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Detailed morphological studies and molecular analyses based on plastid-encoded rbcL gene sequences were undertaken on Peyssonnelia species, a poorly known genus from Korea. We report new records for the Korean coast, Peyssonnelia harveyana and P. rumoiana. Peyssonnelia harveyana is chiefly characterized by P. rubra-type anatomy, closely packed perithallial filaments in firm matrix, hypothallial filaments arranged in parallel rows, thalli with appressed margins, hypobasal calcification, and unicellular rhizoids. Peyssonnelia rumoiana is principally characterized by two vegetative features, hypothallial filaments arranged in a polyflabellate layer, and perithallial filaments arising from the whole upper surface of each hypothallial cell (Peyssonnelia rubra-type anatomy). Our rbcL analyses revealed that P. harveynana and P. rumoiana were placed within a clade of Peyssonnelia. We also propose the new combination, Sonderophycus cauliferus comb. nov., for previous Peyssonnelia caulifera. Phylogenetic analyses revealed that our S. cauliferus was placed within a clade of Sonderophycus.

The macroalgal flora associated with rhodolith beds in the Bay of Islands, northeastern North Island, was investigated as part of the first detailed study of subtidal rhodoliths in New Zealand. The rhodolith beds differed in their physical characteristics and in the dominant rhodolith-forming species present, one bed with clear water and predominantly Lithothamnion crispatum rhodoliths, and the other bed with turbid water, and Sporolithon durum rhodoliths covered by fine sediments. One hundred and three taxa were identified (12 green, 24 brown and 67 red algae), with similar numbers of taxa found in the two seasons sampled. The floral composition at the two beds differed significantly. The flora included range extensions for species previously reported within New Zealand (e.g. Cutleria multifida), new records for the New Zealand region (at family, genus and species levels — e.g. Dumontiaceae, Cutleria, Dictyota, Peyssonnelia spp), and new discoveries (e.g. Halymenia sp., Grateloupia sp., Tsengia ...

Ballantine D.L. and Ruiz H. 2010. Two new deepwater Peyssonnelia species, Peyssonnelia iridescens and Peyssonnelia gigaspora (Peyssonneliaceae, Rhodophyta) from Puerto Rico, Caribbean Sea. Phycologia 49: 537–544. DOI: 10.2216/09-88.1 Two new distinctive Peyssonnelia species are described from deepwater habitats in southwestern Puerto Rico. Peyssonnelia iridescens possesses a distinctive bluish iridescent fringe and forms loosely adherent blades up to 6.0 cm across. The crusts possess a Peyssonnelia atropurpurea-type vegetative organization. Tetrasporangia are cut off distally from apical perithallial cells and measure up to 53 µm wide × 135 µm long. Carposporangia measure 25–30 µm in their largest dimension and are formed in elongate nemathecia. Peyssonnelia gigaspora is variously coloured, tan to reddish, with obvious radial striations and reddish spots when living. The crusts are closely appressed to the substratum and normally measure up to 130 µm in thickness, but are occasionally 200 µm thic...

The Peyssonneliaceae Denizot comprises a worldwide group of non-calcified or calcified, crust-forming red algae found in diverse, intertidal to deep subtidal marine habitats. Eight genera have been recognized in the family, with Peyssonnelia Decaisne having the largest number of species. Both comparative morphology and rbcL and nuclear LSU rDNA sequence data support the monophyly of the family and show that it cannot be maintained in the order Gigartinales Schmitz. A new order, Peyssonneliales, is herein proposed to accommodate the Peysonneliaceae, with only two of the genera (i.e., Peyssonnelia and Sonderopelta), and its relationship to the other red algal orders is discussed. We also propose the transfer of one species, Peyssonnelia capensis Montagne to Sonderopelta Womersley & Sinkora.

SUMMARY The vegetative and reproductive morphology of the crustose red alga Peyssonnelia japonica (Segawa) Yoneshigue was re-examined based on the holotype specimen and recent collections from various localities in Japan, including the type locality, and Hawaii. This species is characterized by the following features: thallus with appressed margins, perithallial filaments arising from the entire upper surface of each hypothallial cell (the Peyssonnelia rubra-type), easily separable perithallial filaments in a gelatinous matrix, hypothallial filaments arranged in parallel rows, unicellular rhizoids, hypobasal calcification, gonimoblasts derived mainly from connecting filaments, and spermatangia produced in a series of whorls comprised of one to four paired spermatangia surrounding each central cell (the Peyssonnelia dubyi-type). In addition to these features, the dimensions of the vegetative and reproductive structures of Peyssonnelia boudouresquei Yoneshigue described from Brazil were consistent with those of P. japonica. Molecular phylogenetic analyses using partial 26S rDNA, rbcL, and cox2-3 spacer DNA sequences also supported the monophyly of P. japonica (from 16 localities in Japan and one locality in Hawaii) and P. boudouresquei (from two localities in Brazil). Therefore, P. boudouresquei may be a taxonomic synonym of P. japonica. However, considering the relatively high sequence divergences between the two taxa (2.1–2.5% in partial 26S rDNA, 5.9–6.7% in rbcL, and 5.8–6.7% in cox2-3 spacer), and the relatively limited geographic sampling ranges, we reserve the taxonomic conclusion until further morphological and genetic data of the specimens from other geographic areas connecting Japan and Brazil become available.

The taxonomic distinctiveness of the crustose red algal genus Polystrata Heydrich (Peyssonneliaceae) is confirmed on the basis of morphological and molecular data. The vegetative and reproductive morphology of the type species Polystrata dura Heydrich is newly described. Polystrata thalli are thick multi-layered crusts, each crust of which is composed of a mesothallus, a superior perithallus, and an inferior perithallus. P. dura is characterized by a poorly developed inferior perithallus consisting of single-celled perithallial filaments and each layer of multi-layered crusts being closely adherent to the parental layer. This Polystrata species is identical to Peyssonnelia species, the type genus of the Peyssonneliaceae in the morphology of sexual reproductive organs: a carpogonial branch and an auxiliary cell branch are formed laterally on respective nemathecial filaments; the gonimoblasts are developed from connecting filaments and auxiliary cells; the spermatangia are produced in male and female nemathecia; and the spermatangial filament produces a series of one to four paired spermatangia that form a whorl surrounding each central cell (the Peyssonnelia dubyi-type development). Polystrata fosliei (Weber-van Bosse) Denizot is clearly distinguished from P. dura by an inferior perithallus as well-developed as the superior peri. thallus, and each layer of multi-layered crusts being loosely adherent to the parental layer. In our small subunit rDNA trees of the Peyssonneliaceae, these Polystrata species formed a clade with low to medium supports, although the phylogenetic position of Polystrata was unresolved in this family. Therefore, the thallus structure of Polystrata may be regarded as an important taxonomic character at the genus rank.

The characteristics of Peyssonnelia capensis Montagne (Peyssonneliaceae, Rhodophyta) from Jeju Island were investigated in order to clarify the species entity and re-evaluate taxonomic position. The morphological variations of the Peyssonnelia capensis from Jeju Island were divided into two types, the thin thallus type and the thick thallus type. The thin thallus type is characterized by thin, soft, orbicular, slightly lobed thallus with entire to undulate margin, and compact rhizoids. The thick thallus type has thick and stiff thallus with sinuate margin and scattered rhizoids, and has more branches than the thin thallus type. The basal layer and the epithallium of thin thallus type are similar to those of thick thallus types in their structure. However, the hypothallial cells of the thick thallus type are longer than those of the thin thallus type. The erect filament of thick thallus type has more cells than those of the thin thallus type. Tetrasporangial nemathecia are distinctly protruded. Mature tetrasporangia of this species are divided cruciately into four spores as those of other Peyssonneliaceae. In addition to their morphological and anatomical distinctness between two types, the nucleotide sequence analyses of SSU and ITS2 region make no differences among populations from Jeju and other localities in Korea. Therefore these two morphological variation may not base on genetic variation.

SUMMARY Two species of the crustose red algal genus Peyssonnelia (Gigartinales, Peyssonneliaceae) are reported from Japanese waters for the first time. These species share the following combination of vegetative and reproductive features: thalli with appressed margins, perithallial filaments arising from the whole upper surface of each hypothallial cell (the Peyssonnelia rubra-type anatomy), unicellular rhizoids, hypobasal calcification and spermatangia that are produced in double chains (the Peyssonnelia harveyana-type spermatangial filament). However, they differ obviously from each other in the hypothallus orientation as seen from below, the perithallus structure in relation to the consistency of the crust, the origin of gonimoblasts and the elevation of the nemathecia. Peyssonnelia armorica is characterized by: (i) hypothallial filaments comprising a polyflabellate layer; (ii) easily separable perithallial filaments in a gelatinous matrix; (iii) gonimoblasts originating exclusively from the auxiliary cell; and (iv) semi-immersed (slightly elevated) nemathecia. Peyssonnelia harveyana is characterized by: (i) hypothallial filaments arranged in parallel rows; (ii) closely packed perithallial filaments in a firm matrix; (iii) gonimoblsts originating from both the auxiliary cell and the connecting filament; and (iv) conspicuously elevated nemathecia.

Two highly colourful encrusting red algal species from deep and shallow coral reef habitats in Puerto Rico are reported. Peyssonnelia boergesenii Weber Bosse is characterized by its multicoloured appearance, polyflabellate arrangement of hypothallial cells and multicellular holdfasts. Peyssonnelia flavescens sp. nov. is variably bi- to tri-coloured, with the principal background colour bright yellow to tan. It forms large crusts, to 30 cm in diameter, which are variably thick, measuring 310–640 μm in thickness. The new species differs from other known Peyssonnelia species by cutting off elongate, 12–17 μm long, spermatangial initials that cut off seriate chains of spermatangia distally and by its production of very large tetrasporangia, to 170 μm long.

Vegetative and reproductive features of the red alga Peyssonnelia meridionalis (Peyssonneliaceae, Gigartinales) are reported on the basis of material collected in Hokkaido, Japan. It is characterized vegetatively by tightly appressed margins, the basal layer (hypothallus) consisting of little-branched filaments which are arranged in parallel, the erect perithallial filaments arising from the whole upper surface of each hypothallial cell, and unicellular rhizoids. Gametophytes are monoecious and produce female and male reproductive structures in separate nemathecia that are distinctly (but slightly) elevated. Gonimoblasts issue from the connecting filament that develops from the suprabasal cell of carpogonial branches, which contacts with a fertilized carpogonium by a connecting cell. Spermatangial nemathecia consist entirely of spermatangial filaments, which bear a series of one to four paired spermatangia that form a whorl surrounding each central cell. Tetrasporangia with a one-celled pedicel are terminal on a perithallial filament of distinctly (but slightly) elevated nemathecia and are associated with simple paraphyses.

During a survey of red marine algae from Espirito Santo State, Brazil, five species of Peyssonnelia were collected in the intertidal zone or as drift material: Peyssonnelia armorica (P.Crouan et H....

A new species of the genus Polysiphonia from the Mediterranean Sea is described. It is an ecorticate species, with 4 pericentral cells, showing prostrate axes from which erect axes arise. Rhizoids are formed by pericentral cells in a median position remaining in open connection with them. Erect axes are straight, simple throughout or pseudodichotomous at the base then simple or with one (rarely two-three) orders of branching; trichoblasts and scar cells not observed. Only tetrasporangial plants were found. They show ellipsoid tetrasporangia borne in short straight series, often interrupted by sterile segments. The new species is also characterized by a peculiar habit consisting of prostrate axes, adhering to lower faces of Peyssonnelia spp. by means of rhizoids growing upward, from which erect upright axes perforating thalli of the supporting species arise. A comparison with the related species of Polysiphonia was also carried out.

Photoinhibition of photosynthesis, defined as reversible decrease in the effective photosynthetic quantum yield, was measured in the Mediterranean red alga, Peyssonnelia squamata, using pulse amplitude modulation (PAM) chlorophyll fluorescence and oxygen production on site. This alga is adapted to very low fluence rates of solar radiation and is easily inhibited by exposure to excessive radiation. At high solar angles its photosynthetic capacity is impaired even in its natural habitat, in the protective shade of overhanging rocks. Oxygen production was maximal at 5 m depth and decreased to almost zero at the surface. When exposed at the surface oxygen production ceased within 16 min. The optimal photosynthetic quantum yield, defined as Fv/Fm, was about 0.45 in dark-adapted specimens. After 30 min of exposure to unattenuated solar radiation the (effective, Fv′/Fm′) quantum yield decreased to below 0.1. Removing solar UV (especially UV-B) significantly reduced photoinhibition: the quantum yield of a sample exposed under a UV-B cut-off filter was double that of a sample exposed to full solar radiation after 30 min exposure. Recovery from photoinhibition took several hours and was not complete after prolonged exposure (1.5 h) to direct solar radiation. The degree of photoinhibition depended on the depth at which the thalli were exposed. Recovery from photoinhibition was complete within 2 h except when the algae were exposed at the surface. When measured over the whole day, the effective photosynthetic quantum yield significantly decreased by about 25% from initially high values toward early afternoon and rose again towards evening. The data indicate that this alga is adapted to very low irradiances and is easily inhibited by excessive solar radiation; solar UV contributes substantially to the observed photoinhibition.

Peyssonnelia immersa sp. nov. is described from the British Isles and France. The species has been found intertidally on bedrock and stones and on mobile substrata in the sublittoral. It differs from all previously described species by possessing a unique combination of vegetative and reproductive characters; of particular note is the development of reproductive organs in extensive immersed sori. Terminal cruciate tetrasporangia, occasionally borne on thickened filaments, are surrounded by a complex stratified wall. Carpogonial branches, auxiliary cell branches and spermatangia are accessory in origin and develop among pigmented sterile filaments in the same sori. One or more gonimoblasts arise from the connecting filament after fusion with a series of auxiliary cells and the mature carposporophyte consists of simple or branched chains of 2–5 large carposporangia. In laboratory culture, tetraspores obtained from field material of P. immersa gave rise to crusts similar to field plants. Gametangia and immat...

Studies on the genus Peyssonnelia (Rhodophyceae). III. Peyssonnelia crispata sp. nov. – A new specie of Peyssonnelia (P. crispata) is described from deep waters (44 to 45 m.) off the mediterranean coast of France.

Studies on the genus Peyssonnelia (Rhodophyceae). X. Presence of Peyssonnelia codana (Rosenvinge) Denizot in the Mediterranean.—Peyssonnelia codana (Rosenvinge) Denizot, previously known only from Denmark, is recorded from the vicinity of a thermal power plant outlet (Martigues-Ponteau, Gulf of Fos, France). Mediterranean specimens are described and new details about the morphology of sporangial and sexual nemathecia are given.

The development of the female nemathecium of the genus Ochtodes is followed. Carpogonial, auxiliary cell, and vegetative branches collectively form the nemathecium. The initials of these branches are terminal cells of lateral determinate branches. Structures described by Joly & Ugadim (1966) as carpogonial branches are interpreted as hair cells. The carpogonial branch, four-celled auxiliary cell branches, and post-fertilisation events leading to the formation of the carposporophyte are described for the first time for the genus. Procarpic and non-procarpic assemblages are present in the same plant. The evolutionary and taxonomic significance of the presence of these assemblages is discussed. Based on the structure of the auxiliary cell branch and post-fertilization events leading to the formation of the carposporophyte, the genus Ochtodes appears to be most closely related to Peyssonnelia and Cruoriella of the Peyssonneliaceae.

The present study attempts to determine the factors which induce spores in the genus Peyssonnelia to undergo two different forms of embryogeny. Carpospores and tetraspores of P. squamaria (Gmelin, 1768) Decaisne, 1841 were cultivated, and two types of development noted: the “Dumontia type”, typical of prevalently saxicolous thalli, and the “Naccaria type”, observed in plants growing as emi-endophytes. This is the first time that this phenomenon has been observed in the Peyssonneliaceae.

Studies on the genus Peyssonnelia (Rhodophyceae). I. - Peyssonnelia rosa-marina sp. nov. and Peyssonnelia bornetii sp. nov. – P. rosa marina is distinguished from P. polymorpha (Zanard.) Schmitz in having multicellular rhizoids; the two species are very similar in appearance, but the results show they also differ in several other points. P. bornetii, at a first glance, is a less slender form of P. rubra (Grev.) J. Ag., to whitch it is closely related; it differs from this species mainly by the lack of cystolits.

Researches on the morphogenesis of the genus Peyssonnelia Decaisne. — This paper reports the first result on morphogenetic researches in cultures of 3 species of the genus Peyssonnelia Decne. The development of Peyssonnelia rubra (Grev.) J. Ag. is of «Dumontia type »(CHEMIN, 1937) that one of Peyssonnelia squamaria (Gmelin) Decne. and of Peyssonnelia inamoena Pilger of «Naccaria type». According to our cultures results the morphogenesis of genus Peyssonnelia is of two type. Sample of P. squamaria and P. inamoena are collected in the gulf of Trieste (Nord Adriatic Sea) those of P. cfr. rubra in the Morlaix Bay (English Channel). Taxonomic value of the results are discussed.