''Synura'' is a genus of colonial

chrysomonad The Chrysophyceae, usually called chrysophytes, chrysomonads, golden-brown algae, or golden algae, are a large group of algae, found mostly in freshwater. Golden algae is also commonly used to refer to a single species, '' Prymnesium parvum'', wh ...

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

covered with

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant f ...

scales. It is the most conspicuous genus of the order

Synurales The synurids (order Synurales) are a small group of heterokont algae, found mostly in freshwater environments, characterized by cells covered in silica scales. Characteristics They are covered in silicate scales and spines. In ''Synura'', thes ...

Description

Species of ''Synura'' form microscopic, spherical

colonies A colony is a territory subject to a form of foreign rule, which rules the territory and its indigenous peoples separated from the foreign rulers, the colonizer, and their '' metropole'' (or "mother country"). This separated rule was often or ...

, composed of multiple cells attached to each other at the center of the colony. ''Synura'' cells are variously shaped, typically spherical to pear-shaped or club-shaped. Each cell contains two

plastid A plastid is a membrane-bound organelle found in the Cell (biology), cells of plants, algae, and some other eukaryotic organisms. Plastids are considered to be intracellular endosymbiotic cyanobacteria. Examples of plastids include chloroplasts ...

s aligned with the long axis of the cell; they impart a distinctive golden color to the cells, which comes from chlorophyll ''c₁'' and

fucoxanthin Fucoxanthin is a xanthophyll, with formula C42H58O6. It is found as an accessory pigment in the chloroplasts of brown algae and most other heterokonts, giving them a brown or olive-green color. Fucoxanthin absorbs light primarily in the blue-gree ...

. Cells are covered with scales made of

. Two

flagella A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many pr ...

are present. Identification of species depends on the

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

of the scales. For many species, a positive identification is only possible with an

electron microscope An electron microscope is a microscope that uses a beam of electrons as a source of illumination. It uses electron optics that are analogous to the glass lenses of an optical light microscope to control the electron beam, for instance focusing it ...

, either with

scanning electron microscopy A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that ...

(SEM) or

transmission electron microscopy Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a g ...

(TEM).

Classification

''Synura'' is the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

and only genus in the family Synuraceae. The present taxonomy recognizes five sections: *Section Peterseniae **'' S. americana'' **'' S. australiensis'' **'' S. borealis'' **'' S. conopea'' **'' S. glabra'' **'' S. heteropora'' **'' S. hibernica'' **'' S. laticarina'' **'' S. longisquama'' **'' S. macracantha'' **'' S. macropora'' **'' S. petersenii'' *Section Spinosae **'' S. curtispina'' **'' S. mollispina'' **'' S. nygaardii'' **'' S. sphagnicola'' **'' S. spinosa'' *Section Echinulatae **'' S. biseriata'' **'' S. echinulata'' **'' S. leptorrhabda'' **'' S. mammillosa'' **'' S. multidentata'' *Section Splendidae **'' S. splendida'' *Section Uvellae **'' S. uvella''

References

Chrysophyceae Golden algae genera Taxa named by Christian Gottfried Ehrenberg Taxa described in 1834 {{Heterokont-stub