Cannabaceae

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Rhodochorton
Rhodochorton purpureum
Scientific classification Edit this classification
(unranked): Archaeplastida
Division: Rhodophyta
Class: Florideophyceae
Order: Acrochaetiales
Family: Acrochaetiaceae
Genus: Rhodochorton
Nägeli[1]
Species

Rhodochorton is a genus of filamentous red alga adapted to low light levels. It may form tufts or a thin purple "turf" up to 5 millimetres high. The filaments branch infrequently, usually at the tips.[2]

Morphology[edit]

In most species of Rhodochorton, the spore does not persist in the mature plant; instead, a basal web of filaments acts as a holdfast. Indeed, all Rhodochorton species have distinct basal threads, usually forming a disc, and upright threads, which are typically thinner.[2] Lateral branches usually occur at or near the top of the patent cell, and branching is concentrated towards the tips of threads.[2]

Ecology[edit]

The organism may encrust bare rock surfaces, or be epiphytic upon frondose algae - particularly Laminaria hyperborea.[3] It typically grows in the shadow of these larger algae, in the intertidal zone,[4] and its adaption to low light levels means it is also common in caves.[2] It reproduces in winter using tetrasporangia and don't bear any monosporangia.[5] Rhodochorton is typically marine, but R. investiens dwells in fresh water.[6] Sexual reproduction has never been observed.[7]

It suffers grazing pressure from gastropods and amphipods, but amazingly fragments of the algae are able to pass through the grazers' digestive tracts alive - grazing may actually form a mode of dispersal for the organism.[4]

Life history[edit]

Rhodochorton investiens displays a relatively simple life cycle for a red alga.[8]

In the Carposporophyte: a spermatium merges with a trichogyne (a long hair on the female sexual organ), which then divides to form carposporangia - which produce carpospores.

Carpospores germinate into gametophytes, which produce sporophytes. Both of these are very similar; they produce monospores from monosporangia "just below a cross wall in a filament"[8] and their spores are "liberated through apex of sporangial cell."[8]

The spores of a sporophyte produce tetrasporophytes. Monospores produced by this phase germinate immediately, with no resting phase, to form an identical copy of parent. Tetrasporophytes may also produce a carpospore, which germinates to form another tetrasporophyte.[verification needed][8]

The gametophyte may replicate using monospores, but produces sperm in spermatangia, and "eggs"(?) in carpogonium.[8]

See also[edit]

The species in the genus Rhodothamniella closely resemble Rhodochorton

References[edit]

  1. ^ Dixon, 1982:64
  2. ^ a b c d Fritsch, F. E. (1945), The structure and reproduction of the algae, Cambridge: Cambridge Univ. Press, ISBN 978-0-521-05042-5, OCLC 223742770
  3. ^ "Rhodochorton purpureum". www.horta.uac.pt. Archived from the original on 4 March 2016. Retrieved 29 May 2018.
  4. ^ a b Breeman, A. M.; Hoeksema, B. W. (1987), "Vegetative propagation of the red alga Rhodochorton purpureum by means of fragments that escape digestion by herbivores", Mar. Ecol. Prog. Ser., 35: 197–201, Bibcode:1987MEPS...35..197B, doi:10.3354/meps035197
  5. ^ West, John A. (1969), "The Life Histories Of Rhodochorton Purpureum And R. Tenue In Culture", Journal of Phycology, 5 (1): 12–21, Bibcode:1969JPcgy...5...12W, doi:10.1111/j.1529-8817.1969.tb02569.x, PMID 27097245, S2CID 42652370.
  6. ^ Swale, E. M. F.; Belcher, J. H. (April 1, 1963), "Morphological Observations on Wild and Cultured Material of Rhodochorton investiens (Lenormand) nov. comb. (Balbiania investiens (Lenorm.) Sirodot)", Annals of Botany, 27 (2): 282–290, doi:10.1093/oxfordjournals.aob.a083845, archived from the original on April 15, 2013
  7. ^ West, John A. (1970), "A Monoecious Isolate Of Rhodochorton purpureum", Journal of Phycology, 6 (4): 368–370, doi:10.1111/j.0022-3646.1970.00368.x.
  8. ^ a b c d e Lee, R.E. (2008), Phycology, 4th edition, Cambridge University Press, ISBN 978-0-521-63883-8
source: https://en.wikipedia.org/wiki/Rhodochorton

One thought on “Cannabaceae”

  1. Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
    View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction

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