''Triparma'' is a genus of unicellular algae in the family Triparmaceae in the order

Parmales The Parmales are an order of marine microalgae within the Bolidophyceae class. They are found worldwide and characterized by a cell wall composed of 5-8 interlocking silica plates with distinct forms. They were initially thought to be loricate ch ...

. They form siliceous plates on the cell surface that aid in identification. ''Triparma'' is distinguished by its possession of three shield plates, three triradiate girdle plates, a triradiate girdle plate with notched ends, and a small ventral plate. It was first described by Booth & Marchant in 1987 and the holotype is ''Triparma columacea''. ''Triparma'' cells have two forms: the motile, naked form and the non-motile siliceous form. The motile cells propelled by two flagella of unequal length, typical of

heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line of eukaryotes. Most are algae, ranging from the giant multicellular kelp to the unicellular diatoms, which a ...

s. The non-motile forms do not possess flagella but instead have a silicified cell wall with a distinctive plate morphology: three shield plates, three oblong girdle plates, a triradiate dorsal plate with rounded ends, and a large ventral plate. Both forms contain a single, dorsal chloroplast that contains

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to ...

s ''a'' and ''c_1-3'' as well as fucoxanthin. They are typically 1-2 μm in size and generally spherical or heart-shaped. The genus ''Triparma'' is actively studied because of their close relationship to the diatoms, and it has been discovered that they have different silica-limitation responses. While diatoms stop growing and cell division is inhibited under low-silica conditions, ''Triparma'' continues to grow and divide normally even under nanomolar concentrations of silica, although the silica plates are no longer produced.

Photosynthetic pigments A photosynthetic pigment (accessory pigment; chloroplast pigment; antenna pigment) is a pigment that is present in chloroplasts or photosynthetic bacteria and captures the light energy necessary for photosynthesis. List of photosynthetic pigme ...

present in bolydophyte chloroplasts include

s a, c₁, c₂, c₃, fucoxanthin,

diatoxanthin Diatoxanthin is a type of xanthophyll found in phytoplankton and diatom A diatom ( Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, ...

, diadinoxanthin.

Synonyms

The genus now includes all species from the non-monophyletic genus ''Bolidomonas'', according to Ichinomiya ''et al'' (2016).

Taxonomy

* Class

Bolidophyceae Bolidophyceae is a class of photosynthetic heterokont picophytoplankton, and consist of less than 20 known species. They are distinguished by the angle of flagellar insertion and swimming patterns as well as recent molecular analyses. Bolidophyc ...

Guillou & Chretiennot-Dinet 1999 ** Order

Booth & Marchant 1987 *** Family Triparmaceae Booth & Marchant 1988 **** Genus ''Triparma'' Booth & Marchant 1987 ***** Species '' T. columacea'' Booth 1987 ***** Species '' T. eleuthera'' Ichinomiya & Lopes dos Santos 2016 ***** Species '' T. laevis'' Booth 1987 ***** Species '' T. mediterranea'' (Guillou & Chrétiennot-Dinet) Ichinomiya & Lopes dos Santos 2016 ***** Species '' T. pacifica'' (Guillou & Chrétiennot-Dinet) Ichinomiya & Lopes dos Santos 2016 ***** Species '' T. retinervis'' Booth 1987 ***** Species '' T. strigata'' Booth 1987 ***** Species '' T. verrucosa'' Booth 1987

References

{{Taxonbar, from=Q21227150 Algae genera Heterokont genera Ochrophyta