Red Algae
No flagellated stages
Produce Chlorophyll a & Phycoethrin
Sulfated galactans - gels provide structure but are flexible
-Agar
-Carageenan
Most are filaments
Pseudoparenchymatous growth/construction
Cells lined up in filaments to create frond-like thallus rows of cells hooked together
Filaments have cells joined by pit connections that are plugged with mucous
each cell has own nucleus
Evolution
Parasino - no flagella
Chloro - flagella
Ulca - colonies
Charo - higher plants
Floridian red algae
More complex life cycles
Ex. Gracilaria source of agar - edible
-all are branching filaments or derivatives of branching filaments
Pseudoparenchymatous
Coraline red algae
-encrusting
--from calcium carbonate (mesophyllum mesomorphum)
-calcareus, erect hard strong branches (Amphiroa)
Non-coraline red algae
fleshy, foliose thalli spaghetti noodle like or leafy
Simple filaments
Batrachospermum-fresh water red gunky mess in streams
-with pericentral cells- new growth from apical cell -tufted branches
Polysiphonia = tiers of cells
Encrusting form is made up of many short filaments fused together
Fleshy foliose
Gels give fleshy appearance carageenen and agar multicellular branches
Irish moss(Chondrus) Source of carageenan
Gracilaria agar is over 1/2 weight of algae
Bangean red algae
Simpler less complex life cycles
Important biggest aquaculture product in Porphyra (nori-purple/black sushi wrap)
Reef ridges
Tides and wave break over the reef ridge protecting coral reef
Algal debris makes up reef flat and moves reef further out to ocean
Made up of articulated coraline algae and fleshy foliose algae
Life cycles
Floridian red algae generalized
3 phase life cycle (triphase)
2 diploid stages - 1 gametophyte stage
Gametophytes
Male gametophyte releases spermatids from a spermatangial branch that land on female gametophyte called the carpagonial cell on the carpagonial branch or Trychogyne Then cycstocarps are produced after fertilization (2n) the 2n carpospores are released from the cystocarps to form a tetrasporophyte plant.
n Lambda carrageenan and Kappa carrageenan
The tetrasporophyte plant produces by meiosis 1n tetraspores that reform int to Gametophyte stage.