PORT PHILLIP BAY


Ragworm 

Olganereis edmondsi (Hartman, 1954)

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. Longest tentacular cirri extend back to chaetiger 3. Maxillary ring of pharynx with papillae; maxillary ring 4-7 papillae in total. Oral ring papillae present; solitary; 9-14 papillae present in total. Area V papillae absent; VI: 1; VII-VIII: 7-12 papillae. Transverse dorsal lamellae absent. 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 present. Dorsal cirrus not terminally attached to dorsal notopodial ligule on posterior chaetigers. Dorsal cirrus length about 2 times ventral notopodial ligule at chaetiger 10-20. Neuropodial postchaetal lobe present, at least on some anterior chaetigers. Ventral neuropodial ligule on posterior chaetigers reduced, up to half length of acicular neuropodial ligule. Ventral cirri single. Notopodial homogomph spinigers present. Notopodial homogomph falcigers absent. Neuropodial dorsal fascicle fused falcigers absent.

Taxonomy

Phylum:
Annelida
Class:
Polychaeta
Order:
Phyllodocida
Family:
Nereididae
Genus:
Olganereis
Species:
edmondsi

General Description

In members of this genus the eversible pharynx has papillae present on the oral ring only, and the maxillary ring (closest to the jaws) is bare of papillae. The only similar genus in southern Australia is Ceratocephale, but in that genus the prostomium is strongly indented between the antennae (in Olganereis it is entire). This species can be distinguished knowing that only a single species of Olganereis is known. Body up to about 4 cm long.

Biology

It is curious that this is one of a number of species that is only known to occur in coastal embayments yet is apparently absent from similar depths and environments on the nearby continental shelf.

Habitat

A common species in soft sediments in coastal bays, shallow subtidal, occassionally intertidal, to depth of about 20 m.

Soft substrates

Distribution guide

South-eastern Australia, or south-western Australia.

Species Group

Worms Ragworms

Depth

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

Water Column

On or near sea floor

Max Size

4 cm

Commercial Species

No

Species Code

MoV 1090

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, Olganereis edmondsi, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 29 May 2017, http://portphillipmarinelife.net.au:8098/species/7555

Text: creative commons cc by licence