Yellow-green Algae

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Related to Xanthophyta: Chrysophyta, Cyanophyta, Bacillariophyta

yellow-green algae

[′yel·ō ¦grēn ′al·jē]
(botany)
The common name for members of the class Xanthophyceae.

Yellow-green Algae

 

(Xanthophyta, also Heterocontae), a division (phylum) of plants. They are unicellular, colonial, or multicellular organisms, free-swimming or sessile, with yello wish-green chromatophores containing, besides chlorophyll, a large quantity of yellow pigments— xanthophyll and β-carotene. They are found chiefly in fresh water and sometimes in soil and sea water. The majority of yellow-green algae are autotrophic organisms that synthesize oils, volutin, and other substances; some of the yellow-green algae are heterotrophic organisms, and a few are holozoic. Some unicellular yellow-green algae are motile and have pulsating vacuoles and eyelets and usually two flagella of different length and structure (hence the second name— Heterocontae). The cells of the yellow-green algae are mononuclear, more rarely polynuclear, and are often surrounded by a hard sheath of two halves containing principally pectin. Yellow-green algae reproduce by binary fission, zoospores, and nonmotile spores. The sexual process, isogamy, is known in only two genera. Spores and cysts are the resting forms. In the USSR, 82 genera (344 species) of freshwater yellow-green algae are known.

IU. E. PETROV

References in periodicals archive ?
x DIVISION: XANTHOPHYTA Vacuolaria virescens Cienkowski Sitios de muestreo Especies P4 P5 P6 CYANOBACTERIA Chroococcus sp.
En febrero, el numero de especies llego a 100 perteneciendo a las divisiones Chlorophyta (30%), Heterokonthophyta (29%), Euglenophyta (20%), Cyanophyta (19%), Xanthophyta (1%) y Pyrrophyta (1%; tabla 2).
En esta zona Chlorophyta presento la mayor riqueza especifica con 62 especies correspondientes al 31% de las especies registradas para este punto, 45 especies pertenecian a la division Euglenophyta (24%), a Heterokonthophyta 42 (22%), Cyanophyta 36 (19%), Xanthophyta y Pyrrophyta 3 especies cada una (4%).
Aunque las Chlorophytas presentaron la mayor riqueza especifica la division Cyanophyta fue la mas abundante con 5095 ind/L (63%), especialmente de tipos filamentosas o delgadas, seguida de las divisiones Chlorophyta con 1697 ind/L (21%), Heterokonthophyta con 1124 ind/L(14%), Euglenophyta 143 ind/L(l,77%), Xanthophyta con 19 ind/L y Pyrrophyta con 3 ind/L (22%; Figura 3).
En orden de abundancia tambien se registraron las divisiones Heterokonthophyta con 308 ind/L (10,10%), Chlorophyta con 256 ind/L (8,39%), Euglenophytas con 50 ind/L ( 1,64%) y Xanthophyta con 3 ind/L (0,1 %).
Se reportaron 2476 ind/L en la zona litoral, donde la division con mayor numero de individuos fue Cyanophyta con 1757 ind/L (70,96%), seguida de Chlorophyta con 298 ind/L(12,04%), Heterokonthophyta con 277 ind/L (11,19%), Euglenophyta con 76 ind/L (3,07%), Pyrrophyta con 56 ind/L (2,26%) y Xanthophyta con 12 ind/L (0,48%).