Cryptophyceae

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Cryptophyta
)

Cryptophytes
Rhodomonas salina
Eukaryota
)
Domain:
Eukaryota
(unranked):
Cryptista
Superclass:
Cryptomonada
Class:
Cryptophyceae
Orders
Synonyms
  • Cryptomonada Senn 1900
  • Cryptomonadinae Pascher 1913
  • Cryptomonadophyceae Pascher ex Schoenichem 1925

The cryptophyceae are a class of

10–50 μm in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella
.

Some exhibit

mixotrophy.[3]

Characteristics

flagella, 11-invagination, 12-lipid globules, 13-ejectosomes, 14-mitochondrion, 15-pyrenoid, 16-Golgi apparatus, 17-endoplasmic reticulum, 18-chloroplast-endoplasmic reticulum
.

Cryptophytes are distinguished by the presence of characteristic extrusomes called ejectosomes or ejectisomes, which consist of two connected spiral ribbons held under tension.[4] If the cells are irritated either by mechanical, chemical or light stress, they discharge, propelling the cell in a zig-zag course away from the disturbance. Large ejectosomes, visible under the light microscope, are associated with the pocket; smaller ones occur underneath the periplast, the cryptophyte-specific cell surrounding.[5][6]

Except for

red alga.[7] However, the plastids are very different from red algal plastids: phycobiliproteins are present but only in the thylakoid lumen and are present only as phycoerythrin or phycocyanin. In the case of "Rhodomonas" the crystal structure has been determined to 1.63Å;[8]
and it has been shown that the alpha subunit bears no relation to any other known phycobiliprotein.

A few cryptophytes, such as

mastigonemes, formed within the endoplasmic reticulum and transported to the cell surface. Small scales may also be present on the flagella and cell body. The mitochondria have flat cristae, and mitosis is open; sexual reproduction
has also been reported.

The group have evolved a whole range of light-absorbing pigments, called phycobilins, which are able to absorb wavelengths that are not accessible to other plants or algae, allowing them to live in a variety of different ecological niches.[9] An ability that originates from the evolution of a unique light‐harvesting antenna complex derived from two relict parts of the red algal phycobilisome, which was completely dismantled during the endosymbiotic process.[10]

While cryptophytes are usually seen as asexual, sexual reproductions do occur; both haploid and diploid forms have been found. The two species Teleaulax amphioxeia and Plagioselmis prolonga are now considered to be the same species, where T. amphioxeia is the diploid form and P. prolonga is the haploid form. The diploid form is most common when there are more nutrients in the water. Two haploid cells will often fuse to form a diploid cell, mixing their genes.[11]

Classification

Cryptophytes under SEM
light microscope
Further information: Wikispecies:Cryptophyceae

The first mention of cryptophytes appears to have been made by

Haptophyta the group Hacrobia. Parfrey et al. and Burki et al. placed Cryptophyceae as a sister clade to the Green Algae.[13][14]

One suggested grouping is as follows: (1)

Falcomonas daucoides.[15]

References

  1. PMID 18397952
    .
  2. ^ Cryptophyceae - :: Algaebase
  3. ^ "Cryptophyta - the cryptomonads". Archived from the original on 2011-06-10. Retrieved 2009-06-02.
  4. ISBN 9780321559654
    .
  5. PMID 6155157
    .
  6. PMID 6470985
    .
  7. PMID 11323671
    .
  8. PMID 10430868
    .
  9. ^ Callier, Viviane (23 October 2019). "This Type of Algae Absorbs More Light for Photosynthesis Than Other Plants". Smithsonian Magazine.
  10. ^ Molecular structures reveal the origin of spectral variation in cryptophyte light harvesting antenna proteins
  11. ^ Dimorphism in cryptophytes—The case of Teleaulax amphioxeia/Plagioselmis prolonga and its ecological implications
  12. ^ Novarino, G. (2012). "Cryptomonad taxonomy in the 21st century: The first 200 years". Phycological Reports: Current Advances in Algal Taxonomy and Its Applications: Phylogenetic, Ecological and Applied Perspective: 19–52. Retrieved 2018-10-16.
  13. PMID 21810989
    .
  14. PMID 26817772
    .
  15. ^ "Cryptomonads". Retrieved 2009-06-24.
  16. S2CID 51718360. Archived from the original
    (PDF) on 2018-10-12. Retrieved 2019-05-26.

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Cryptophyceae&oldid=1202638006"