Phytoplankton taxonomy and evolution Flashcards
Prymnesiophytes
Coccolithophores.
aka Haptophytes. Unicellular photosynthetic flagellates. Heterotrophic taxa re unknown in this clade!
Cryptophyta
Class of green algae. 10–50 μm in size and flattened in shape, two flagella.
Pelagophyta
referred to earlier as chrysophytes but is now its own Class. nearly all chrysophytes become facultatively heterotrophic in the absence of adequate light, or in the presence of plentiful dissolved food. Contain chlorophyl BUT also have a carotenoid pigment called fucoxanthin (gives them yellow-brown color). Classification: Chromalveolata
Pyrrophyta
Includes dinoflagellates, most = marine. Cellulose and 2 flagella. Store E as starch. Contain fucoxanthin
Chlorophyta
Division classification. Green algae. E.g., Ulva lactuca sea lettuce and Class prasinophytes e.g., Ostreococcus. And the Order Chlorella.
Rhodophyta
Division classification. Red algae. Most diverse in tropics. E.g., Irish moss, porolithon
Prasinophyta
Class within the Divison Chlorophyta. E.g., Ostreococcus and Micromonas
Alveolata
“superphylum”. group of protists. Contains dinoflagellates and also plasmodium. Also ciliates.
Stramenopila
aka heterokont. Phylum. group of protists. 100,000 known species. includes diatoms (bacillariophyta) and chrysophytes (golden algae) and phaeophytes (brown algae e.g. kelp)
Rhodophyta
Division. Red algae. Group of protists. multicellular, lack flagella, reproduce sexually. One of the oldest fossils IDed as red algae is also the oldest fossil eukaryote belonging to an extant taxon.
Protists aka protozoa
Paraphyletic group of eukaryotes, contains some heterotrophs, mixotrophs, autotrophs. Alveolata, Stremopila, Many have flagella and cilia, extensions of cytoplast (in contrast to prokaryotes where its attached to the cell surface).
Alveolates
Dinoflagellates
Photosynthesis evolved
2.7 billion years ago (Ga)
Photosynthetic eukaryotes evolved
1.5 billion years ago (Proterozoic era)
Red algae evolve, leading to endosymbiosis - plastids derived from an ancestral red algae by secondary symbiosis
1.2 billion years (Ga).
Coccoliths rise to dominance
90 million years - the Cenomanian/Turonian boundary, about 90 million years before present [Iglesias-Rodriguez et al., 2002]. Sarmiento: “it is interesting to note that most of the organisms that precipitate CaCO3 in today’s open oceans are relatively young from an evolutionary perspective” (textbook, p363)
Bolide impact in the Cretacious/Tertiary boundary and effects
65 million years ago - removed a major portion of phyto diversity, partic among cocoliths
diversities of of dinoflagellates and cocoliths recovered, diatoms radiate
55 mya - early Eocene
smallest free living eukaryote
ostreococcus
ref: class
Haptophytes
Phylum, aka Prymnesiophytes, containing coccolithophores in the kingdom Chromalveolata. Contains 5 orders, with one of them being coccolithophores
Source: wiki
Chromalveolate hypothesis
chlorophyll c- containing plastids originated from a single photosynthetic ancestor, which obtained plastids once once by secondary endosymbiosis with red algae (Cavalier Smith 2002, Keeling 2009, 2010). However, phylogenetic studies suggest higher incidence of secondary endosymbiotic events/ plastid transfer. Single “monophyly” of Cryptophytes, Alveolates, Stramenopiles, and Haptophytes is not supported by reent mitochondrial or nuclear sequence data despite all having chloroplasts (Ref: Genomics of Chloroplasts and Mitochondria, Ralph Bock, Volker Knoop)