PORT PHILLIP BAY


Ragworm 

Nereis bifida Hutchings & Turvey, 1982

View scientific description and taxonomy

Scientific Details

Family level description.
Nereididae are polychaetes with many uniform segments, without strongly differentiated body regions. The prostomium (head) has one pair of antennae, one pair of articulated palps, and two pairs of eyes. Four pairs of unjointed cirri emerge from the next segment behind the prostomium. Mouthparts comprise an eversible pharynx with one pair of terminal jaws, although these are usually only visible by dissection.

Species level technical description.
Prostomium with entire anterior margin. Area I bare, II: 0-9 conical paragnaths; III: 0-3; IV: 5-10. Area V conical paragnaths absent; VI: 1-3; VII-VIII: 1-8 (generally 3-5, always in a single row). Dorsal notopodial ligule not markedly elongate on posterior chaetigers. Not markedly broader on posterior chaetigers. Dorsal notopodial ligule markedly reduced on posterior chaetigers. Prechaetal notopodial lobe absent. Dorsal cirrus not terminally attached to dorsal notopodial ligule on posterior chaetigers. Dorsal cirrus length about 1.5-2 times ventral notopodial ligule at chaetiger 10-20. Neuropodial postchaetal lobe absent. Ventral neuropodial ligule on posterior chaetigers similar to length of acicular neuropodial ligule. Ventral cirri single. Notopodial homogomph spinigers present; sesquigomph spinigers absent. Notopodial homogomph falcigers present; first present at chaetiger 18. Notopodial homogomph falcigers articulated throughout. Notopodial homogomph falcigers bidentate, with large adjacent terminal and subterminal teeth. Neuropodial dorsal fascicle fused falcigers absent.

Taxonomy

Phylum:
Annelida
Class:
Polychaeta
Order:
Phyllodocida
Family:
Nereididae
Genus:
Nereis
Species:
bifida

General Description

In members of this genus there are short-bladed chaetae with a distinctive ball-and-socket articulation present in the dorsal bunch of chaetae on most segments starting at about 12-15 (these are referred to as "homogomph falcigers" in technical descriptions). Paragnaths are present, usually on both rings of the eversible phayrnx. This species can be distinguished by the absence of paragnaths on the oral ring. Two common Nereis species have bifid dorsal chaetae: Nereis bifida has paragnaths on most areas of the pharynx, while in Nereis maxillodentata the entire oral ring is bare of paragnaths. Body up to about 4 cm long.

Biology

Nereis bifida and Nereis maxillodentata are the two species of Nereis most commonly collected in southern Australia.

Habitat

Collected from a wide variety of habitats, intertidal to 200 m, occasionally deeper than 200 m.

Reefs

Seagrass meadows

Soft substrates

Distribution guide

South-eastern Australia, or south-western Australia.

Species Group

Worms Ragworms

Depth

Shore (0-1 m)
Shallow (1-30 m)
Deep ( > 30 m)

Water Column

On or near sea floor

Max Size

4 cm

Commercial Species

No

Global Dispersal

Recorded in Australia

Species Code

MoV 402

Identify

Conservation Status

  • DSE Advisory List : Not listed
  • EPBC Act 1999 : Not listed
  • IUCN Red List : Not listed

Author

article author Wilson, R.

Robin Wilson is a Senior Curator of marine invertebrates at Museum Victoria.

citation

Cite this page as:
Wilson, R., 2011, Ragworm, Nereis bifida, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 26 May 2017, http://portphillipmarinelife.net.au:8098/species/7550

Text: creative commons cc by licence