MARELAC ` BOTANY` 2
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Transcript MARELAC ` BOTANY` 2
1.b. Macroalgae
In freshwater biota: Charophytes limited to
oligotrophic, alkaline waters.
Charophyta: left: dense vegetation;
Right: detail.
1.b. Macroalgae
In freshwater biota: limited: Charophytes
• Along coastlines: on rocky substrate + in mangroves +
in salt marshes + on seagrasses.
Rocky shore with extensive macroalgal (seaweed) vegetations.
Mangrove with aerial roots (pneumatophores) densely covered by epiphytic
algae, mainly red algae (Rhodophyta).
Seaweed growth in a young salt marsh vegetation (Salicornia europaea).
Macroalgae in seagrass vegetations:
the brown alga Dictyota epiphytic on
Thalassodendron ciliatum.
1.b. Macroalgae
In freshwater biota: limited: Charophytes
•
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
• Plant body = thallus: NO vascular bundles (no "true"
roots, stems nor leaves although they can look like -);
NO flowers; NO seeds (spores!).
Chlorophyta: Caulerpa sertularioides: structures SIMILAR to
higher plants: stolonoïds, rhizoïds and feathery assimilators.
Phaeophyta: Laminaria:
structures SIMILAR to higher
plants: haptera, stipe and blade.
Rhodophyta: Zellera tawallina with holdfast, stem-like and bladelike structures.
1.b. Macroalgae
In freshwater biota: limited: Charophytes
•
•
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor
leaves); NO flowers; NO seeds (spores!).
• Photosynthesis and uptake of nutrients by whole
thallus.
1.b. Macroalgae
In freshwater biota: limited: Charophytes
•
•
•
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor leaves);
NO flowers; NO seeds (spores!).
Photosynthesis and uptake of nutrients by whole thallus.
• Underestimated in biodiversity discussions ("invisible").
1.b. Macroalgae
In freshwater biota: limited: Charophytes
•
•
•
•
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor
leaves); NO flowers; NO seeds (spores!).
Photosynthesis and uptake of nutrients by whole thallus.
Underestimated in biodiversity discussions ("invisible").
• Requirements for development:
* Salt or brackish water (rare exceptions);
1.b. Macroalgae
In freshwater biota: limited: Charophytes
•
•
•
•
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor
leaves); NO flowers; NO seeds (spores!).
Photosynthesis and uptake of nutrients by whole thallus.
Underestimated in biodiversity discussions ("invisible").
• Requirements for development:
* Salt or brackish water (rare exceptions);
* Submerged, at least part of the day;
1.b. Macroalgae
In freshwater biota: limited: Charophytes
•
•
•
•
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor
leaves); NO flowers; NO seeds (spores!).
Photosynthesis and uptake of nutrients by whole thallus.
Underestimated in biodiversity discussions ("invisible").
• Requirements for development:
* Salt or brackish water (rare exceptions);
* Submerged, at least part of the day;
* Hard substrate: lithophytes (few exceptions: special
anchorage).
1.b. Macroalgae
Species diversity: approximate numbers
• Red (Rhodophyta = ± 4000-6000 spp), green
(Chlorophyta (macroalgae only!) = ± 2000 spp (+
microalgae = ~ 15000) and brown (Phaeophyta = ±
900-1500 spp) algae [and blue-greens: see micro-algae].
1.b. Macroalgae
Species diversity: approximate numbers
•
Red (Rhodophyta = ± 4000-6000 spp), green (Chlorophyta (macroalgae only!)
= ± 2000 spp (+ microalgae = ~ 15000) and brown (Phaeophyta = ± 900-1500
spp) algae [and blue-greens: see micro-algae].
• Some area's more species rich than others: Pacific:
Philippines, Japan; Atlantic: Europe!! (N-Spain,
France, UK); Caribbean!! Red Sea & Indian Ocean??
South Africa!! (different climate zones).
1.b. Macroalgae
Species diversity: approximate numbers
•
•
Red (Rhodophyta = ± 4000-6000 spp), green (Chlorophyta (macroalgae only!)
= ± 2000 spp (+ microalgae = ~ 15000) and brown (Phaeophyta = ± 900-1500
spp) algae [and blue-greens: see micro-algae].
Some area's more species rich than others: Pacific: Philippines, Japan;
Atlantic: Europe!! (N-Spain, France, UK); Caribbean!! Red Sea & Indian
Ocean?? South Africa!! (different climate zones)
• Most species rich: not tropics >< terrestrial plants.
Chlorophyta (green algae)
• More closely related to higher plants than to the
brown or red algae!!: photosynthesis by
chlorophyll a & b, storage product = starch, cell
wall component: cellulose.
Chlorophyta (green algae)
•
More closely related to higher plants than to the brown or red
algae!!: photosynthesis by chlorophyll a & b, storage product =
starch, cell wall component: cellulose.
• Ulva (incl. Enteromorpha): bioindicators of
eutrophication (+ importance of correct ID!!)
Chlorophyta: Ulva lactuca, Sea lettuce (Wimereux): 2-layered
membrane, ~ 20 cm large.
Chlorophyta: Ulva (Enteromorpha) intestinalis, Intestine weed
(Wimereux): 30 cm long.
Chlorophyta: massive development of Ulva in the intertidal
(Wimereux) as a result of eutrophication of the coastal water.
Chlorophyta: Cladophora
(Rockweed): habit and detail.
Some species growing in
freshwater.
Chlorophyta: Bryopsis spp.
Chlorophyta (green algae)
•
•
More closely related to higher plants than to the brown or red
algae!!: photosynthesis by chlorophyll a & b, storage product =
starch, cell wall component: cellulose.
Ulva (incl Enteromorpha): bioindicators of eutrophication (+).
• Codium: locally as food.
Chlorophyta: Codium.
Chlorophyta (green algae)
•
•
•
More closely related to higher plants than to the brown or red
algae!!: photosynthesis by chlorophyll a & b, storage product =
starch, cell wall component: cellulose.
Ulva (incl Enteromorpha): bioindicators of eutrophication (+).
Codium: locally as food.
• Halimeda: calcified -> sediments (‘Halimedasand’!! (atolls: up to 90%).
Chlorophyta: Halimeda copiosa
Calcified, segmented thallus
(one segment ~ 0.5 cm).
Chlorophyta: Halimeda tuna (fertile,
with gametangia.
Chlorophyta (green algae)
•
•
•
•
More closely related to higher plants than to the brown or red
algae!!: photosynthesis by chlorophyll a & b, storage product =
starch, cell wall component: cellulose.
Ulva (incl Enteromorpha): bioindicators of eutrophication (+).
Codium: locally as food.
Halimeda: calcified -> sediments!! (atolls: up to 90%)
• Caulerpa: food/toxic; C. taxifolia & C.
racemosa-problem in the Mediterranean Sea.
Chlorophyta: Caulerpa
racemosa var. racemosa:
spherical assimilators.
Chlorophyta: Caulerpa opposita
typespecimen of a new species
but locally extremely abundant.
Phaeophyta (brown algae)
• Photosynthetic pigments: chlorophyll a & c + brown
pigments (xanthophylls); cell wall component:
alginates (see Human uses)!
Phaeophyta (brown algae)
•
Photosynthetic pigments: chlorophyll a & c + brown pigments
(xanthophylls); cell wall component: alginates !
• Mainly cold water (exceptions).
Phaeophyta (brown algae)
•
•
Photosynthetic pigments: chlorophyll a & c + brown pigments
(xanthophylls); cell wall component: alginates !
Mainly cold water (exc.)
• From small and filamentous up to 65 m long; haptera
(root-like) + stipe (stem-like) + lamina (blade-like) +
bladders (floating).
Phaeophyta: Pylaiella littoralis: habit: branched filamentous
(Wimereux): detail of a portion ~ 5 cm long.
Phaeophyta: Laminaria
saccharina, large specimen in
Brittany (Roscoff): ERASMUS
field-course.
Phaeophyta: Laminaria saccharina: haptera, stipes, meristematic
zone (arrows), basis of the blade (Wimereux).
Phaeophyta: Laminaria saccharina: blades with double row of undulations.
Phaeophyta: Fucus vesiculosus, Bladder weed (Wimereux) with
air vesicles (floating).
Phaeophyta (brown algae)
•
•
•
Photosynthetic pigments: chlorophyll a & c + brown pigments
(xanthophylls); cell wall component: alginates !
Mainly cold water (exc.)
From small and filamentous up to 65 m long; haptera (root-like) + stipe
(stem-like) + lamina (blade-like) + bladders (floating).
• Zonation! Adaptation to dessication, salinity and
temperature fluctuations + competition.
Phaeophyta: Pelvetia canaliculata-vegetation in the upper intertidal (Wimereux).
Phaeophyta: Fucus spiralis with numerous receptacles (swollen
reproductive structures) in the high intertidal.
Phaeophyta: Fucus vesiculosus, in the middle intertidal (Wimereux).
Phaeophyta: Ascophyllum
nodosum: replacing Fucus
vesiculosus on sheltered places
(Wimereux).
Phaeophyta: Fucus serratus, low intertidal (Wimereux).
Phaeophyta: Himanthalea
elongata: zone between intertidal
and subtidal (Brittany).
Phaeophyta: Laminaria-zone at spring low tide: Wimereux
(L. saccharina, L. digitata).
Phaeophyta (brown algae)
•
•
•
•
Photosynthetic pigments: chlorophyll a & c + brown pigments
(xanthophylls); cell wall component: alginates !
Mainly cold water (exc.)
From small and filamentous up to 65 m long; haptera (root-like) + stipe
(stem-like) + lamina (blade-like) + bladders (floating).
Zonation! Adaptation to dessication, salinity and temperature fluctuations +
competition.
• Dictyota & Padina frequent in tropics; also Sargassum
ID-problems!! + drifting spp.
Phaeophyta: Dictyota dichotoma.
Phaeophyta: Padina pavonica in situ (Mediterranean Sea).
Phaeophyta: Sargassum muticum
(Japweed) in situ in a low intertidal
rock pool.
Phaeophyta: Sargassum muticum
(Japweed): detail with air bladders
and receptacles (Wimereux).
Rhodophyta (red algae)
• Photosynthetic pigments: chlorophyll a + red and blue
pigments; cell wall component: carrageenans, agar,
chalk (see Human Uses).
Rhodophyta (red algae)
•
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell
wall component: carrageenans, agar, chalk!
• Mainly warm water (exceptions!).
Rhodophyta (red algae)
•
•
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell
wall component: carrageenans, agar, chalk!
Mainly warm water (exceptions!).
• From small and filamentous up to 1 m long;
mostly composed of filaments sticking together by
jelly.
Rhodophyta: Acrochaetium: top left:
tufts of small filaments (~1 cm);
other illustrations: microscopic
details with spore formation.
Rhodophyta: Palmaria palmata, a tough, relatively large (~ 20 cm),
blade-like red alga (Wimereux, subtidal fringe).
Rhodophyta: Batrachospermum: detail of the anatomy: filaments
sticking together by jelly: central axis and whorls of branchlets.
Rhodophyta (red algae)
•
•
•
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell
wall component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of
filaments sticking together by jelly.
• Mostly epilithic, but numerous epiphytic species.
Zonation! Mainly subtidal + intertidal pools
(desiccation).
Rhodophyta: Palmaria palmata (red arrows), in situ, epilithic and
the brown algae Laminaria digitata ( brown arrow) and L.
saccharina (yellow arrow) (Wimereux).
Rhodophyta: Polysiphonia lanosa, epiphytic (hemi-parasitic) on
Ascophyllum nodosum (brown alga) (Wimereux): detail.
Collecting red algae in an
intertidal rock pool (uplift).
Subtidal fringe close to Digue Nord (Boulogne): zone dominated by red algae.
Rhodophyta (red algae)
•
•
•
•
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell wall
component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of filaments
sticking together by jelly.
Mostly epilithic, but numerous epiphytic species. Zonation! Mainly subtidal
+ intertidal pools (desiccation).
• Porphyra (nori): most important sea-vegetable!!
Mariculture. Fundamental research (reproduction)
-> applied research.
-
Rhodophyta: Porphyra purpurea: habit: membranous blade of ~
30 cm long (Wimereux).
The story of Nori and Kathleen Drew
– Traditional: Porphyra growing on Bamboo (Hibi).
• The story of Nori and Kathleen Drew
– discovery of the life cycle: Conchocelis-phase by K. Drew
• triphasic, anisomorphic cycle
• tetraspores (conchospores) grow in oyster shells
• Nori: now a modern industry.
Caulerpa racemosa sold as vegetable in Thailand
Caulerpa racemosa sold as vegetable in Thailand
Rhodophyta (red algae)
•
•
•
•
•
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell
wall component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of
filaments sticking together by jelly.
Mostly epilithic, but numerous epiphytic species. Zonation! Mainly
subtidal + intertidal pools (desiccation).
Porphyra (nori): most important sea-vegetable!! Mariculture.
Fundamental research (reproduction) --> applied research.
• Eucheuma (a.o.) --> carragheenophytes!!
Mariculture.
Rhodophyta: Eucheuma sp. (Tanzania): carragheenophyte.
Rhodophyta: mariculture of Eucheuma in Indonesia: attaching branches
on the ropes; in the background: bags of dried specimens.
Rhodophyta: mariculture of Eucheuma in Indonesia: bamboo
floaters with ropes.
Rhodophyta: mariculture of Eucheuma in Indonesia: ropes with
young attached specimens.
Rhodophyta: mariculture of Eucheuma in Indonesia: underwater
image (seagrasses on the seabottom).
Rhodophyta: mariculture of Eucheuma in Indonesia: fully grown
specimens ready for collecting.
Rhodophyta: mariculture of Eucheuma in Indonesia: collecting the
fully grown specimens in boats.
Rhodophyta: mariculture of Eucheuma in Indonesia: drying in the
sun.
Rhodophyta (red algae)
•
•
•
•
•
•
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell
wall component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of
filaments sticking together by jelly.
Mostly epilithic, but numerous epiphytic species. Zonation! Mainly
subtidal + intertidal pools (desiccation).
Porphyra (nori): most important sea-vegetable!! Mariculture.
Fundamental research (reproduction) --> applied research
Eucheuma (a.o.) --> carragheenophytes!! Mariculture.
• Gelidium: --> agar. Mariculture.
Rhodophyta: Gelidium pulchellum (agarophyte, Brittany).
Rhodophyta (red algae)
•
•
•
•
•
•
•
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell
wall component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of
filaments sticking together by jelly.
Mostly epilithic, but numerous epiphytic species. Zonation! Mainly
subtidal + intertidal pools (desiccation).
Porphyra (nori): most important sea-vegetable!! Mariculture.
Fundamental research (reproduction) --> applied research
Eucheuma (a.o.) --> carragheenophytes!! Mariculture.
Gelidium: --> agar. Mariculture.
• Corallines: "cement in coral reefs"; Med. Sea:
calcified platform; coralligène; maërl (industry -->
destroyed).
Dead coral skeletons, completely overgrown by Corallinaceae (calcified red algae).
The seaward, surf-exposed margin of the reef, cemented by Corallinaceae,
resulting in a pinkish colour.
The seaward, surf-exposed margin of the reef, cemented by Corallinaceae.
Rhodophyta: Corallinales. Encrusting representative:
Phymatolithon lenormandii on rock (Brittany).
Rhodophyta: Corallinales. Pseudolithophyllum expansum (with
epiphytic Halimeda): forming extensive structures at great depth
(>50 m), the “coralligène” (Mediterranean Sea).
Rhodophyta: Corallinales: Lithophyllum tortuosum: forming a ridge (“le
trottoir”) at high tide sea level, especially at surf-exposed sites
(Mediterranean Sea).
Rhodophyta: Corallinales: Lithophyllum tortuosum-"trottoir"
(Mediterranean Sea).
Rhodophyta: Corallinales. Segmented representatives: left:
Corallina officinalis, right: Cheilosporum sagittatum (Australia).
Rhodophyta (red algae)
Some other representatives from the N-French coast
(Wimereux).
Rhodophyta: Gracilaria gracilis: (Wimereux), a carragheenophyte.
Rhodophyta: Chondrus crispus (Irish moss): (Wimereux): carragheenophyte.
Rhodophyta : Plocamium cartilagineum (Wimereux).
Succession; zonation; niche diversity
• Bare surface -> Bacteria -> filamentous algae ->
'fleshy' seaweeds (-> seagrasses).
Succession; zonation; niche diversity
•
Bare surface -> Bacteria -> filamentous algae -> 'fleshy' seaweeds (->
seagrasses).
• Conspicuous zonation (species according climate).
- Intertidal: exposure to air conditions towards high
tide: desiccation, temperature & salinity variations!
- Subtidal: wave action & light (quality and quantity);
down to depth with enough light for photosynthesis.
Dike at Pointe de la Crèche, Boulogne (N France): Verrucaria maura (blackish lichen),
Blidingia minima (light green), Porphyra umbilicalis (brownish purple), Ulva
compressa (dark green), Fucus spiralis (blackish brown), on the bottom: many Ulva.
Zonation in the Mediterranean Sea: intertidal with Rissoella verruculosa,
Lithophyllum tortuosum, Cystoseira mediterranea.
Succession; zonation; niche diversity
•
•
•
Bare surface -> Bacteria -> filamentous algae -> 'fleshy' seaweeds (->
seagrasses).
Conspicuous zonation (species according climate).
Intertidal: exposure to air conditions towards high tide: desiccation,
temperature & salinity variations!
Subtidal: wave action & light (quality and quantity); down to depth with
enough light for photosynthesis
• Geographic distribution: 5 marine phytogeographical
zones (upper and lower boreal, temperate, subtropical
and tropical) defined by critical temperatures:
- min temperature for survival;
- min temperature for repopulation;
- max temperature for repopulation;
- max temperature for survival.
Succession; zonation; niche diversity
•
Bare surface -> Bacteria -> filamentous algae -> 'fleshy' seaweeds (->
seagrasses).
• Conspicuous zonation (species according climate).
• Intertidal: exposure to air conditions towards high tide: desiccation,
temperature & salinity variations!
• Subtidal: wave action & light (quality and quantity); down to depth with
enough light for photosynthesis
• Geographic distribution: 5 marine phytogeographical zones:
- min temperature for survival;
- min temperature for repopulation;
- max temperature for repopulation;
- max temperature for survival.
• Cosmopolitan species (??!! >< molecular data ->
numerous sibling species). Patchiness!! Disjunct
distribution.
Research along the East African coast
New records
update of floristic knowledge
48 species new to Kenya and Tanzania
Example
Dictyota adnata Zanardini
type locality: Irian Jaya (Indonesia)
New: East Africa
Coppejans (1990)
Research Group Phycology, Ghent University
Research along the East African coast
Gibsmithia hawaiiensis
type locality: Hawaii
known from Australië
new: East Africa, South Africa
Seychelles
subtidal
De Clerck et al., Bot. Mar. (subm.)
Research Group Phycology, Ghent University
Research along the East African coast
New species
Vanvoorstia incipiens
intertidal
1 location: Uroa, Zanzibar
De Clerck, Wynnne & Coppejans, Phycologia (1999)
Research Group Phycology, Ghent University
Ecological roles of the seaweed vegetations
• Defining intertidal and subtidal habitats (incl. fauna!)
Ecological roles of the seaweed vegetations
•
Defining intertidal and subtidal habitats (incl. fauna!)
• Large biomass, even in mangroves and
seagrass vegetations -> important role!
Ecological roles of the seaweed vegetations
•
•
Defining intertidal and subtidal habitats (incl. fauna!)
Large biomass, even in mangroves and seagrass vegetations ->
important role!
• Consumption, phycocolloids.
Algal uses and economical potential
• Uses
–
–
–
–
–
food
fertilisers
phycocolloids
fine biochemicals
(fermentation and pyrolysis)
Algal uses and economical potential
• Human food
– 600 BC
• “Some algae are a delicacy fit for the most
honoured guests, even for the King himself”
• 21 species are used in Japan, 10% of the
daily diet
– Nori = Porphyra
– Kombu = Laminaria
– Wakame = Undaria
Algal uses and economical potential
• Human food
– Europe and America
– health food
– traditional foods
» laver bread (Porphyra)
» cheese (Dulse: Palmaria palmatifida)
– dying agents for textiles
– pharmaceuticals (since pre-christian times: ~ officinalis)
Ecological roles of the seaweed vegetations
•
•
•
Defining intertidal and subtidal habitats (incl. fauna!)
Large biomass, even in mangroves and seagrass vegetations ->
important role!
Consumption, phycocolloids.
• Pollution, eutrophication: 'greening of the
coast': Ulva (incl. Enteromorpha).