Hildenbrandia

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Hildenbrandia
Hildenbrandia crouaniorum 008.JPG
The darker red alga encrusting this rock fragment is H. crouaniorum
Hildenbrandia rivularis gemma SEM.jpg
SEM of a H. rivularis gemma. Scale bar: 50 μm
Scientific classification OOjs UI icon edit-ltr.svg
(unranked): Archaeplastida
Division: Rhodophyta
Class: Florideophyceae
Order: Hildenbrandiales
Family: Hildenbrandiaceae
Genus: Hildenbrandia
Nardo, 1834
Synonyms

Hildenbrandtia

Hildenbrandia is a genus of thalloid red alga comprising about 26 species. The slow-growing, non-mineralized thalli take a crustose form. [1] Hildenbrandia reproduces by means of conceptacles and produces tetraspores.

Contents

Morphology

Hildenbrandia cells are around 3–5 μm in diameter and the filaments are around 50–75 μm in height. [2]

The thallus comprises two layers: the hypothallus, which attaches to the rock, and the perithallus, a pseudoparenchymous layer comprising vertical filaments, which unlike coralline red algae is not further differentiated. [3] [4]

Growth

Hildenbrandia comprises orderly layers of vertical oblong cells with thick vegetative cell walls, occasionally connected by secondary pit connections with pit plugs in the septal pores. [5] It grows at its margins, away from the centre, and is able to quickly repair any gaps arising by regenerating from a basal layer of cells. [6] As plants become more mature, they become multi-layered and strongly pigmented near their centres, whilst their single-layered margins begin to grow more slowly. [6] Multi-layered areas may develop in the margins; these will detach and float away as gemmae to form new colonies, leaving a single layer of cells beneath them once they separate from the host plant. [6]

Newly settled gemmae form rhizoids. [7]

Conceptacles develop in a haphazard manner; cells in conceptacle regions deform one another and become less regularly shaped as they grow larger. [5]

In a similar fashion to the coralline algae, the outer layer of the thallus is shed seasonally, presumably to avoid colonization by epiphytes. [8]

Taxonomy

The genus name of Hildenbrandia is in honour of Franz Xaver von Hildenbrand (1789-1849), who was an Austrian physician and botanist. [9]

The genus was circumscribed by Giovanni Domenico Nardo in Isis (Oken) vol.27 on page 675 in 1834.

Habitat

The freshwater species H. rivularis [6] and H. angularis [7] seems to form a clade, [10] and require an alkaline pH and hard water, preferring clean water. [11] Unlike most other freshwater red algae (which prefer running water), H. rivularis prefers still water, particularly shady lakes or ponds. [11] H. rubra and other marine species are found in brackish waters, but freshwater / gemma-bearing species cannot tolerate even moderate salinities. [12] The genus is often found in a symbiotic partnership with fungi. [13] Hildenbrandia has a remarkable tolerance to stresses including extreme temperatures, desiccation, and Ultra-violet light; it can be up and photosynthesizing near full capacity just minutes after being cooled to −17 °C or subjected to extreme salinities. [14]

Reproduction

Sexual reproduction has never been observed in any Hildenbrandia species. [12] It can reproduce by splitting into multiple colonies by fragmentation, or via stolons (i.e. sending out lateral branches) or gemmae. [6]

Marine Hildenbrandia, on the other hand, reproduce by means of tetraspores that are produced within the thallus by conceptacles. [7]

Systematics

The genus contains these species [15] (this list is out of date):

As of April 2022, the GBIF only accepts 6 species; Hildenbrandia crouaniorumJ.Agardh, Hildenbrandia dawsonii, Hildenbrandia occidentalisSetch., 1917, Hildenbrandia rivularis(Liebman) J.Agardh, Hildenbrandia rubra(Sommerfelt) Meneghini and Hildenbrandia sanjuanensis. [16]

Stonehenge

The presence of H. rivularis near Stonehenge has been put forward as a reason for the site's perceived mystical properties. Flint in the Blick Mead spring pools near to the henge takes on a pink hue a couple of hours after being taken out of water due to the presence of the algae. It is assumed that ancient hunter-gatherers would have seen the rocks as having magical properties and would have deemed the site worthy of interest. [17] [18]

Related Research Articles

<span class="mw-page-title-main">Coralline algae</span> Order of algae (Corallinales)

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.

<span class="mw-page-title-main">Florideophyceae</span> Class of algae

Florideophyceae is a class of exclusively multicellular red algae. They were once thought to be the only algae to bear pit connections, but these have since been found in the filamentous stage of the Bangiaceae. They were also thought only to exhibit apical growth, but there are genera known to grow by intercalary growth. Most, but not all, genera have three phases to the life cycle.

<span class="mw-page-title-main">Conceptacle</span>

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.

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.

<i>Peyssonnelia</i> Genus of algae

Peyssonnelia is a genus of thalloid red alga, named after naturalist Jean-André Peyssonnel (1694–1759) It includes the algae commonly known as rumoi-iwanokawa, mayoi-iwanokawa and akase-iwanokawa. Specimens can reach around 20 cm in size. Peyssonnelia produces tetraspores.

<span class="mw-page-title-main">Hildenbrandiales</span> Order of algae

Hildenbrandiales is an order of crustose forms red alga which bear conceptacles and produce secondary pit-connections. They reproduce by vegetative gemmae as well as tetrasporangia, which are produced inside the conceptacles. The way in which the tetraspores are produced is unusual enough to justify the formation of this distinct order. Some members of the order are known from freshwater rivers as well.

<span class="mw-page-title-main">Red algae</span> Division of archaeplastids

Red algae, or Rhodophyta, are one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity.

<i>Apophlaea</i> Genus of algae

Apophlaea is a genus of thalloid algae that is endemic to New Zealand. This genus has two species, both from the high intertidal zone on New Zealand's coasts. Specimens can reach around 15 cm in size. The thalli take a crustose form, but also contain upright, branching frond-like protrusions that reach 5–8 cm in height. Secondary pit connections and secondary pit connectionsare present in the organisms. Apophlaea reproduces by means of conceptacles; it produces tetraspores.

Archaeolithophyllum is a genus of conceptacle-bearing red alga that falls in the coralline stem group. It somewhat resembles Lithophyllum.

Synarthrophyton is a genus of thalloid red algae comprising eight species. The monomerous, crustose thalli are composed of a single system of filaments which grow close to the underlying surface. Synarthrophyton reproduces by means of flask-shaped multiporate conceptacles; it produces tetraspores and dispores. Mucus plugs the opening of young conceptacles, which open as they mature.

<i>Amphiroa</i> Genus of algae

Amphiroa is a genus of thalloid red algae under the family Corallinaceae.

<i>Hypnea</i> Genus of algae

Hypnea is a genus of red algae, and a well known carrageenophyte.

Pyropia virididentata, formerly known as Porphyra virididentata, is a red alga species in the genus Pyropia. It is endemic to New Zealand. It is monostromatic, monoecious, and grows in the intertidal zone, predominantly on rock substrata. With Porphyra cinnamomea, Pyropia rakiura and Clymene coleana, they can be distinguished by morphology, as well as geographical, ecological and seasonal distribution patterns, and importantly, chromosome numbers, which in this species n = 3. Finally, these four species are distinguished by a particular nucleotide sequence at the 18S rDNA locus.

Sirodotia Kylin (1912) is a genus of freshwater red alga which was described by Kylin in 1912, and placed in the Batrachospermaceae family.

<span class="mw-page-title-main">Batrachospermaceae</span> Family of algae

Batrachospermaceae is a family of fresh water red algae (Rhodophyta). Genera within the Batrachospermaceae generally have a "Lemanea-type" life history with carpospores germinating to produce chantransia. Sporophyte phase with meiosis occurs in an apical cell to produce the gametophyte stage. Pit connections have two pit plug cap layers with the other layer enlarged. This family of freshwater red algae is uniaxial, meaning each filament with a single apical cell. The genera included within Batrachospermaceae are listed in the table below.

<i>Hildenbrandia rubra</i> Species of alga

Hildenbrandia rubra is a marine species of thalloid red alga. It forms thin reddish crusts on rocks and pebbles in the intertidal zone and the shallow subtidal zone. It is a common species with a cosmopolitan distribution, and is able to tolerate a wide range of conditions.

Crustaphytum is a genus of red alga first discovered in Taoyuan algal reefs by Taiwanese scientists. The epithet “crusta” refers to crustose thallus and “phytum” refers to plant. Belonging to the family Hapalidiaceae in the order Hapalidiales, Crustaphytum is one kind of crustose coralline algae.

<span class="mw-page-title-main">Thoreales</span> Order of algae

Thoreales is an order of red algae belonging to the class Florideophyceae. The order consists only one family, ThoreaceaeHassall, 1845. The family of Thoreaceae was circumscribed by Arthur Hill Hassall in A history of the British freshwater algae, including descriptions of the Desmideae and Diatomaceae in 1845.

<span class="mw-page-title-main">Peyssonneliales</span> Order of algae

Peyssonneliales is a monotypic order of red algae belonging to the class Florideophyceae and the subclass Rhodymeniophycidae. It contains only 1 known family, PeyssonneliaceaeDenizot, M., 1968.

Kathleen "Kay" Margaret Cole was a Canadian phycologist, known as one of the world's leading experts in the cytology of marine algae. In 1998 the Canadian Botanical Society awarded her the George Lawson Medal for lifetime achievement.

References

  1. ↑ Dethier, M. (1994). "The ecology of intertidal algal crusts: variation within a functional group". Journal of Experimental Marine Biology and Ecology. 177: 37–71. doi:10.1016/0022-0981(94)90143-0.
  2. ↑ Sherwood, A.; Sheath, R. (2000). "Biogeography and systematics of Hildenbrandia (Rhodophyta, Hildenbrandiales) in Europe: inferences from morphometrics and rbcL and 18S rRNA gene sequence analyses". European Journal of Phycology. 35 (2): 143–152. doi: 10.1080/09670260010001735731 .
  3. ↑ "Hildenbrandia Ben: Morphology". washington.edu.
  4. ↑ Cabioch, J.; Giraud, G. (1982). "La structure hildenbrandioïde, stratégie adaptative chez les Florideés". Phycologia (in French). 21 (3): 308–315. doi:10.2216/i0031-8884-21-3-307.1.
  5. 1 2 Pueschel, C. (1982). "Ultrastructural observations of tetrasporangia and conceptacles in Hildenbrandia (Rhodophyta: Hildenbrandiales)". European Journal of Phycology. 17 (3): 333–341. doi:10.1080/00071618200650331.
  6. 1 2 3 4 5 Wayne Nichols, H. (1965). "Culture and development of Hildenbrandia rivularis from Denmark and North America". American Journal of Botany. 52 (1): 9–15. doi:10.2307/2439969. JSTOR   2439969.
  7. 1 2 3 Sherwood, A. R.; Sheath, R. G. (2000). "Microscopic analysis and seasonality of gemma production in the freshwater red alga Hildenbrandia angolensis (Hildenbrandiales, Rhodophyta)". Phycological Research. 48 (4): 241–249. doi:10.1046/j.1440-1835.2000.00208.x. S2CID   84193742.
  8. ↑ Pueschel, C. (1988). "Cell sloughing and chloroplast inclusions in Hildenbrandia rubra (Rhodophyta, Hildenbrandiales)". European Journal of Phycology. 23: 17–23. doi:10.1080/00071618800650021.
  9. ↑ Burkhardt, Lotte (2022). Eine Enzyklopädie zu eponymischen Pflanzennamen [Encyclopedia of eponymic plant names](pdf) (in German). Berlin: Botanic Garden and Botanical Museum, Freie Universität Berlin. doi:10.3372/epolist2022. ISBN   978-3-946292-41-8 . Retrieved January 27, 2022.
  10. ↑ Sherwood, A. R.; Sheath, R. G. (2003). "Systematics of the Hildenbrandiales (Rhodophyta): gene sequence and morphometric analyses of global collections". Journal of Phycology. 39 (2): 409–422. doi:10.1046/j.1529-8817.2003.01050.x. S2CID   86786840.
  11. 1 2 Eloranta, P.; Kwandrans, J. (2004). "Indicator value of freshwater red algae in running waters for water quality assessment" (PDF). International Journal of Oceanography and Hydrobiology. XXXIII (1): 47–54. ISSN   1730-413X. Archived from the original (PDF) on 2011-07-27. Retrieved 2010-10-27.
  12. 1 2 Sherwood, A. R.; Shea, T. B.; Sheath, R. G. (2002). "European freshwater Hildenbrandia (Hildenbrandiales, Rhodophyta) has not been derived from multiple invasions from marine habitats". Phycologia. 41: 87–95. doi:10.2216/i0031-8884-41-1-87.1. S2CID   84894072.
  13. ↑ Saunders, G. W.; Bailey, J. C. (1999). "Molecular systematic analyses indicate that the enigmatic Apophlaea is a member of the Hildenbrandiales (Rhodophyta, Florideophycidae)". Journal of Phycology. 35: 171–175. doi:10.1046/j.1529-8817.1999.3510171.x. S2CID   84758802.
  14. ↑ Garbary, D. (2007). "The Margin of the Sea". Algae and Cyanobacteria in Extreme Environments. Cellular Origin, Life in Extreme Habitats and Astrobiology. Vol. 11. pp. 173–191. doi:10.1007/978-1-4020-6112-7_9. ISBN   978-1-4020-6111-0.
  15. ↑ Guiry, M.D.; Guiry, G.M. (2008). "Hildenbrandia". AlgaeBase . World-wide electronic publication, National University of Ireland, Galway. Retrieved 2009-04-18.
  16. ↑ "Hildenbrandia Nardo, 1834". www.gbif.org. Retrieved 7 April 2022.
  17. ↑ "Mesolithic settlement near Stonehenge: excavations at Blick Mead, Vespasian's Camp, Amesbury" (PDF). www.silversaffron.co.uk.
  18. ↑ Jacques, David (2014). "Mesolithic settlement near Stonehenge: excavations at Blick Mead, Vespasian's Camp, Amesbury". Wiltshire Archaeological and Natural History Magazine . 107: 7–27.
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