AqBot Exam 3: Lecture 17

what are 3 types of macroalgae?

Rhodophyta, Chlorophyta, and Phaeophyceae (Ochrophyta)

define thallus

entire body of macroalgae

define uniseriate vs. multiseriate

uniseriate is single row of cells and multiseriate is multiple rows of cells

define siphonocladous

multiple cells with multiple nuclei in cells

define siphonous

one drawn out (tubular) cell w/ thousands-millions of nuclei

define siphonous macronucleate

one drawn out (tubular) cell with one macronuclei

define parenchyma

tissue formed by division in 3 planes

define pseudoparenchyma

filaments bundled together which resemble parenchyma

what are some characteristics of Rhodophyta?

• calcified

• tolerates acid conditions

• no flagella

• Floridean starch = storage product/food reserve

• chloroplast

  • 2 membranes

  • chlorophyll a pigment

  • phycobiliproteins

  • complementary chromatic adaptation

  • unstaked thylakoids

how many Rhodophyta spp?

what is a primitive order?

what are the 3 more advanced orders

• 5200 spp

• primitive = Bangiales

• advanced = Corallinales, Gracilariales, and Ceramiales

Order: Bagiales

• habitat

• spp

• epiphytic and intertidal spp, some occur in FW

• Porphyra perforata

Order: Bagiales

Porphyra perforata

• habitat

• what occurs in this spp. during low tide

• use

• physical characteristic

• intertidal spp.

• at low tide extreme desiccation occurs, plant loses 90% of fresh weight, and reduction in photosynthesis occurs

• food source in many cultures especially in sushi

• has a variable colors => more red is more submerged while intertidal spp are brown and green

Order Corallinales

• characteristics

• habitat

• VERY calcified red algae that grows in crustose or nodular forms; articulated or jointed forms/segments

• reef-building algae so epiphytic and can grow 125m in The Bahamas

what are the 2 forms of calcification for Corallinales?

what determines rate of calcification?

• calcite and aragonite

• calcification occurs more rapidly in light

Order Gracilariales

• physical characteristics

• habitat

• important symbiotic relationship

• fleshy growth form, may be flattened or foliose/leaf-like

• widely distributed, farmed in brackish water ponds, present in PCOLA/GoM

• used in farmed brackish water ponds for abalone culture => abalone feeds on Gracilaria while the algae feeds on fecal matter of abalone

Order Ceramiales

• physical appearance

• habitat

• 2 spp.

• delicate filamentous or membranous forms => resembles a clump of hair

• attaches to soft and hard structures; found in PCOLA

• Polysiphonia and Ceramium

Order Ceramiales

Polysiphonia

• habitat

• relationship w/ damselfish

• may be epiphytic or colonize solid surfaces

• damselfish plant parts of the algae for cultivation to use as a food source

Order Ceramiales

Ceramium

• habitat

very common worldwide

lives in estuaries and intertidal-subtidal marine environments

lives on variety of substrates

• what is a major product of photosynthesis in Rhodophyta?

• what is its importance?

• how is it stored?

• what are some secondary products of photosynthesis?

• floridoside (equivalent to sucrose in green algae/plants)

• important for osmoregulation to balance salt ratio to water in spp.

• transformed in Floridean starch for long term storage

• manitol, sorbitol, digeneaside, dulcitol (alcohols)

how is Rhodophyta commercially used?

agar and carageenan in food

Phylum Rhodophyta

Class Ulvophyceae

• habitat

• characteristics

• 3 orders

• marine but some FW

• single celled and large filamentous green algae/seaweeds

• Ulvales (sea lettuce), Cladophorales, Caulerpales

Phylum Rhodophyta

Class Ulvophyceae

Order Ulvales

• describe thallus

• symbiosis

• define Ulva

• thallus has fronds in sheet-like or hollow cylinder form

  • monostroma = one cell thick

  • ulva = two cells thick

• algae pairs w/ bacteria in which the bacteria releases thallusin when algae is attached and signals for the algae to start growing

• ulva = chloroplast near exterior of cell, holdfast formed from filaments

Phylum Rhodophyta

Class Ulvophyceae

Order Cladophorales

• describe growth form

• describe cells

• describe chloroplast

• 2 genera

• filamentous, branched or unbranched

• multinucleate cells

• chloroplast is either parietal or reticulate

  • pyrenoids occur at intersections of reticulate chloroplasts

• Cladophora and Chaetomorpha

Phylum Rhodophyta

Class Ulvophyceae

Order Cladophorales

• describe problem in Great Lakes

• large blooms in 50s

• caused by abundance of hard substrate, water temp 10-25C, light availability, and lots of nutrients/phosphorus

• sensence occurs during midsummer/fall in which macroalgae die and form drifts

• P control was implemented to limit algae growth

• due to invasize zebra mussels, water clarity increased so algae could grow deeper

Phylum Rhodophyta

Class Ulvophyceae

Order Cladophorales

Cladophora sericea

• habitat

• unique capability that increases its longevity

• problem it caused

• small part of biomass in intertidal community; attached to solid substrate

• nitrate storage ability increases its longevity in stressful conditions

• invasive in Hawaii of leeward reefs in large masses drifted in the water column and would snag onto corals which they smothered

Phylum Rhodophyta

Class Ulvophyceae

Order Caulerpales

• habitat

• characteristics

• 2 families

• marine

• multinucleate w/out cross walls; coenocytic or siphonoaceous

• Codiaceae and Caulerpacea

define coenocytic

single, continuous, multinucleate protoplasm encased by cell wall

Phylum Rhodophyta

Class Ulvophyceae

Order Caulerpales

• what is unique about growth rates?

• affect of gravity

• repairing ability

• growth rate is constant for all “tissues”

• gravity affects distribution of amyloplasts

  • high conc. of amyloplasts = rhizoid develops (anchoring)

  • low conc. of amyloplasts = frond develops (above ground biomass)

• when thallus is damaged, caulperin releases oxytoxin 2 allowing cytoplasmic proteins to form plugs quickly to continue growth

Phylum Rhodophyta

Class Ulvophyceae

Order Caulerpales

• problem of killer algae

accidentally released from aquariums that covered Med. sea and is now spreading worldwide

Phylum Rhodophyta

Class Ulvophyceae

Order Caulerpales

Family Codiacea

• importance of family

• 2 genus

• important reef building family

• Halimeda and Codium

Phylum Rhodophyta

Class Ulvophyceae

Order Caulerpales

Family Codiacea

Genus Halimeda

• describe where it can calcify

• describe rate of calcification

• can calcify in many environments and can grow 1 segment a day

  • new segments are white and uncalcified

  • old segments green and calcified

• calcification is greater the day in which 1) chloroplasts move toward edge of segments, 2) ions bind to wall, 3) CaCO3 precipitates

Phylum Rhodophyta

Class Ulvophyceae

Order Caulerpales

Family Codiacea

Genus Codium

• habitat

• morphology

• sp.

• tropical and temperate ocean

• morphology

  • filamentous thallus

  • dichotomously branch shoots

  • central core = colorless filament

  • utricles = inflated branchlets surrouding core

  • small nuclei in interior of cytoplasm

• Codium fragile

Phylum Rhodophyta

Class Ulvophyceae

Order Caulerpales

Family Codiacea

Genus Codium

Codium fragile

• habitat

• tolerations

• what happens during winter

• what happends during summer

• subtidal-70m; attaches to oysters and shellfish

• tolerates wide temp and salinity, undergoes N-fixation w/ Azotobacter

• winter is stores N and undergoes high C-fixation, high pigment content, and chloroplast size

• reproduction during summer months