PORT PHILLIP BAY


Sea Lettuce 

Ulva lactuca

View scientific description and taxonomy

Scientific Details

Similar to other species in the genus Ulva and most reliably distinguished by microscopic examination of cells.

Ulva australis: several sheet-like blades, blade edges without minute teeth, 2 sheets of cells that are longer than broad.

Ulva compressa: single sheet-like blade or cylindrical, ribbon-like branched form, cells in short lines or unordered.

Ulva lactuca: single sheet-like blade, edges without minute teeth, 2 layers of box-shaped cells.

Ulva linza: single paddle-like blade, cells square to rectangular in lines or arcs.

Ulva rigida: single sheet-like blade, edges with minute teeth, 2 layers of elongated, tapered cells.

Ulva taeniata: several narrow blades, edges with minute teeth, 2 layers of elongated, rounded cells.

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:
Chlorophyta
Subphylum:
Tetraphytina
Class:
Ulvophyceae
Order:
Ulvales
Family:
Ulvaceae
Genus:
Ulva
Species:
lactuca

General Description

Lobed, smooth, broad and thin, flattened surface (sheet-like) as a single frond arising from holdfast. Holdfast at base is small with root-like (rhizoidal) extensions in lower cells. Grass green. Up to 15 cm long (thallus).

Biology

This green alga often grows on invertebrates and other algae/seagrass species. It is less common than other Ulva species. High numbers of this species form blooms seasonally and in areas of high nutrients such as near stormwater, stream run-off and sewerage outfalls.

Habitat

Intertidal and subtidal rocky reefs, common in shallow waters, to depth of 6 m.

Reefs

Coastal shores

Distribution guide

Worldwide.

Species Group

Seaweeds and seagrasses › Green algae

Depth

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

Water Column

On or near sea floor

Max Size

15 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, Sea Lettuce, Ulva lactuca, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 26 Jun 2025, http://136.154.202.208:8098/species/11147

Text: creative commons cc by licence