PORT PHILLIP BAY


Dark-marked Scale Worm 

Lepidonotus melanogrammus Haswell, 1883

View scientific description and taxonomy

Scientific Details

Family level description.
Polynoidae are predators in which the dorsal cirri of an alternating series of segments are modified to form scales which lie flat covering the top of the worm and make two rows like overlapping tiles on a roof. The scales (elytrae) are typically pigmented and/or pigmented in distinctive, species-specific patterns. The commonly-observed shallow water species are mostly short-bodied, often with a fixed number of segments and elytrae. Anteriorly the prostomium and appendages are varied but generally a a pair of large conical palps and pairs of antennae and tentacular cirri can be seen (although the anterior-most scales usually have to be removed to reveal these structures). The muscular eversible pharynx, if dissected, can be seen to have two pairs of jaws that close in a vertical plane. Chaetae are generally numerous and conspicuous, always simple (compound chaetae are absent) and ornamented with a diverse array of spines, teeth and other gothic ornaments.

Species level technical description.
Elytrae number 12 pairs. Elytra present on chaetigers 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23. Last pair on the expected chaetiger; present to posterior end ( 3 or fewer segments without elytrae); Elytrae large but leaving middle of dorsum uncovered. Elytral coloration: With 3 connected crescent shaped brown pigmented areas plus a 4th crescent shaped brown pigmented area separate from the others; pigmented areas consisting of irregular polygons. Elytral surface ornamentation present as microtubercles. Distal end of microtubercles simple, or with ridges, teeth or spines; soft-walled. Hemisphaerical; without stalk. Microtubercles distally quadrifid to multifid. Elytral pockets absent. Free margin without papillae (fimbriae). Elytrae flat or undulating.

Taxonomy

Phylum:
Annelida
Class:
Polychaeta
Order:
Phyllodocida
Family:
Polynoidae
Genus:
Lepidonotus
Species:
melanogrammus

General Description

In members of this genus there are 12 pairs of elytrae and 26 segments. This species is the only polynoid with uniform very dark grey pigmentation throughout. This species has 2-3 dark pigmented crescents on each elytron, resulting in a very distinctive dorsal pattern. The elytrae are smooth. Body up to about 5 cm long.

Biology

This scale worm is very often seen crawling over the banded brittle star (Ophionereis schayeri) but the nature of the association between the two species is unknown. Both the brittle star and the scale worm can also often be found by themselves.

Habitat

Port Phillip Bay and other similar coastal habitat, inshore and continental shelf.

Reefs

Soft substrates

Distribution guide

Southern Australia.

Species Group

Worms Scaleworms

Depth

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

Water Column

On or near sea floor

Max Size

5 cm

Diet

Carnivore

Commercial Species

No

Global Dispersal

Native to Australia

Species Code

MoV 4132

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, Dark-marked Scale Worm, Lepidonotus melanogrammus, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 21 Jul 2017, http://portphillipmarinelife.net.au:8098/species/7587

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