PORT PHILLIP BAY


Brown Seaweed 

Dictyota dichotoma

View scientific description and taxonomy

Scientific Details

The two pronged forking at the tips of blades is a distinctive feature for species in the Dictyoltales. Has a narrow frond form Dictyota dichotoma var. intricate which can be confused with Dictyota furcellata and can be distinguished by a distinctive is a hemispherical shaped cell at the apical tip which can be seen microscopically. Dictyota dichotoma has a lens shaped apical cell. The broad form may be confused with Dilophus robustus, which has more medullary (filamentous cells) layers (2-3 rather than 1) in the branch edges.

Main information sources:
Womersley, H.B.S., (1984-2003). The Marine Benthic Flora of Southern Australia. Part 1-3d. Govt. Printer, South Australia.
Baldock, R.N. 2010. Algae Revealed. South Australian State Herbarium. Website.
AlgaeBase. Website.

Taxonomy

Phylum:
Ochrophyta
Subphylum:
Phaeista
Superclass:
Fucistia
Class:
Phaeophyceae
Order:
Dictyotales
Family:
Dictyotaceae
Genus:
Dictyota
Species:
dichotoma

General Description

Broad, flattened fronds branching in an even fork (dichotomous) pattern. Tips (apices) of fronds rounded through to abruptly ending in a straight point (apiculate). Spots (sporangia) occur in a scattered pattern often in patches across the fronds. Holdfast root-like (rhizoidal). Iridescent blue (underwater), medium brown. Up to 20 cm long (thallus).

Biology

This seaweed is sometimes referred to as 'doubling weed' in reference to its evenly divided branching. It is thought to have potential medicinal use as anti-inflammatory.

Habitat

Tidal pools, shallow subtidal reef, to depth of 21 m.

Reefs

Coastal shores

Distribution guide

Worldwide.

Species Group

Seaweeds and seagrasses Brown algae

Depth

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

Water Column

On or near sea floor

Max Size

20 cm

Diet

Photosynthetic - sunlight

Commercial Species

No

Global Dispersal

Recorded in Australia

Identify

Conservation Status

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

Author

article author Pocklington, Jacqui

Jacqui Pocklington is a Research Associate with expertise in algal taxonomy.

citation

Cite this page as:
Pocklington, Jacqui, 2011, Brown Seaweed, Dictyota dichotoma, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 21 Oct 2017, http://portphillipmarinelife.net.au:8098/species/12334

Text: creative commons cc by licence