Peyssonneliales
Peyssonneliales is a monotypic order of red algae belonging to the class Florideophyceae and the subclass Rhodymeniophycidae. It contains only one known family, Peyssonneliaceae.
The type species is Peyssonnelia.
History
Genera Peyssonnelia and Sonderopelta were originally in order Gigartinales but comparative morphology and rbcL and nuclear LSU rRNA sequence data showed that they were separate and therefore order Peyssonneliales was established in 2009 to hold them both.Incendia was initially resolved as a monophyletic clade with full support for rbcL. Then using robust rbcL phylogeny, order Peyssonneliales was lso resolved as monophyletic with well-supported main lineages.
Description
Delineation of the various genera in the Peyssonneliaceae had mostly been based on vegetative characteristics.Peyssonneliales order algae are red, crustose, prostrate, and usually epilithic. The crusts may be non-calcified throughout, calcified throughout, or partially calcified. Calcium carbonate, if present, is in the mineral form aragonite. The lower surfaces of the crusts are partially to completely attached to the sub-stratum, either directly or by unicellular or multi cellular rhizoids. Prostrate growth is by radiating marginal rows of transversely dividing apical initials in the basal layer. These growths then later divide vertically to form a single upper or lower perithallial cell. The first section of the perithallial cells gives rise to simple or branched filaments that together form a loose to compact upper- only cortex or upper and lower cortices. Cortical cells have numerous discoid or ribbon- like chloroplasts.
The red algae colour comes from photosynthetic pigments. Then the various blends of relative amounts of these 3 and chlorophyll, influences the plant colour, which can vary from dark red to blue, brown, or greenish.
Genera
As accepted by AlgaeBase ;Agissea - 14 spp.Brasilophycus - 2 spp.Chevaliericrusta - 1 sp.Cruoriella - 4 spp.Cruoriopsis - 4 spp.Incendia - 10 spp.Metapeyssonnelia - 5 spp.Olokunia - 5 spp.Peyssonnelia - 68 spp.Piriora - 1 sp.Polystrata - 6 spp.Pulvinia - 1 sp.Ramicrusta - 19 spp.Rhodowynnea - 3 spp.Riquetophycus - 1 sp.Seiria - 2 spp.Sonderophycus - 4 spp.Squamaria - 1 sp.Former genera; Gymnosorus, Haematostagon, Lithymenia, Nardoa and
Sonderopelta
WoRMS doesn't accept the genera; Agissea, Brasilophycus, Olokunia, Piriora, Rhodowynnea and Squamaria.
It also notes; Cruoriopsis is accepted as synonym of Peyssonnelia,
Haematostagon is accepted as synonym of Peyssonnelia,
Lithymenia is accepted as synonym of Peyssonnelia
Sonderopelta is accepted as synonym of Sonderophycus.
Distribution
The order has cosmopolitan distribution, worldwide. They are found in places such as Brazil, western Atlantic Ocean, San Andres Island,, Jamaica, Puerto Rico, Gulf of California, Hawaii, Azores, Brittany in France, southern Australia, New Zealand, also parts of Asia.They can grow at low depths, from the Intertidal zone,, or down to depths as low as below sea level in the Pacific Ocean.
Members of Peyssonneliales can be found growing on hard substratum, or found growing on corals.