Pachycladella

{{Short description|Genus of algae}} {{Automatic taxobox | image = Pachycladella cf. zatoriensis 1.jpg | image_caption = ''Pachycladella'' cf. ''zatoriensis'' | taxon = Pachycladella | authority = P.C.Silva, 1970 | type_species = ''Pachycladella umbrina'' | type_species_authority = (G.M.Smith) P.C.Silva<ref name=AlgaeBase/> | subdivision_ranks = Species | subdivision = * ''Pachycladella komarekii'' * ''Pachycladella minor'' * ''Pachycladella umbrina'' * ''Pachycladella zatoriensis'' }}

'''''Pachycladella''''' is a genus of green algae in the family Oocystaceae. It occurs in freshwater habitats and has a cosmopolitan distribution, but is rare.<ref name=AlgaeBase>{{AlgaeBase genus|name=Pachycladella|id=44572}}</ref>

==Taxonomy== ''Pachycladella'' was first described by Gilbert Morgan Smith in 1924, under the name ''Pachycladon''; the name was illegitimate as it was a junior homonym of ''Pachycladon'', a genus in the family Brassicaceae. A replacement name, ''Pachycladella'' was coined by Paul Silva in 1970.<ref name=Bicudo_and_Menezes2006>{{cite book | title= Gêneros de Algas de Águas Continentais do Brasil: chave para identificação e descrições | edition=2 | year=2006 | first1=Carlos E. M. |last1=Bicudo | first2=Mariângela | last2= Menezes | publisher= RiMa Editora | pages=508 | isbn= 857656064X }}</ref>

The type species of the genus, ''Pachycladella umbrina'', has also been placed in the genus ''Treubaria'', although this transfer is not agreed upon by all taxonomists.<ref>{{Cite journal | title = Notes on two green plankton found in Bangladesh | year = 2005 | journal = Bangladesh Journal of Plant Taxonomy | pages = 97–99 | volume = 12 | issue = 2 | last1 = Nurl Islam | first1 = A.K.M. | last2 = Almujaddade Alfasane | first2 = Md }}</ref>

==Description== ''Pachycladella'' consists of single, microscopic cells. Cells are mostly spherical to quadrangular or lobate, 3–13 μm in diameter, with four extensions (termed processes) arranged in a cruciate or tetrahedral fashion. The processes are tubular or conical, of equal length, up to 120 μm long and up to 4 μm wide at the base; the apex may be blunt-tipped or bifurcate apex. Processes are translucent to dark brown and structurally different from the cell wall. Cells are uninucleate (with one nucleus) and have one cup-shaped, parietal chloroplast with a single pyrenoid.<ref name=AlgaeBase/>

Asexual reproduction occurs by the formation of zoospores with two flagella. The flagellar basal bodies are arranged in a clockwise orientation. Sexual reproduction is unknown.<ref name=AlgaeBase/>

Species are distinguished based on morphological characteristics, such as the size of the cells and arrangement of processes. However, the species are poorly studied and thus the species boundaries are in need of revision.<ref>{{cite journal|doi=10.3897/phytokeys.56.6268|doi-access=free |title=A new record of the rare alga ''Pachycladella'' P. C. Silva (Chlorophyceae) in New England |date=2015 |last1=Fucikova |first1=Karolina |journal=PhytoKeys |issue=56 |pages=19–27 |pmid=26491383 |pmc=4611745 }}</ref>

==References== {{Reflist|1}}

Category:Trebouxiophyceae genera Category:Freshwater algae Category:Oocystaceae