Write a note on Rhodophyceae.

(N/A) $\rightarrow$ The members of Rhodophyceae are commonly called red algae because of the predominance of the red pigment,$r$-phycoerythrin in their body.
$\rightarrow$ Habitat: Majority of the red algae are marine with greater concentrations found in warmer areas.
$\rightarrow$ They occur in both well-lighted regions close to the surface of water and also at great depths in oceans where relatively little light penetrates.
$\rightarrow$ Body structure: The red thalli of most of the red algae are multicellular. Some of them have complex body organisation.
$\rightarrow$ Stored food: The food is stored as floridean starch which is very similar to amylopectin and glycogen in structure.
$\rightarrow$ Reproduction:
$\rightarrow$ Vegetative reproduction: The red algae usually reproduce vegetatively by fragmentation.
$\rightarrow$ Asexual reproduction: They reproduce asexually by non-motile spores.
$\rightarrow$ Sexual reproduction: The red algae usually reproduce by gametes. Sexual reproduction is oogamous and accompanied by complex post-fertilisation developments.
$\rightarrow$ Common members are $Polysiphonia$,$Porphyra$,$Gracilaria$ and $Gelidium$.