Coccolithophore: Difference between revisions

| fossil_range = {{fossilrange|Rhaetian|Recent}}

| image = Coccolithus pelagicus.jpg

| domain = [[Eukaryota]]

| unranked_superregnum = [[Diaphoretickes]]

Silicate- or cellulose-armored functional groups such as [[diatom]]s and [[dinoflagellate]]s do not need to sustain the calcification-related H+ efflux. Thus, they probably do not need to adapt in order to keep costs for the production of structural elements low. On the contrary, dinoflagellates (except for calcifying species;<ref>{{cite journal |doi = 10.1371/journal.pone.0065987|title = Ocean Acidification Reduces Growth and Calcification in a Marine Dinoflagellate|year = 2013|last1 = Van De Waal|first1 = Dedmer B.|last2 = John|first2 = Uwe|last3 = Ziveri|first3 = Patrizia|last4 = Reichart|first4 = Gert-Jan|last5 = Hoins|first5 = Mirja|last6 = Sluijs|first6 = Appy|last7 = Rost|first7 = Björn|journal = PLOS ONE|volume = 8|issue = 6|pages = e65987|pmid = 23776586|pmc = 3679017|bibcode = 2013PLoSO...865987V| doi-access=free }}</ref> with generally inefficient CO₂-fixing [[RuBisCO|RuBisCO enzymes]]{{hsp}}<ref>{{cite journal |doi = 10.4319/lo.2000.45.3.0744|title = Evolutionary and ecological perspectives on carbon acquisition in phytoplankton|year = 2000|last1 = Tortell|first1 = Philippe D.|journal = Limnology and Oceanography|volume = 45|issue = 3|pages = 744–750|bibcode = 2000LimOc..45..744T|doi-access = free}}</ref> may even profit from chemical changes since photosynthetic [[carbon fixation]] as their source of structural elements in the form of cellulose should be facilitated by the ocean acidification-associated CO₂ fertilization.<ref>{{cite journal |doi = 10.1016/j.hal.2007.05.006|title = A comparison of future increased CO2 and temperature effects on sympatric Heterosigma akashiwo and Prorocentrum minimum|year = 2008|last1 = Fu|first1 = Fei-Xue|last2 = Zhang|first2 = Yaohong|last3 = Warner|first3 = Mark E.|last4 = Feng|first4 = Yuanyuan|last5 = Sun|first5 = Jun|last6 = Hutchins|first6 = David A.|journal = Harmful Algae|volume = 7|pages = 76–90}}</ref><ref>{{cite journal |doi = 10.1146/annurev-marine-120709-142720|title = Carbon Concentrating Mechanisms in Eukaryotic Marine Phytoplankton|year = 2011|last1 = Reinfelder|first1 = John R.|journal = Annual Review of Marine Science|volume = 3|pages = 291–315|pmid = 21329207|bibcode = 2011ARMS....3..291R}}</ref> Under the assumption that any form of shell/exoskeleton protects phytoplankton against predation{{hsp}}<ref name="Evolution of Primary Producers in t"/> non-calcareous armors may be the preferable solution to realize protection in a future ocean.<ref name=Bach2015 />

 

 

The diagram on the right is a representation of how the comparative energetic effort for armor construction in diatoms, dinoflagellates and coccolithophores appear to operate. The [[frustule]] (diatom shell) seems to be the most inexpensive armor under all circumstances because diatoms typically outcompete all other groups when silicate is available. The coccosphere is relatively inexpensive under sufficient [CO₂], high [HCO₃−], and low [H+] because the substrate is saturating and protons are easily released into seawater.<ref name="A Voltage-Gated H+ Channel Underlyi"/> In contrast, the construction of [[Dinoflagellate#Morphology|thecal]] elements, which are organic ([[cellulose]]) plates that constitute the dinoflagellate shell, should rather be favored at high H+ concentrations because these usually coincide with high [CO₂]. Under these conditions dinoflagellates could down-regulate the energy-consuming operation of carbon concentrating mechanisms to fuel the production of organic source material for their shell. Therefore, a shift in carbonate chemistry conditions toward high [CO₂] may promote their competitiveness relative to coccolithophores. However, such a hypothetical gain in competitiveness due to altered carbonate chemistry conditions would not automatically lead to dinoflagellate dominance because a huge number of factors other than carbonate chemistry have an influence on species composition as well.<ref name=Bach2015>{{cite journal |doi = 10.1016/j.pocean.2015.04.012|title = A unifying concept of coccolithophore sensitivity to changing carbonate chemistry embedded in an ecological framework|year = 2015|last1 = Bach|first1 = Lennart Thomas|last2 = Riebesell|first2 = Ulf|last3 = Gutowska|first3 = Magdalena A.|last4 = Federwisch|first4 = Luisa|last5 = Schulz|first5 = Kai Georg|journal = Progress in Oceanography|volume = 135|pages = 125–138|bibcode = 2015PrOce.135..125B|doi-access = free}} [[File:CC-BY icon.svg|50px]] Material was copied from this source, which is available under a [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International License].</ref>