Part A | 6.3
122 Part A Marine Flora and Fauna
Uses and Compounds. Used as directly food, and the
extracts have antimicrobial and antioxidant [6.203, 698]
activity.
Punctaria latifolia Greville
Description. Frond oblong or obovate, medium
brown, complanate, simple, ovate to ligulate, thickish, gelatinous and tender, usually 520 .30/ cm long
and .1/ 26 cm broad, margin smooth to undulate,
with a short, slender, stipe and cuneate base, arising
from a small, discoid, rhizoidal holdfast .0:5/ 12
.3/ mm across; epiphytic (usually on Posidonia or
Heterozostera) or epilithic; growth diffuse. Structure
.2/ 46 cells and 80120 m thick, with a medulla
24 cells thick with few phaeoplasts, and a monostromatic cortex of isodiametric cells mostly of similar
size to the medullary cells, 1525 m across in surface
view, each with several discoid to irregularly shaped
phaeoplasts each with a pyrenoid; phaeophycean hairs
scattered, single or in small groups, 710 m in
diameter [6.753].
Habitat. On rocks in the upper intertidal down to several meters depth.
Distribution. Widely distributed in cooler temperate
waters.
Uses and Compounds. Extracts have antibacterial [6.735], antiviral [6.735], cytotoxic, and antitumor [6.102, 735, 751, 754] activity.
Scytosiphon lomentaria (Lyngbye) Link
Common Name. Sausage weed
Description. S. lomentaria has cylindrical, shiny, olive
brown, unbranched fronds up to 400 mm long. They
have short stalks and a large number may arise from
a single discoid holdfast. They widen to 310 mm and
narrow again near the tip. They are hollow and often
have irregular constrictions [6.755].
Habitat. It occurs in the littoral zone on wave-exposed
shores and rock pools. Small plants are often found
growing on limpets and pebbles.
Distribution. Cosmopolitan in temperate and cold
seas.
Uses and Compounds. Used directly as food, and the
extracts have antioxidant [6.111, 112, 335, 756, 757],
antiviral [6.278], antimicrobial [6.421, 698], antitumor [6.421, 758], and antifouling [6.759] activity.
Order: Fucales
Ascophyllum nodosum (Linnaeus) Le Jolis
Common Names. Knotted wrack, Asco, Sea Whistle,
Bladderwrack, Egg wrack.
Description. A. nodosum is a perennial brown intertidal seaweed species most abundant on sheltered
rocky shores in the mid-intertidal zone of the North
Atlantic. Olive green in color, A. nodosum generally
grows upward in the water column anchoring to hard
substrates using a disk-shaped holdfast (Fig. 6.46).
A single specimen resembles an intertwined mass of
shoots and branches. Incoming tides gradually refloat vast stands of A. nodosum, until it becomes
an expansive swaying undersea forest. Its thallus can
measure from 30 to 60 cm, and is flexible to decrease breakage that may result from strong wave
action. Its long, thick, leathery, branching strap-like
fronds are typically between 0:5 and 2 m in length,
and have large egg-shaped air bladders (pneumatocysts) at regular intervals along their length which
keep the plant floating upright when submerged at
high tide, and hang downward, draping over intertidal rocks in a thick, tangled, and glistening mat at
low tide. The large air bladders take it toward the
light for maximum photosynthesis. The fronds have no
midrib.
It is present and grows all year round, and has no
resting period. The species grows slowly and can live
to be several decades old in wave-sheltered locations
of temperate waters, and it has the capability to survive low temperatures. It can eventually grow to three
and four meters; individual fronds can become up to 15
years old before breakage. The holdfasts of A. nodosum
are thought to persist for several decades from which
new fronds regenerate. Another interesting attribute of
A. nodosum is that it repeatedly sloughs its entire outer
epidermis, a phenomenon not exhibited by other related
seaweeds.
A. nodosum attaches to rocks and boulders on the
middle shore in a range of habitats, from estuaries to
relatively exposed coasts. These sites can have low,
moderate, and high wave action across low-, mid- and
upper littoral heights, although some sublittoral populations have been reported. The upper limits of A.
nodosum distribution are controlled by its ability to resist desiccation and high temperatures [6.1, 760].
122 Part A Marine Flora and Fauna
Uses and Compounds. Used as directly food, and the
extracts have antimicrobial and antioxidant [6.203, 698]
activity.
Punctaria latifolia Greville
Description. Frond oblong or obovate, medium
brown, complanate, simple, ovate to ligulate, thickish, gelatinous and tender, usually 520 .30/ cm long
and .1/ 26 cm broad, margin smooth to undulate,
with a short, slender, stipe and cuneate base, arising
from a small, discoid, rhizoidal holdfast .0:5/ 12
.3/ mm across; epiphytic (usually on Posidonia or
Heterozostera) or epilithic; growth diffuse. Structure
.2/ 46 cells and 80120 m thick, with a medulla
24 cells thick with few phaeoplasts, and a monostromatic cortex of isodiametric cells mostly of similar
size to the medullary cells, 1525 m across in surface
view, each with several discoid to irregularly shaped
phaeoplasts each with a pyrenoid; phaeophycean hairs
scattered, single or in small groups, 710 m in
diameter [6.753].
Habitat. On rocks in the upper intertidal down to several meters depth.
Distribution. Widely distributed in cooler temperate
waters.
Uses and Compounds. Extracts have antibacterial [6.735], antiviral [6.735], cytotoxic, and antitumor [6.102, 735, 751, 754] activity.
Scytosiphon lomentaria (Lyngbye) Link
Common Name. Sausage weed
Description. S. lomentaria has cylindrical, shiny, olive
brown, unbranched fronds up to 400 mm long. They
have short stalks and a large number may arise from
a single discoid holdfast. They widen to 310 mm and
narrow again near the tip. They are hollow and often
have irregular constrictions [6.755].
Habitat. It occurs in the littoral zone on wave-exposed
shores and rock pools. Small plants are often found
growing on limpets and pebbles.
Distribution. Cosmopolitan in temperate and cold
seas.
Uses and Compounds. Used directly as food, and the
extracts have antioxidant [6.111, 112, 335, 756, 757],
antiviral [6.278], antimicrobial [6.421, 698], antitumor [6.421, 758], and antifouling [6.759] activity.
Order: Fucales
Ascophyllum nodosum (Linnaeus) Le Jolis
Common Names. Knotted wrack, Asco, Sea Whistle,
Bladderwrack, Egg wrack.
Description. A. nodosum is a perennial brown intertidal seaweed species most abundant on sheltered
rocky shores in the mid-intertidal zone of the North
Atlantic. Olive green in color, A. nodosum generally
grows upward in the water column anchoring to hard
substrates using a disk-shaped holdfast (Fig. 6.46).
A single specimen resembles an intertwined mass of
shoots and branches. Incoming tides gradually refloat vast stands of A. nodosum, until it becomes
an expansive swaying undersea forest. Its thallus can
measure from 30 to 60 cm, and is flexible to decrease breakage that may result from strong wave
action. Its long, thick, leathery, branching strap-like
fronds are typically between 0:5 and 2 m in length,
and have large egg-shaped air bladders (pneumatocysts) at regular intervals along their length which
keep the plant floating upright when submerged at
high tide, and hang downward, draping over intertidal rocks in a thick, tangled, and glistening mat at
low tide. The large air bladders take it toward the
light for maximum photosynthesis. The fronds have no
midrib.
It is present and grows all year round, and has no
resting period. The species grows slowly and can live
to be several decades old in wave-sheltered locations
of temperate waters, and it has the capability to survive low temperatures. It can eventually grow to three
and four meters; individual fronds can become up to 15
years old before breakage. The holdfasts of A. nodosum
are thought to persist for several decades from which
new fronds regenerate. Another interesting attribute of
A. nodosum is that it repeatedly sloughs its entire outer
epidermis, a phenomenon not exhibited by other related
seaweeds.
A. nodosum attaches to rocks and boulders on the
middle shore in a range of habitats, from estuaries to
relatively exposed coasts. These sites can have low,
moderate, and high wave action across low-, mid- and
upper littoral heights, although some sublittoral populations have been reported. The upper limits of A.
nodosum distribution are controlled by its ability to resist desiccation and high temperatures [6.1, 760].