PORT PHILLIP BAY


Sponge 

Darwinella australiensis Carter, 1885

View scientific description and taxonomy

Scientific Details

This genus group is characterised by having a fibrous skeleton free of sand or detritus, supplemented by collagenous spicules (as opposed to mineral-based siliceous or calcareous spicules). These fibrous spicules are found free in the collagen matrix. They may have two, three or more axes with tapering points and tend to be curved rather than straight, as those found in sponges with mineral-based spicules. Fibrous spicules appear the same density and colour as the fibres when viewed through a microscope. When distinguishing between species of Darwinella and Aplysilla, easily confused, the presence or absence of fibrous spicules is an important microscopic feature. Typically soft and fleshy, Darwinella species range in shape from encrusting to massive or lobate. They are often yellow or pink-red in colour.

Brief species characters:
Growth form: encrusting.
Mineral skeleton: absent.
Surface texture: conulose, glossy.

Family level characters:
The fibre skeleton of sponges in this family is always branching (dendritic), never mesh-like (reticulate). Darwinellid sponges are generally encrusting in habit but can be erect and branching. Of the four genera in this family, three are included here.

Order level characters:
Sponges of this collagenous order also lack spicules. They are often soft and very fragile due to a reduction in the fibrous skeleton in relation to the tissue mass. All begin their growth from a base that spreads over the substrate. The fibres of the skeleton then grow either in a branching, tree-like (dendritic) fashion (Family Darwinellidae), or adopt a mesh-like (reticulate) growth pattern (Family Dictyodendrillidae). The fibres of all sponges in this order show strong, concentric layering (lamination) and a very pronounced central core (pith), visible microscopically as a dark, opaque central line or region of collagen within the fibre. Examples of both families occur in southern Australian waters but only one family is included here.

Source: Goudie, L., Norman, M. N. and Finn, J. K. (in press) Sponges, Museum Victoria.

Taxonomy

Phylum:
Porifera
Class:
Demospongiae
Order:
Dendroceratida
Family:
Darwinellidae
Genus:
Darwinella
Species:
australiensis

General Description

A yellow sponge species with encrusting form. Size of about 40 cm.

Biology

This is common species in Victorian waters. If damaged or exposed to air, yellow specimens of these sponges typically turn dark purple. This colour change is termed aerophobic.

Habitat

Reef and jetty areas, at depths of 10-50 m.

Sponge gardens

Reefs

Distribution guide

Victoria.

Species Group

Sponges Demosponges

Depth

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

Water Column

On or near sea floor

Max Size

40 cm

Diet

Plankton or particles

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 Goudie, L.

Lisa Goudie is a consultant with expertise in sponge taxonomy.

citation

Cite this page as:
Goudie, L., 2011, Sponge, Darwinella australiensis, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 17 Aug 2017, http://portphillipmarinelife.net.au:8098/species/7665

Text: creative commons cc by licence