font settings and languages

Font Size: Large | Normal | Small
Font Face: Verdana | Geneva | Georgia
Languages:

Undaria pinnatifida

(Apron-Ribbon Vegetable, Asian Kelp, Ito-Wakame, Japanese Kelp)

Overview

[ Back to top ]

Aquatic Plant. A kelp native to Japan where it is cultivated for human consumption . It is an opportunistic weed which spreads mainly by fouling ship hulls. It forms dense forests , resulting in competition for light and space which may lead to the exclusion or displacement of native plant and animal species. Overwhelmingly the main use of undaria is as human food. It is essentially a staple of the Japanese and Korean diets and is also widely consumed in Japan.

Common Names

[ Back to top ]

Click on the language to view common names.

Common Names in Chinese:

Haijiecai, Quandaicai

Common Names in English:

Apron-Ribbon Vegetable, Asian Kelp, Ito-Wakame, Japanese Kelp

Common Names in Japanese:

Kada-Me, Niki-Me, Wakame

Common Names in Korean:

Miyeuk

Description

[ Back to top ]

Physical Description

Species Undaria pinnatifida

Undaria pinnatifida is a brown seaweed that can reach an overall length of 1-3 metres . It is an annual species with two separate life stages. The macroscopic stage (the sporophyte), usually present through the late winter to early summer months and a microscopic stage (the gametophyte), present during the colder months.
The sporophyte is golden-brown in colour , with a lighter coloured stipe.It has a strap-like midrib full length of thallus, 1-3 cm wide; edges of midrib expanded as thin membranous pinnatifid blade ; pinnnae 50-80 cm long, blade dotted with white cryptostomata and dark gland cells , terminates well short of base ; naked basal section of midrib forms stipe. As sporophytes mature two thickened fluted sporophylls develop, one along each edge of stipe, and bend laterally around stipe with folds becoming interleaved , always in two discrete pieces .The gametophyte is microscopic.
The spiral sporophyll and the midrib are the key identification features.

Habitat

Undaria pinnatifida is described as an opportunistic seaweed able to rapidly colonise new or disturbed substrata and artificial floating structures. It occures in dense, vigorous stands on benthic shores , forming thick canopy over the biota in a wide range of shores varying in exposure, from low tide level down to 15 m in clear waters.
Undaria inhabits cold temperate coastal areas and grows best in waters below 12° C. Sporophytes are reported to degrade at temperatures above 20° C and die at temperatures greater than 23° C. Undaria pinnatifida grows in a wide range of wave exposures from sheltered marinas to the open coast, and extends vertically from the low intertidal to 18 m depth (although it is most common between 1 and 3 m depth). It tolerates a wide range of irradiance from full sunlight to very low light levels, but is unlikely to invade areas with a high fresh water input.
Undaria can grow on any hard surface including artificial substrates such as rope, pylons, buoys, the hulls of vessels , bottles, floating pontoons and plastic. On natural substrates, undaria inhabits stable rocky reefs, mobile cobble habitats , mudstone, and in primarily soft sediment habitats attaches to hard surfaces such as shell . It can also grow on seagrass (while a small sporophyte), the shells of abalone and bivalves , invertebrates and epiphytically on other seaweeds (MFish, 2001).

Typically found in water with a depth of 0 to -70 meters (0 to -230 feet).Mean = -17.670 meters (-57.972 feet), Standard Deviation = 45.790 based on 3 observations. Ocean depth information for each observation from British Oceanographic Data Centre.

Biome: marine habitats

Ecology: The impacts of Undaria pinnatifida are not well understood and are likely to vary considerably depending on the location. Undaria can change the structure of ecosystems, especially in areas where native seaweeds are absent (Mfish, 2001).
NIMPIS, 2002 states that U. pinnatifida has the potential to become a problem for marine farms by increasing labour and harvesting costs due to fouling problems on fin fish cages , oyster racks , scallop bags and mussel ropes. Heavy fouling may also restrict water flow through cages.
The Department of Conservation in its brochure "Gorse of the Sea" state that undaria could foul mussel farms, salmon farms and boats . Heavy infestations of undaria may also clog marine farming machinery, slow growth of mussels and restrict water circulation.Heavy fouling of boats seriously decreases their efficiency.

Biology

[ Back to top ]

Reproduction

Asexual/sexual. Annual heteromorphic life cycle alternative between the diploid macroscopic sporophyte and the haploid microscopic gametophyte (NIMPIS, 2002).The life cycle of Undaria pinnatifida is complex . The macroscopic sporophytes grow during winter and release spores as summer approaches.These spores which are microscopic disperse and settle down to germinate into gametophytes, when conditions are favourable these gametophytes produce sperms and eggs which fertilise and grow into the plant ie. the sporophyte.
Temperature, light and depth are all important cues in development (NIMPIS, 2002).

Taxonomy

[ Back to top ]

Unambiguous Synonyms

  1. Alaria pinnatifida Harvey
  2. Ulopteryx pinnatifida (Harvey) Kjellman
  3. Undaria pinnatifida (Harv.) W.F.R. Suringar
  4. Undaria pinnatifida (Harvey) Suringar

Similar Species

[ Back to top ]

Members of the genus Undaria

There are approximately 9 species in this genus:

U. agaricites · U. crassa · U. crenata · U. peterseniana · U. pinnatifia · U. pinnatifida (Apron-Ribbon Vegetable) · U. pinnatifida var. elongata · U. pinnatifida var. vulgaris · U. undarioides

More Info

[ Back to top ]

Notes

[ Back to top ]

Contributors

Data Sources

Accessed through GBIF Data Portal May 14, 2008:

Identifiers

Footnotes

Last Revised: 2008-08-05