PORT PHILLIP BAY


Chiton 

Rhyssoplax tricostalis (Pilsbry, 1894)

View scientific description and taxonomy

Scientific Details

Suborder and Family level characters:
Tegmentum always present.
Anterior valve with 6 or more slits.
Insertion plates pectinate

Species level characters:
Middle valves with about 15 longitudinal ridges in the central area, and with ridges with knobs (nodulose) radiating outward to the edges (lateral areas). Raised section (keel) along middle of valves from anterior to posterior. Girdle covered with overlapping (imbricate) scales, each scale with fine lines (striate).

Sources:
Macpherson, J. H. and Gabriel, C. J. (1962) Marine Molluscs of Victoria.
Kass, P., Jones, A. M. and Gowlett-Holmes, K. L. (1998) Polyplacophora, in: Mollusca: the southern synthesis, Australian Biological Resources Study.

Taxonomy

Phylum:
Mollusca
Class:
Polyplacophora
Order:
Neoloricata
Suborder:
Ischnochitonina
Family:
Chitonidae
Subfamily:
Chitoninae
Genus:
Rhyssoplax
Species:
tricostalis

General Description

Flattened oval shaped body with 8 shell sections (valves) surrounded by a fleshy girdle. Colour variable, including brown, green or red, or second and third valves white. Up to 3 cm long.

Biology

This uncommon species has one of the more rough, sculptured shells among the chiton group. It grazes on algae, encrusting invertebrates and sponges for food.

Habitat

Under rocks, below low tide level to depth of 20 m.

Reefs

Coastal shores

Sponge gardens

Distribution guide

Southern Australia, including western and central Victoria.

Species Group

Sea snails and shells › Chitons

Depth

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

Water Column

On or near sea floor

Max Size

3 cm

Diet

Omnivore

Commercial Species

No

Global Dispersal

Native to Australia

Identify

Conservation Status

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

Author

article author Patullo, B.

Blair Patullo is Online Producer for marine projects at Museum Victoria.

citation

Cite this page as:
Patullo, B., 2011, Chiton, Rhyssoplax tricostalis, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 25 Feb 2025, http://136.154.202.208:8098/species/5692

Text: creative commons cc by licence