Interesting facts of seaweeds?

Question

Interesting facts of seaweeds?

Answer 1

They aren't plants, they're protists.

Answer 2

The site below looks like it could help you.

Answer 3

Some taxonomists put them in Protista some put them into their own kingdom Chromista, or colored ones. All algae use chlorophyll a but they vary their accessory pigments. Maximum chlorophyll a depth varies with light penetration or water clarity. Light penetrates down to about 200 meters with enough energy to drive photosynthesis making this the realm phytoplankton occupies. Chlorophyll d, chlorophyll b, chlorophyll c, & carotenoids extend the organisms optical range at depth.

Phytoplankton

http://seagrant.gso.uri.edu/factsheets/p...

The eukaryotic alga in three phylums:

Red Rhodophyta use chlorophylls a and c plus beta-carotene and a number of unique xanthophylls (a subclass of yellow reflecting carotenoids). Carotene gives an orange tinge. Phycoerythrin reflects red light and is therefore responsible for the color of most red algae.

Chlorophyll d is found in some red algae.

http://www.nilauro.com/plocamium/divchar...

http://darter.ocps.net/classroom/klenk/m...

Brown or golden phaeophyta use chlorophyll a & c plus fucoxanthin (the accessory pigment that gives the organism its yellow-brown color) It is another carotenoid.)

Green chlorophyta (chlorophylls a and b) these are most plant like. They use xanthophyll cycle for photoprotection in conjunction with other UV dissipation methods. Some are microphytes, single celled and very simple while others such as Cladophora aerogiphilia, (Marimo balls) would be considered macrophytes. They simply have differing strategies  to grow and persist in the aquatic habitat.

http://www.blackwell-synergy.com/doi/abs...

http://mclibrary.nhmccd.edu/taxonomy/pro...

http://www.ucmp.berkeley.edu/chromista/b...

Algae do not develop from a multicellular embryo into a more complex form like plants.  By simple I mean they develop no specialized tissues that support or transport fluids, they have no roots, stems, or leaves. Their cell wall chemistry contains components like agar or alginic acids mixed with cellulose. They do have plastids and chlorophyll but they contain pyrenoids to fix CO2 into starch. Their plastids are less specialized in their functions. The plastids such as amyloplasts to store starch and chloroplasts that just photosynthesize are found in plants not algae.