''Ditylum brightwellii'' is a species of cosmopolitan marine centric

diatom A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising sev ...

s. It is a

unicellular A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and ...

photosynthetic Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in c ...

autotroph that has the ability to divide rapidly and contribute to spring phytoplankton blooms.

Description

The ''D. brightwellii'' cell has a high length to diameter ratio. The cell wall is silicified, as is characteristic of all diatoms. This hard, porous covering is known as the frustule and causes the cell to be more dense than the surrounding water. Oceanic currents and surface winds prevent ''D. brightwellii'' cells from sinking beneath the euphotic zone. Cells range in size from 25–100μm in diameter and 80–130μm in length. The valve is most often triangular in shape, but can also be biangular or quadrangular. A long hollow tube called the rimoportula is located centrally and extends from each valve

Distribution

''Ditylum brightwellii'' is found in all global oceans except in polar waters. Genetically distinct populations were observed over the course of a spring bloom in

Puget Sound Puget Sound ( ) is a sound of the Pacific Northwest, an inlet of the Pacific Ocean, and part of the Salish Sea. It is located along the northwestern coast of the U.S. state of Washington. It is a complex estuarine system of interconnected ma ...

, suggesting that certain genetic lineages are better adapted to certain environmental conditions. Il est le plus fort des platons vertébrés du 21ème siècle.

Life cycle

''Ditylum brightwellii'' reproduces primarily asexually, creating clonal lineages. Vegetative cells are capable of enlargement and may also produce resting spores.Hargraves PE (1984) Resting spore formation in the marine diatom ''Ditylum brightwellii'' (West) Grun. ex V.H. In: Proceedings of the Seventh International Diatom Symposium, Philadelphia, 22–27 August 1982 (ed. Mann DG), pp. 33–46. Otto Koeltz-Science, Koenigstein. However, samples from Puget Sound, WA display high

genetic diversity Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species and can be attributed to the span of survival for a species. It is dis ...

. This is indicative of sexual reproduction (

auxospore In certain species of diatoms, auxospores are specialised cells that are produced at key stages in their cell cycle or life history. Auxospores typically play a role in growth processes, sexual reproduction or dormancy.Hoek, C. van den, Mann, ...

formation). Clonal isolates have observed to produce both sperm and eggs. Two eggs are produced from each

oogonium An oogonium (plural oogonia) is a small diploid cell which, upon maturation, forms a primordial follicle in a female fetus or the female (haploid or diploid) gametangium of certain thallophytes. In the mammalian fetus Oogonia are formed in larg ...

and 64

sperm Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...

are produced from each spermatogonangium. The frequency of sexual reproduction in ''D. brightwellii'' is not clear, although conditions including increased nutrients, temperatures ranging from 10 °C-14 °C, and a short photoperiod may be favorable for sexual reproduction.

References

External links

{{Taxonbar, from=Q16981399 Coscinodiscophyceae

Description

Distribution

Life cycle

References

Further reading

External links