| Jania | |
|---|---|
 | |
| Jania rubens | |
Scientific classification  | |
| (unranked): | Archaeplastida |
| Division: | Rhodophyta |
| Class: | Florideophyceae |
| Order: | Corallinales |
| Family: | Corallinaceae |
| Subfamily: | Corallinoideae |
| Genus: | Jania J.V. Lamouroux, 1812 [1] |
| Species | |
See text | |
Jania is a genus of red macroalgae (or seaweeds) with hard, calcareous, branching skeletons in the family Corallinaceae.
The genus name of Jania is derived from the Greek water nymph called Ianeira (or Janeria) [2] . It was first circumscribed by Jean Vincent Félix Lamouroux in 1812 [3] . Based on a recent integrated taxonomic examination of the genus, and by extension its tribe Janieae, the members of Cheilosporum and Haliptilon have all been transferred under genus Jania [4] . As a result, there is currently around 55 confirmed species for this genus [5] .
Jania is an articulated coralline algae characterized by having erect thalli with dichotomously-arranged branches composed of alternating segments of red or pink, calcified, cylindrical sections (intergeniculum) and white uncalcified sections (geniculum); that is attached to the substrate by small, stolon-like holdfasts [6] [5] . Intergenicula of this genus can be cylindrical, subcylindrical or compressed and smooth, winged or lobed [5] [4] .
Jania species are well-distributed throughout the world [5] .
Members of the genus are found in sheltered reef habitats, often in crevices or other shaded areas [7] . They are also epilithic, epiphytic, and could form free-living clumps called articuliths [8] .
Like most red seaweeds, Jania exhibit a triphasic life cycle wherein aside from the free-living haploid (gametophyte) and diploid (tetrasporophyte) generations, another diploid generation that is parasitic to the gametophyte, the carposporophyte. Tetrasporophyte (2N) generation would release four haploid spores (or tetraspores) that would later on develop into either the male and female gametophytes; moreover, the spermatium (N) produced by the spermatangia will be trapped by the trichogyne of the carpogonium (N) of the female gametophyte and later on fuse to form the zygote and subsequently develop into the carposporophyte (2N); lastly the carposporophyte will produce carpospores (2N) that will become the tetratsporophyte (2N) [5] . The unique structure involved in coralline reproduction is the presence of the conceptacle, a calcified depression wherein the tetrasporangia, spermatangia, and carposporangia are formed. [9]
There is no known cultivation technology for this genus.
Priming tomato seeds with Jania polysaccharides has shown to greatly improve the resistance of seedlings to soil-borne pathogens and consequently promote plant growth [10] .
Despite the potential use of Jania in agriculture and Due to a lack of interest on this genus, this genus is not currently being commercially utilized.
The World Register of Marine Species list the following:
Coralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of red, but some species can be purple, yellow, blue, white, or gray-green. Coralline algae play an important role in the ecology of coral reefs. Sea urchins, parrot fish, and limpets and chitons feed on coralline algae. In the temperate Mediterranean Sea, coralline algae are the main builders of a typical algal reef, the Coralligène ("coralligenous"). Many are typically encrusting and rock-like, found in marine waters all over the world. Only one species lives in freshwater. Unattached specimens may form relatively smooth compact balls to warty or fruticose thalli.
The Corallinaceae are one of the two extant Coralline families of red algae; they are differentiated from the morphologically similar Sporolithaceae by their formation of grouped sporangial chambers, clustered into sori. The Corallinoideae is monophyletic; the other subfamilies form another monophyletic group.
The Delesseriaceae is a family of about 100 genera of marine red alga.
Trichocyte in algae are cells which grow on the outside of the thallus, from which hairs grow. In algae, trichocytes grow principally over the summer; their growth is mediated by water temperature and day length.
Halymenia a genus of a macroscopic red algae that grows in oceans worldwide.
Rhodomelaceae is estimated to be the largest red algae family, with about 125 genera and over 700 species.
Bangia is an extant genus of division Rhodophyta that grows in marine or freshwater habitats. Bangia has small thalli with rapid growth and high reproductive output, and exhibits behavior characteristic of r-selected species. The plants are attached by down-growing rhizoids, usually in dense purple-black to rust-colored clumps. The chloroplasts of Bangia, like others in the division Rhodophyta, contain chlorophyll a and sometimes chlorophyll d, as well as accessory pigments such as phycobilin pigments and xanthophylls. Depending on the relative proportions of these pigments and the light conditions, the overall color of the plant can range from green to red to purple to grey; however, the red pigment, phycoerythrin, is usually dominant.
Galaxauraceae is a family of red algae (Rhodophyta) in the order Nemaliales.
Rhodymenia is a genus of red algae, containing the following species:
Amphiroa is a genus of thalloid red algae under the family Corallinaceae.
Laurencia is a genus of red algae that grow in temperate and tropical shore areas, in littoral to sublittoral habitats, at depths up to 65 m (213 ft).
Hypnea is a genus of red algae, and a well known carrageenophyte.
Cheilosporum is a genus of red algae in the family Corallinaceae.
Jania cultrata is a species of red seaweeds with a global tropical distribution.
Champia is a genus of red algae in the family Champiaceae, first described in 1809 by Nicaise Auguste Desvaux
Amphiroa beauvoisii is a species of thalloid red algae in the Corallinaceae family. It is widely distributed across the world, and can be found attached to rocks in intertidal areas. Individual organisms consist of a base of calcified material, tissue in the shape of branching fan-like planes growing out of it. It exhibits a wide range of morphologies based on where it is found, as well as different reproductive behaviors based on season and location.
Callithamnion is a genus of algae belonging to the family Callithamniaceae.
Liagoraceae is a family of red algae (Rhodophyta) in the order Nemaliales. The type genus is LiagoraJ.V.Lamouroux.