Part A | 6.3
80 Part A Marine Flora and Fauna
The thalli are unbranched and often have a frilled margin. The thalli taper into a distinct stipe below and are
highly compressed. The width of the thallus is greater
in the middle than at the base and may reach 5 cm
in width. U. linza is bright light to dark green in coloration [6.32, 274].
Habitat. Usually found on rocks or in rock pools,
usually marine but occasionally found under brackish
conditions.
Distribution. U. linza is found worldwide in bays and
sheltered coasts.
Uses and Compounds. U. linza is used as an edible
seaweed in many cultures for its high nutrient content
and silky texture. Green algae extracts are also very
nutrient rich and make a beneficial addition to natural
cosmetic products [6.274]. Have antibacterial [6.60, 96,
228, 269, 275, 276], anti-inflammatory [6.277], and antiviral [6.278].
Ulva prolifera O.F. Müller
Synonym. Enteromorpha prolifera (O.F. Müller)
J. Agardh
Common Name. Green ribbon plant.
Description. The fronds are tubular, though often
more or less flattened, little to much branched. The arrangement of the cells, in longitudinal and transverse
rows in the central part of the frond, is characteristic of this species, as are the cylindrical chloroplasts
seeming to fill the cell and the usually single, central
pyrenoids [6.279].
Habitat. A common green alga near the top of the
shore, on rocks or other algae, on open coasts or
in estuaries and harbors, where it may grow mixed
with U. intestinalis or other species of the same
genus.
Distribution. NE Atlantic (Britain to Senegal); Atlantic Islands, Mediterranean; NW and W Atlantic;
Caribbean; SE Atlantic; Pacific; China, Australia.
Uses and Compounds. Used for food [6.280] and
animal feed [6.281, 282]; potential use for the production of biofuels [6.283]. Have also antibacterial [6.171,
284], antifouling [6.285], antioxidant [6.101], antifungal [6.226, 286], antitumor [6.126], immunomodulatory [6.287] activity.
Ulva rigida C. Agardh
Common Name. Green laver.
Description. U. rigida is a bright green seaweed with
a variety of growth forms. The two cell layer thick,
sheet-like blades can grow as tiny blades forming
carpet-like turfs, or as clumps of several larger blades,
or solitarily. In its largest form, Ulva rigida can reach
up to 10 cm in height, but size and blade shape are
both highly variable. Blades may be flat or ruffled,
sometimes bearing many small holes (perforations)
and sometimes not. However, the defining characteristics of U. rigida are common among all its growth
forms: the two cell layers of the blades are easily separable, like a deflated balloon, and the holdfasts are
composed of many small, tough, dark rhizhoids that
are absent in other Ulva species. U. rigida is common in intertidal and shallow sublittoral waters, often
found in tidepools. This seaweed is able to withstand
high variation in salinity and water chemistry and actually seems to prefer areas with freshwater input [6.32,
288].
Habitat. Epilithic, in the entire littoral zone to the
sublittoral.
Distribution. U. rigida has a worldwide distribution
in temperate and warm seas.
Uses and Compounds. U. rigida is often utilized
as a fresh sea vegetable by many island cultures
for its high nutrient content and fresh taste [6.288,
289]. This species is used to for animal feed [6.290,
291].
Green algae extracts are also very nutrient-rich
and make a beneficial addition to natural cosmetic
products. The polysaccharide ulvan is easily extracted
from U. rigida. It is composed of ˇ-(1,4)-xyloglucan,
glucuronan, and cellulose in a linear arrangement. It
corresponds to a water-soluble dietary fiber and is
resistant to both human digestive tract enzymes and
degradation by colonic bacteria. This polysaccharide
cannot therefore be considered prebiotic; however, it
could potentially be hydrolyzed to bioactive oligosaccharides [6.288, 292].
U. rigida have antigenotoxicity [6.293, 294], antihyperglycemic [6.293], immunomodulating [6.295],
80 Part A Marine Flora and Fauna
The thalli are unbranched and often have a frilled margin. The thalli taper into a distinct stipe below and are
highly compressed. The width of the thallus is greater
in the middle than at the base and may reach 5 cm
in width. U. linza is bright light to dark green in coloration [6.32, 274].
Habitat. Usually found on rocks or in rock pools,
usually marine but occasionally found under brackish
conditions.
Distribution. U. linza is found worldwide in bays and
sheltered coasts.
Uses and Compounds. U. linza is used as an edible
seaweed in many cultures for its high nutrient content
and silky texture. Green algae extracts are also very
nutrient rich and make a beneficial addition to natural
cosmetic products [6.274]. Have antibacterial [6.60, 96,
228, 269, 275, 276], anti-inflammatory [6.277], and antiviral [6.278].
Ulva prolifera O.F. Müller
Synonym. Enteromorpha prolifera (O.F. Müller)
J. Agardh
Common Name. Green ribbon plant.
Description. The fronds are tubular, though often
more or less flattened, little to much branched. The arrangement of the cells, in longitudinal and transverse
rows in the central part of the frond, is characteristic of this species, as are the cylindrical chloroplasts
seeming to fill the cell and the usually single, central
pyrenoids [6.279].
Habitat. A common green alga near the top of the
shore, on rocks or other algae, on open coasts or
in estuaries and harbors, where it may grow mixed
with U. intestinalis or other species of the same
genus.
Distribution. NE Atlantic (Britain to Senegal); Atlantic Islands, Mediterranean; NW and W Atlantic;
Caribbean; SE Atlantic; Pacific; China, Australia.
Uses and Compounds. Used for food [6.280] and
animal feed [6.281, 282]; potential use for the production of biofuels [6.283]. Have also antibacterial [6.171,
284], antifouling [6.285], antioxidant [6.101], antifungal [6.226, 286], antitumor [6.126], immunomodulatory [6.287] activity.
Ulva rigida C. Agardh
Common Name. Green laver.
Description. U. rigida is a bright green seaweed with
a variety of growth forms. The two cell layer thick,
sheet-like blades can grow as tiny blades forming
carpet-like turfs, or as clumps of several larger blades,
or solitarily. In its largest form, Ulva rigida can reach
up to 10 cm in height, but size and blade shape are
both highly variable. Blades may be flat or ruffled,
sometimes bearing many small holes (perforations)
and sometimes not. However, the defining characteristics of U. rigida are common among all its growth
forms: the two cell layers of the blades are easily separable, like a deflated balloon, and the holdfasts are
composed of many small, tough, dark rhizhoids that
are absent in other Ulva species. U. rigida is common in intertidal and shallow sublittoral waters, often
found in tidepools. This seaweed is able to withstand
high variation in salinity and water chemistry and actually seems to prefer areas with freshwater input [6.32,
288].
Habitat. Epilithic, in the entire littoral zone to the
sublittoral.
Distribution. U. rigida has a worldwide distribution
in temperate and warm seas.
Uses and Compounds. U. rigida is often utilized
as a fresh sea vegetable by many island cultures
for its high nutrient content and fresh taste [6.288,
289]. This species is used to for animal feed [6.290,
291].
Green algae extracts are also very nutrient-rich
and make a beneficial addition to natural cosmetic
products. The polysaccharide ulvan is easily extracted
from U. rigida. It is composed of ˇ-(1,4)-xyloglucan,
glucuronan, and cellulose in a linear arrangement. It
corresponds to a water-soluble dietary fiber and is
resistant to both human digestive tract enzymes and
degradation by colonic bacteria. This polysaccharide
cannot therefore be considered prebiotic; however, it
could potentially be hydrolyzed to bioactive oligosaccharides [6.288, 292].
U. rigida have antigenotoxicity [6.293, 294], antihyperglycemic [6.293], immunomodulating [6.295],