Alga Jania virgata

Appearance

Jania virgata is an upright limestone algae that looks like a light purplish pink pompom.
The thallus is formed of articulated branches, cylindrical, very thin (between 0.1 and 0.2 mm in diameter), branched dichotomous or trichotome, very irregular and arranged in different planes. Calcified segments and flexible segments succeed one another, giving it a certain flexibility.
It reaches 2 to 5 cm high, and is attached to the substrate by a basal disc.
When it dies, the color turns white.

Naming

Origin of species name
Adjective (Latin), twiggy, long and slender or streaked, rod-like (Stearn 1973).

Homotypic Synonym(s)
Corallina virgata Zanardini 1841
Haliptilon virgatum (Zanardini) Garbary & H.W.Johansen 1982

Heterotypic Synonym(s)
Corallina granifera J.Ellis & Solander 1786
Jania granifera J.V.Lamouroux 1812
Lomentaria gracilis Audouin 1826

Distribution

This seaweed is present throughout the Mediterranean. In the eastern Atlantic, it is present from Ireland and the North Sea to Cape Verde, the Azores and the Canaries.
It has also been reported in Antarctica and Samoa in the Pacific, but these distant signals deserve confirmation.

Behavior

This alga grows on other algae, particularly Cladostephus, Cystoseira, Digenea, Halopytis, and Halopteris. It is often associated with other Jania.

Habitat

This alga is found all year round between 0 and 20 m deep in photophilic biotopes. It develops on other algae (epiphyte species), and on rocky substrates exposed to the current.

Reproduction

The development cycle is complex: the cycle is trigenetic isomorphous (characterized by three generations: the tetrasporophyte and the gametophyte (male or female, the species is dioecious) identical morphologically and the carposporophyte that develops in the conceptacles females. The fertile thalli differentiate their reproductive elements (tetrasporanges, male and female gametes or carposporangia) in specialized articles, intercalary at the base of the dichotomies.These fertile articles are in the form of small flasks with a central cavity or concept, and an apical or ostiol pore. During a bad season, the thallus does not change appearance during its reproductive cycle.

Food

This alga is autotrophic photosynthetic: it develops its organic compounds from carbon dioxide, mineral salts and light, thanks to pigments that allow it to photosynthesize.