Halymeniales is an order of
red algae
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...
belonging to the class
Florideophyceae and the subclass
Rhodymeniophycidae
Florideophyceae is a class of 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 ...
.
The
type species is ''
Halymenia
''Halymenia'' a genus of a macroscopic red algae that grows in oceans worldwide.
Species have been found in cold temperate areas but the highest diversity is found in warm temperate and tropical regions. For example, 41 names have been reported ...
'' .
The red algae colour comes from photosynthetic pigments (
phycoerythrin
Phycoerythrin (PE) is a red protein-pigment complex from the light-harvesting phycobiliprotein family, present in cyanobacteria, red algae and cryptophytes, accessory to the main chlorophyll pigments responsible for photosynthesis.The red pigmen ...
,
phycocyanin,
allophycocyanin). Then the various blends of relative amounts of these 3 and
chlorophyll
Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to a ...
, influences the plant colour, which can vary from dark red to blue, brown, or greenish.
History
In 1996, Saunders and Kraft recognized a new name, the Halymeniales, for the red algal order that was previously known as the ''Cryptonemiales'' , based on small-subunit
rRNA phylogenetic analyses. The adapted order of Halymeniales originally held the families of ''Halymeniaceae'' and ''Sebdeniaceae'' , and it was characterized by taxa with a multi-axial
thallus, non-procarpic female reproductive development, outwardly directed carpogonial branches and intercalary auxiliary cells (Saunders and Kraft, 1996). Later Saunders and Kraft in 2002, transferred the genus ''Tsengia'' from the
Nemastomatales
Nemastomatales is an order of red algae. It includes some members of the defunct order Cryptonemiales.
References
Red algae orders
Florideophyceae
{{red alga-stub ...
order into the Halymeniales with the establishment of the new mono-generic family ''Tsengiaceae''. The ''Sebdeniaceae'' family was later removed from the Halymeniales and elevated to a new order,
Sebdeniales (by Withall and Saunders, 2006) as suggested by Gavio et al. (2005). Later, Papenfuss (1955) synonymized the ''Grateloupiaceae'' with the ''Cryptonemiaceae''; however, Guiry (1978) reinstated the ''Halymeniaceae'' based on nomenclatural priority. As a consequence, the ''Grateloupiaceae'' and ''Cryptonemiaceae'' are now considered synonyms of the ''Halymeniaceae''. After using a taxon-rich rbcL data set, the family ''Grateloupiaceae'' was reinstated into the ''Halymeniales'' order in 2021.
The ''Archaeolithophyllaceae'' family was created in 1987, and placed within the
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 re ...
(Order), before being placed within the Halymeniales.
Families
As accepted by
AlgaeBase (with number of species per family);
*
Archaeolithophyllaceae - 4 spp.
*
Grateloupiaceae - 116 spp.
*
Halymeniaceae - 227 spp.
*
Tsengiaceae - 12 spp.
WoRMS only accepts Halymeniaceae and Tsengiaceae and not the other 2 families
Distribution
The order has
cosmopolitan distribution
In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...
.
They are found in places such as
Tasmania (Australia), Brazil, within the Mediterranean, near the island of
Madagascar (within the
Indian Ocean),
the
Philippines,
Vietnam,
[Isabella Aiona Abbott ] the South Korean coast (East and South) and near Japan.
Species notes
''
Polyopes affinis'' is a red alga from the order Halymeniales. The species is abundantly found along the South Korean coast (East and South) and also in Japan, and it is widely used as a food in South Korea, Japan, and China because of its nutritional properties and health benefits (Ha et al. 2022).
[
Also, '']Halymenia durvillei
''Halymenia'' a genus of a macroscopic red algae that grows in oceans worldwide.
Species have been found in cold temperate areas but the highest diversity is found in warm temperate and tropical regions. For example, 41 names have been reported ...
'' is a red seaweed with a great potential as sulphated galactan producer.[
]
References
{{Taxonbar, from=Q3126286
Red algae orders