchal organs indistinct paired dorsolateral patches. Peristomial ring absent (rather, an enlarged fused annulus present behind head).
Pharynx & pharyngeal apparatus. Foregut a muscular axial pharynx; with one pair of lateral jaws; fang-like (often serrated); without teeth (rarely), or with teeth (=paragnaths) present in distinct areas; surface smooth, or with soft papillae; papillae in distinct areas; distal ring of papillae absent.
Body segments & parapodia. First segment with tentacular cirri. Tentacular cirri 3–4 pair(s); arise on a single segment (which is fused to peristomium); internal aciculae absent. First chaetiger with neurochaetae only, or with both notochaetae and neurochaetae. Parapodia uniramous throughout (rarely), or biramous with prominent parapodial lobes (up to five lobes per parapodium); notopodial lobes represented by at least one chaetal lobe, or absent; neuropodial lobes represented by at least one chaetal lobe. Dorsal cirri more-or-less cirriform, or flattened and foliaceous (rarely). Ventral cirri present, cirriform or tapering. Branchiae absent, or present (rarely); arise from parapodia; occur on at least some chaetigerous segments; digitiform (resemble cirri; one or more per parapodium).
Chaetae. Notochaetae absent (rarely), or present. Aciculae present; in both dorsal and ventral positions (=noto- and neuroaciculae). Capillary chaetae absent. Spines absent. Hooks absent. Compound chaetae present; appendage distally tapering to slender tips (=spinigerous), or distally curved (=falcate); appendage not canaliculated; appendage without hoods or guards; joint more-or-less symmetrical (=homogomph; includes also hemigomph and sesquigomph), or distinctly asymmetrical (=heterogomph); joint effected by ligament(s) (double); shaft tapering slightly or evenly thick from emergence to joint; shaft with camerated core. Compound falcigers present in most or all chaetigers.
Tube & burrow. Tube absent or unconsolidated, or membraneous. Burrow traces absent, or comprises interconnected galleries.

The above description was generated from: 'C.J. Glasby & K. Fauchald (2002 onwards). POLiKEY. An information system for polychaete families and higher taxa: Version 1: September 2002.'
(See ABRS website: Online Resources: Polikey, for Version 2, released June 2003)

General References

Alves, P.R., Halanych, K.M., Silva, E.P. & Santos, C.S.G. 2023. Nereididae (Annelida) phylogeny based on molecular data. Organisms, Diversity and Evolution

Beesley, P.L., Ross, G.J.B. & Glasby, C.J. (eds) 2000. Polychaetes & Allies: The Southern Synthesis. Fauna of Australia Vol. 4A Polychaeta, Myzostomida, Pogonophora, Echiura, Sipuncula. Melbourne : CSIRO Publishing Vol. 4 Part A xii 1-465 pp.

Glasby, C.J., Wei, N.V. & Gibb, K.S. 2013. Cryptic species of Nereididae (Annelida : Polychaeta) on Australian coral reefs. Invertebrate Systematics 27: 245–264

Wilson, R.S. 2000. Family Nereididae. pp. 138-141 in Beesley, P.L., Ross, G.J.B. & Glasby, C.J. (eds). Polychaetes & Allies: The Southern Synthesis. Fauna of Australia Vol. 4A Polychaeta, Myzostomida, Pogonophora, Echiura, Sipuncula. Melbourne : CSIRO Publishing Vol. 4 Part A xii 1-465 pp.

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