Chrysophyta

PLANT GROUPS
(7)
Chrysophyta
Golden-brown Algae

General characteristic of the Chrysophyta
Habitat Aquatic mainly fresh water
Pigments Chlorophyll (a & c), ?-carotene & Fucoxanthin
Food reserve Fat (Leucosin)
Cell wall Cellulose, Hemicellulose often with siliceous scales
Growth form Flagellate, Coccoid, Colonial rarely filamentous
Flagella Two unequal in length & one of them has tripartite hairs
Reproduction Asexual, Sexual

Chrysophyta, or golden-brown algae, are common microscopic in fresh water. Some species are colorless, but the vast majority is photosynthetic. As such, they are particularly important in lakes, where they may be the primary source of food for zooplankton. They are not considered truly autotrophic by some biologists because nearly all chrysophyta become facultatively heterotrophic in the absence of adequate light, or in the presence of plentiful dissolved food. When this occurs, the chrysoplast atrophies and the alga may turn predator, feeding on bacteria or diatoms.

Division Chrysophyta
Class Chrysophyceae
Order Ochromonadales
Family Ochromonadaceae
Genus Ochromonas




Ochromonas single-celled naked with two unequal flagella cells spherical cylindrical to pyriform. Cells with 1-2 (rarely more) chloroplasts, with or without an eyespot and/or Pyrenoid chloroplasts sometimes much reduced and pale or completely lost after abnormal division.









Division Chrysophyta
Class Chrysophyceae
Family Synuraceae
Genus Mallomonas

Mallomonas Single-cell, flagellates, size 6 µm to > 60µm long shape globose to elongate cells covered by silica scale armour silica scales variable and taxon specific. Bristles attached to silica scales in many species, and spines on scales of a few species; typically with one visible flagellum when observed by light microscopy although some species with two visible flagella; second flagellum, if present, visible by electron microscopy;








Division Chrysophyta
Order Dinophysiales
Family Dinophyaceae
Genus Dinobryon

Dinobryon Loricate forming arbusculate colonies (rarely solitary) planktonic and free-swimming. Lorica cylindrical, vase- or funnel-shaped and often with a slightly broadened mouth; lorica consisting primarily of cellulose and protein, formed by successive loops of fibrils extruded during rotation of the cell. Cells attached to base of lorica by a thin protoplasmic strand.