Botany 10 - Red Algae

Terms	Definitions
Fossil Rhodophyta	Bangia 1200 my old!
Rhodophyta Characteristics	No flagella Multinucleated cells (from multiplication of nuclei in single cell, migration of nuclei into cell, or fusions between cells) -retain phycobilins -most are multicellular, marine, benthic, seaweeds -have pit plug between cells -can be blue, green, yellow, black
Pit connection	Found in most red algae, nothe else: Cytokinesis is incomplete, leaving hole in cell wall that is filled with protein/polysaccharides
Rhodophyta plastids	primary endosymbiosis of eukaryotic cell with cyanobacteria two membranes; single thylakoids Chl a; phycocyanin, phycoerythrin, etc - thallus can be blue, green, yellow, black, etc. pyrenoids rare alpha-linked polyglucan (Floridiean starch) stored outside chloroplast Note: this plastid is also the source of plastids for secondary endosymbiosis in other lineages (stramenopiles, cryptomonads, alveolates, haptophytes)
Rhodophyta sexual reproduction	- asexual reproduction common - 2-phase iso- or heteromorphic - carposporophytes (zygote froms vegetative tissue that consed the zygote via carpospores - like Brave New World) -oogamous (male gametes = spermatia; female gametes =carpogonia) - sporophyte (tetrasporophyte) produces sets of 4 spores via meiosis (tetraspores) http://www.scielo.br/scielo.php?script=sci_arttext&pid=s1415-47571999000100020&lng=pt&nrm=iso
Carposporophytes	Life history form in red algae vegetative tissue formed by zygote produces carpospores (clones of the zygote) increases liklihood of successful dispersal http://www.botany.hawaii.edu/faculty/webb/bot311/rhodophyta/PolysiphoniaCarpoSporangiaClosedCropLab250.jpg
Carpogonia	Female gamete in red algae
Spermatia	Male gamete in red algae
Tetrasporophyte	Sporophyte in red algae Produces spores via meiosis in groups of 4 (each is a tetraspore)
Tetraspore	One of the four products of meiosis produced by the red algal tetrasporophyte
Bangiales	Order of Rhodophyta (Red Algae) •Life history: 2-phase heteromorphic •Thalli: bladelike or tubular: gametophyte large, lacks pit connections; sporophytes shell boring Example: Porphyra (laver)
Gelidiales	Oder of Rhodophyta (Red Algae) •Life history: Isomorphic life history •Thalli - wiry, unbranched •Reproduction: asexual reproduction predominant •Example: Gelidium (principle source of agar)
Gracilariales	Order of Rhodophyta (Red Algae) •Life history: Isomorphic •Thalli: fleshy, branched uniaxial •asexual reproduction by fragmentation predominant •Example: Gracilaria, a source of agar
Palmariales	Order of Rhodophyta (Red Algae) •Life history: Heteromorphic life history (male gametophytes macroscopic; female gametophytes microscopic; no carposporophyte) •Thalli: Multiaxial with blades or tubes •Example: Palmaria (Edible seaweed, dulse), Halosaccion
Coralliniales	Order of Rhodophyta (Red Algae) •Life history: Isomorphic •Thalli: Erect or crustose; jointed or not; erect can have crustose base; Calcified •Reproduction: Reproductive structures in conceptacles •Examples: Bossiella, Corallina. Calliarthron note - signficant fossil records
Gigartinales	Order of Rhodophyta (Red Algae) •Life history: Isomorphic or heteromorphic (heteromorphic - gametophyte larger) •Thalli: Erect or crustose •Example: Mazzaella (source of carrageenan); Mastocarpus (heteromorphic); Chondracanthus (isomorphic)
Ceramiales	Order of Rhodophyta (Red Algae) •Life history: Isomorphic; (carphosporophyte auxillary cell formed after fertilization) •Thalli: filamentous or uniaxial blades; +/- cortex/medulla •Example: Polysiphonous red algae