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.