PORT PHILLIP BAY


Hydroid 

Silicularia rosea (Meyen, 1834)

View scientific description and taxonomy

Scientific Details

Family level detail.
Hydroids with a simple bell-shaped (campanulate) hydrotheca without operculum. Apertural rim of hydrotheca may be smooth, toothed, crenulated or cuspate. Gonophores protected by a gonotheca. Hydroids of the family Campanulariidae are common throughout the world. Many species form large, spreading colonies comprising many simple stems arising from a creeping network of stolons. Other species from large, multi-branched colonies, usually lacy in appearance. Medusae range in structure from primitive eumedusoids that swim only feebly to fully formed free-swimming medusae.

Genus level detail.
Colony stolonal, hydrotheca asymmetrical, with markedly thickened walls, apertural rim sloping, hydranth not completely retractable into hydrotheca, gonotheca borne on hydrorhiza, gonophore primitive eumedusoid. The genus Silicularia has only two known species: Silicularia rosea and Silicularia undulata, both of which are cool-temperate to Antarctic in distribution, both occurring in southern Australia. The species can be distinguished by their habitat preference.

Species identification.
Hydrorhiza ribbon-like, firmly attached to substrate, hydrothecal pedicels given off singly from hydrorhiza, short, smooth, a spherule below hydrotheca. Hydrotheca conical, one wall shorter and thicker than the other imparting a decidedly lopsided appearance. Female gonotheca tall, cylindrical to conical with a circular terminal aperture, male gonotheca smaller, flattened to substrate. Gonophore releases a larva. Colour: colonies white.

Taxonomy

Phylum:
Cnidaria
Class:
Hydrozoa
Subclass:
Leptothecatae
Order:
Proboscoida
Family:
Campanulariidae
Genus:
Silicularia
Species:
rosea

General Description

Colony of individual polyps (hydranths) joined by root-like network of tubular stolons at the base. Colony shape is simple. Colour: colonies white.

Biology

This species grows annually over summer.

Habitat

On fronds and stems of large brown kelps.

Reefs

Distribution guide

New Zealand and southern Australia.

Species Group

Hydroids

Depth

Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

Diet

Plankton or Particles

Harmful

Generally not harmful but still able to sting bare skin.

Commercial Species

No

Global Dispersal

Recorded in Australia

Species Code

MoV 3457

Identify

Conservation Status

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

Author

article author Watson, J.

Jan Watson is a consultant with expertise in hydroid taxonomy.

citation

Cite this page as:
Watson, J., 2011, Hydroid, Silicularia rosea, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 19 Oct 2017, http://portphillipmarinelife.net.au:8098/species/7139

Text: creative commons cc by licence