| Lithophyllum orbiculatum | |
|---|---|
 | |
| Lithophyllum orbiculatum from Castalia, Grand Manan Island, New Brunswick, Canada | |
Scientific classification  | |
| (unranked): | Archaeplastida |
| Division: | Rhodophyta |
| Class: | Florideophyceae |
| Order: | Corallinales |
| Family: | Corallinaceae |
| Genus: | Lithophyllum |
| Species: | L. orbiculatum |
| Binomial name | |
| Lithophyllum orbiculatum (Foslie) Foslie 1900 | |
Lithophyllum orbiculatum is a species of thalloid coralline algae, which are a red algae whose cell walls contain calcareous deposits.
Due to being very similar, the species of coralline algae Lithophyllum crouanii , was often misidentified as Lithophyllum orbiculatum. [1]
This species is often found in the north of the Atlantic Ocean and in the Mediterranean Sea. [2] It has also been collected in the Indian Ocean more recently. [3] The coralline algae lives in the mid-tide and higher level pools, occasionally exposed to air. [4] The coralline algae mostly grows on hard rock surfaces and was not found on any limestone or slate rock. [4] It can also be found growing on the shells of mollusks that live in the same area, however the algae was physically reduced on the shells. [4] Over time the coralline algae will come together on the surfaces to form large colonies and cover the vast majority of a surface. [4]
The coralline algae often acts as a pioneer that first colonizes new surfaces and prepares it for colonization by other organisms. [4] It sheds its epithallus occasionally in order to prevent other organisms growing over it. [5] Still, it is often overgrown by Lithophyllum incrustans in what is considered ecological succession. [4]
The coralline algae has a rough and chalky texture, and the color can range from grey, brown, and pink. They are thin and will attach very strongly to the surface. The individuals of the species are small, when young the algae's diameter can be up to 8 mm, but when mature the diameter is around 25 mm. Younger specimens will be relatively thin, up to 1 mm thick, with their margins being attenuated and crimped. The mature specimens are thicker and have irregular shapes. Specimens found in areas prone to exposure have thalli that form protuberances that may reach 5 mm tall. [4]
The coralline algae reproduces during the winter, approximately from October to February. [4] They reproduce using uniporate conceptacles, which are cavities where the reproductive organs of algae are found. [6] The algae may be tetrasporangial, spermatangial, or carposporangial reproduction types. Depending on which type the algae is, the conceptacles will vary in size. [4]
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 history of phycology is the history of the scientific study of algae. Human interest in plants as food goes back into the origins of the species and knowledge of algae can be traced back more than two thousand years. However, only in the last three hundred years has that knowledge evolved into a rapidly developing science.
Conceptacles are specialized cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole. Conceptacles are present in Corallinaceae, and Hildenbrandiales, as well as the brown Fucales. In the Fucales there is no haploid phase in the reproductive cycle and therefore no alternation of generations. The thallus is a sporophyte. The diploid plants produce male (antheridia) and female (oogonia) gametangia by meiosis. The gametes are released into the surrounding water; after fusion, the zygote settles and begins growth.
Wataru Ishijima was a paleontologist and geologist. Ishijima was one of the most prolific researchers of fossil calcareous algae. After graduating from the Imperial Fisheries Institute in 1927, Ishijima joined the Institute of Geology and Paleontology, Faculty of Science, Tohoku Imperial University (Sendai) from 1927–1931. He then worked at the Institute of Geology, Taihoku Imperial University (Taipei) during 1942–1945 and then at the Rikkyo University (Tokyo) from 1945–1980. His doctoral dissertation was submitted to Tohoku University and was privately published by Yūhodō. He described a total of 139 taxa of fossil calcareous algae including at least 114 species of Corallinales, and he produced more than 45 publications on coralline algal taxonomy.
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.
Phymatolithon is a genus of non geniculate coralline red algae, known from the UK, and Australia. It is encrusting, flat, and unbranched; it has tetrasporangia and bisporangia borne in multiporate conceptacles. Some of its cells bear small holes in the middle; this distinctive thallus texture is termed a "Leptophytum-type" thallus surface, and has been posited as a taxonomically informative character. It periodically sloughs off its epithallus, reducing its overgrowth by algae by as much as 50% compared to bare rock.
The Rhodogorgonales are an order of red algae, a sister group to the corallines. They are always thalloid and calcified; their calcification is very different from the corallines, as individual calcite crystals are deposited in the cell wall of specialised cells; this suggests that the evolution of calcification may have been independent from the corallines. They have no fossil record.
Lithophyllum is a genus of thalloid red algae belonging to the family Corallinaceae.
Hildenbrandia is a genus of thalloid red alga comprising 26 species. The slow-growing, non-mineralized thalli take a crustose form. Hildenbrandia reproduces by means of conceptacles and produces tetraspores.
The Sporolithaceae are one of the two extant families of coralline algae. They are differentiated from the other family, the Corallinaceae, by their formation of conceptacles with one or many pores.
The Mastophoroideae are a subfamily of Corallinaceaen coralline algae with uniporate conceptacles.
The Lithophylloideae are a monophyletic subfamily of Corallinaceaen Coralline algae with uniporate conceptacles.
Spongites yendoi is a species of crustose red seaweed with a hard, calcareous skeleton in the family Corallinaceae. It is found on the lower shore as part of a diverse community in the southeastern Atlantic Ocean and the Indo-Pacific Ocean.
Melobesia membranacea is a small marine alga encrusting on the surface of other algae. In the division of the Rhodophyta.
Michael Dominic Richard Guiry, is an Irish botanist, who specialises in phycology (algae). See for example the articles. He is the founder and director of the algal database, AlgaeBase.
Sporolithon ptychoides is a species of crustose red seaweed with a hard, calcareous skeleton in the family Corallinaceae. It has a widespread distribution, being present in the Pacific and Indian Oceans, the Mediterranean Sea and the southwestern Atlantic Ocean.
Lithophyllum incrustans is a small pinkish species of seaweed.
Phymatolithon lenormandii is a common red alga.
Lithothamnion glaciale is the botanical name for a species of multicellular red algae of the genus Lithothamnion, subfamily Melobesioideae.
