Navicula

Navicula
	Navicula reinhardtii
Scientific classification
Domain:	Eukaryota
Clade:	Diaphoretickes
Clade:	SAR
Clade:	Stramenopiles
Phylum:	Gyrista
Subphylum:	Ochrophytina
Class:	Bacillariophyceae
Order:	Naviculales
Family:	Naviculaceae
Genus:	Navicula; Bory de Saint-Vincent, 1822
Type species
	Navicula tripunctata;
Species
	List of Navicula species;

Navicula is a genus of boat-shaped diatom (single-celled photosynthetic organisms), comprising over 1,200 species,^[1] though many Navicula species likely do not belong in the genus strictly speaking.^[2] Navicula is Latin for "small ship", and also a term in English for a boat-shaped incense-holder.^[2] Navicula is a cosmopolitan genus and species are present in both freshwater and marine environments, typically attached to surfaces (i.e. benthic).

Description

Navicula species are pennate diatoms. Their valves are typically elliptical, though some species have more pinched ends than others. Navicula cells have two chloroplasts, one along each side of the valve along the girdle bands.

Mobility

Navicula diatoms are highly motile and move through a gliding movement^[3]^[4]^[5] This is done through excretion of extracellular polymeric substances (EPS). One form of EPS surrounds the outside of the cell and another is excreted through a slit in the frustule called a raphe, allowing the cell to glide along a track.^[6]

References

^ M.D. Guiry (2015). Guiry, M.D.; Guiry, G.M. (eds.). "AlgaeBase". World-wide electronic publication, National University of Ireland, Galway. Retrieved 2015-08-15.
^ ^a ^b Oxford English Dictionary, "Navicula. 3"
^ Navicula Diatom: Youtube video
^ Gupta, S; Agrawal, SC (2007). "Survival and motility of diatoms Navicula grimmei and Nitzschia palea affected by some physical and chemical factors". Folia Microbiol (Praha). 52 (2): 127–34. doi:10.1007/BF02932151. PMID 17575911. S2CID 20030370.
^ J Microbiol Methods. 2013 Mar;92(3):349-54. doi: 10.1016/j.mimet.2013.01.006. Epub 2013 Jan 18. Semi-circular microgrooves to observe active movements of individual Navicula pavillardii cells. Umemura K1, Haneda T, Tanabe M, Suzuki A, Kumashiro Y, Itoga K, Okano T, Mayama S.
^ Chen, Lei; Weng, Ding; Du, Chuan; Wang, Jiadao; Cao, Shan (14 May 2019). "Contribution of frustules and mucilage trails to the mobility of diatom Navicula sp". Scientific Reports. 9 (1): 7342. Bibcode:2019NatSR...9.7342C. doi:10.1038/s41598-019-43663-z. PMC 6517400. PMID 31089153.