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Phymatolithon atlanticum is newly described from France and Northern Ireland (the United Kingdom) using both molecular (rbcL sequence data, concatenated psbA and COI-5P datasets) and morpho-anatomical analyses. The species shows sequence divergences from other Phymatolithon species by 10.7–15.3% in rbcL, 5.1–9.2% in psbA and 9.6–16.8% in COI-5P. Morpho-anatomically, P. atlanticum is encrusting to lumpy, has slightly sunken female conceptacles with raised rims, lacks buried conceptacles, has five to six rosette cells surrounding tetra/bisporangial conceptacle pores, and has tetra/bisporangial conceptacle roofs that are pitted with depressions as a result of the disintegration of rosette cells. This latter feature is what currently separates the species morpho-anatomically from all other species of Phymatolithon. The tetra/bisporangial conceptacle of P. atlanticum closely resembles those of Lithothamnion crispatum and Leptophytum bornetii and may well represent additional examples of convergent evolution in the non-geniculate coralline algae.

The future of coral reef ecosystems is under threat because vital reef-accreting species such as coralline algae are highly susceptible to ocean acidification. Although ocean acidification is known to reduce coralline algal growth rates, its direct effects on the development of coralline algal reproductive structures (conceptacles) is largely unknown. Furthermore, the long-term, multi-generational response of coralline algae to ocean acidification is extremely understudied. Here, we investigate how mean pH, pH variability and the pH regime experienced in their natural habitat affect coralline algal conceptacle abundance and size across six generations of exposure. We show that second-generation coralline algae exposed to ocean acidification treatments had conceptacle abundances 60% lower than those kept in present-day conditions, suggesting that conceptacle development is initially highly sensitive to ocean acidification. However, this negative effect of ocean acidification on conceptacle abundance disappears after three generations of exposure. Moreover, we show that this transgenerational acclimation of conceptacle development is not facilitated by a trade-off with reduced investment in growth, as higher conceptacle abundances are associated with crusts with faster growth rates. These results indicate that the potential reproductive output of coralline algae may be sustained under future ocean acidification.

Molecular phylogenetic analyses discovered an unexpected biodiversity of coralline algae in modern oceans. This species richness is unlikely to be an exclusive characteristic of recent ecosystems. With the aim to investigate fossil coralline biodiversity, a large dataset of western Mediterranean Miocene specimens, previously identified as Spongites fruticulosus (and synonymized taxa), have been re-vised based on the current taxonomic framework. The analysis recognized two distinct groups. The first group includes the specimens fitting within the current description of S. fruticulosus. The second group consists of Chamberlainium pentagonum comb. nov., the first fossil representative of the genus. This species has been separated from S. fruticulosus on the basis of its smaller conceptacles and its thinner conceptacle roof. The very same characters have been highlighted by modern molecular phylogenetic analyses for separating Chamberlainium from Spongites. Chamberlainium pentagonum, simi-larly to the fossil specimens of Spongites fruticulosus, occurs in most of the investigated area and the two species coexist in several localities, indicating a similar and broad ecological tolerance for both taxa. These results suggest that Miocene coralline algal biodiversity is probably underestimated and prove the convenience of using large datasets for the study of fossil coralline algae.

The morphology, anatomy and reproduction (tetra/bisporic and male) of Lithothamnion japonicum Foslie was studied, using holotype material and materials collected from Korea. Lithothamnion japonicum is characterized based on the presence of encrusting, warty to fruticose thallus, branched or unbranched short and cylindrical protuberances, conical shaped spermatangial conceptacles, branched (dendroid) spermatangial systems formed on floor, walls, and roof of conceptacle chamber, cylindrical shaped spermatangial conceptacle canal, 9-10 cell layered spermatangial conceptacle roof, raised tetra/bisporangial conceptacles without rims, flattened tetra/ bisporangial conceptacle pore plate, 16-50 pores on each pore plate, 6-8 rosette cells surrounded by each pore, pore canal lining filaments composed of tetra/bisporangial conceptacle roof, and buried senescent tetra/bisporangial conceptacles completely infilled with relatively large and irregularly arranged calcified sterile cells. In this study, we report a new record of Lithothamnion japonicum from Korean coasts.

Adeylithon gen. nov. with one species, A. bosencei sp. nov., belonging to the subfamily Hydrolithoideae is described from Pacific coral reefs based on psbA sequences and morpho-anatomy. In contrast with Hydrolithon, A. bosencei showed layers of large polygonal "cells," which resulted from extensive lateral fusions of perithallial cells, interspersed among layers of vegetative cells. This anatomical feature is shared with the fossil Aethesolithon, but lacking DNA sequences from the fossils and the fragmentary nature of Aethesolithon type material, we cannot ascertain if Adeylithon and Aethesolithon are congeneric. Morpho-anatomical features of A. bosencei were generally congruent with diagnostic features of the subfamily Hydrolithoideae: (i) outline of cell filaments entirely lost in large portions due to pervasive and extensive cell fusions, (ii) trichocytes not arranged in tightly packed horizontal fields, (iii) basal layer without palisade cells, and (iv) cells lining the canal pore oriented more or less perpendicular to roof surface and not protruding into the canal. However, it showed a predominant monomerous thallus organization and trichocytes were disposed in large pustulate, horizontal fields, although they were not tightly packed and did not become distinctly buried in the thallus. Only mature tetrasporangial conceptacles were observed, therefore the type of conceptacle roof formation remained undetermined. Adeylithon bosencei occurs on shallow coral reefs, in Australia, Papua New Guinea, and South Pacific islands (Fiji, Vanuatu). Fossil Aethesolithon is considered an important component of shallow coral reefs since the Miocene; fossil records showed a broad Indo-Pacific distribution, but a long-term process of range contraction in the last 2.6 million years, resulting in an overlap with the distribution of the extant Adeylithon. While the congeneric nature of extant and fossil taxa remained uncertain, similarities in morpho-anatomy, habitat, and distribution may indicate that both taxa likely shared a common ancestor.

A new, more complete, five-marker (SSU, LSU, psbA, COI, 23S) molecular phylogeny of the family Corallinaceae, order Corallinales, shows a paraphyletic grouping of seven well-supported monophyletic clades. The taxonomic implications included the amendment of two subfamilies, Neogoniolithoideae and Metagoniolithoideae, and the rejection of Porolithoideae as an independent subfamily. Metagoniolithoideae contained Harveylithon gen. nov., with H. rupestre comb. nov. as the generitype, and H. canariense stat. nov., H. munitum comb. nov., and H. samoënse comb. nov. Spongites and Pneophyllum belonged to separate clades. The subfamily Neogoniolithoideae included the generitype of Spongites, S. fruticulosus, for which an epitype was designated. Pneophyllum requires reassesment. The generitype of Hydrolithon, H. reinboldii, was a younger heterotypic synonym of H. boergesenii. The evolutionary novelty of the subfamilies Hydrolithoideae, Metagoniolithoideae, and Lithophylloideae was the development of tetra/bisporangial conceptacle roofs by filaments surrounding and interspersed among the sporangial initials.

Du, W., Wang, X.L., Komiya, T., Zhao, R. & Wang, Y., April 2016. Dendroid multicellular thallophytes preserved in a Neoproterozoic black phosphorite in southern China. Alcheringa 40, xxx–xxx. ISSN 0311-5518.A new form of dendroid multicellular thallophyte is documented in the Ediacaran Doushantuo phosphorite at Weng’an, Guizhou Province, southern China. The dendroid thallophytes have variable forms, possibly owing to heteromorphic variation. Many lateral branches extend from the upper portions of the main axes; the lateral branches bear terminal vegetative vesicles, reproductive vesicles, monosporangium-like discoidal vesicles and urn-shaped pseudoparenchymatous structures. The vegetative vesicles give rise to clavate pseudoparenchymatous structures, characterized by differentiation of the thallus medulla/cortex, which might represent an early stage of thallus development. An oogamous conceptacle arising from one carpogonial vesicle forms a highly specialized goblet-shaped conceptacle. The discovery of th...

Summary A new canker disease of Salix alba and Populus alba has been observed in Xinjiang, China. Black circular spots on dead branches and stems are the symptoms of the disease. Sixty-seven isolates recovered from Salix matsudana, S. alba and Populus alba were identified as Cryptosphaeria pullmanensis based on morphological features and multigene phylogeny. Pathogenicity tests were performed on S. alba and P. alba stems using the C. pullmanensis isolates. Cankers on and Cryptosphaeria pullmanensis of C. pullmanensis from the stems fulfilled Koch's postulates and confirmed C. pullmanensis as the causal agent of the canker disease. C. pullmanensis is characterized by its yellow stromatic tissue surrounded by a black conceptacle with regularly arranged multiple locules sharing common walls and hyaline, allantoid, aseptate conidia (mean size 7.42 × 1.72 μm). This is the first report of C. pullmanensis causing Cryptosphaeria canker in China, and S. alba and P. alba are new host records for C. pullmanensis.

New empirical and quantitative data in the study of calcium carbonate biomineralization and an expanded coralline psbA framework for phylomineralogy are provided for crustose coralline red algae. Scanning electron microscopy (SEM) and energy dispersive spectrometry (SEM-EDS) pinpointed the exact location of calcium carbonate crystals within overgrown reproductive conceptacles in rhodolith-forming Lithothamnion species from the Gulf of Mexico and Pacific Panama. SEM-EDS and X-ray diffraction (XRD) analysis confirmed the elemental composition of these calcium carbonate crystals to be aragonite. After spore release, reproductive conceptacles apparently became overgrown by new vegetative growth, a strategy that may aid in sealing the empty conceptacle chamber, hence influencing the chemistry of the microenvironment and in turn promoting aragonite crystal growth. The possible relevance of various types of calcium carbonate polymorphs present in the complex internal structure and skeleton of crustose corallines is discussed. This is the first study to link SEM, SEM-EDS, XRD, Microtomography and X-ray microscopy data of aragonite infill in coralline algae with phylomineralogy. The study contributes to the growing body of literature characterizing and speculating about how the relative abundances of carbonate biominerals in corallines may vary in response to changes in atmospheric pCO2 , ocean acidification, and global warming.

The diagnosis of the order Sporolithales is currently restricted to tetrasporangial anatomy. Until recently, there were few reports about gametangial, and more specifically carposporangial material for the Sporolithales. This study provides the first detailed observations of the anatomy of the mature carposporophyte phase from three species of Sporolithales commonly found in rhodolith beds from Brazil: Sporolithon episporum, S. ptychoides, and Sporolithon sp. Using these observations, along with previously published descriptions and illustrations from other representative species in the order, a comparison was made with the other three orders (Corallinales, Hapalidiales, and Rhodogorgonales) of the Corallinophycidae. We amend the diagnosis of the order Sporolithales to include the anatomy of the mature carposporophyte as follows: carposporangial conceptacles that lack a central fusion cell, but instead with numerous, short, one to two-celled, filaments that bear oblong terminal carposporangia that are distributed across the conceptacle chamber floor and walls.

A multi-gene (SSU, LSU, psbA, and COI) molecular phylogeny of the family Corallinaceae (excluding the subfamilies Lithophylloideae and Corallinoideae) showed a paraphyletic grouping of six monophyletic clades. Pneophyllum and Spongites were reassessed and recircumscribed using DNA sequence data integrated with morpho-anatomical comparisons of type material and recently collected specimens. We propose Chamberlainoideae subfam. nov., including the type genus Chamberlainium gen. nov., with C. tumidum comb. nov. as the generitype, and Pneophyllum. Chamberlainium is established to include several taxa previously ascribed to Spongites, the generitype of which currently resides in Neogoniolithoideae. Additionally we propose two new genera, Dawsoniolithon gen. nov. (Metagoniolithoideae), with D. conicum comb. nov. as the generitype and Parvicellularium gen. nov. (subfamily incertae sedis), with P. leonardi sp. nov. as the generitype. Chamberlainoideae has no diagnostic morpho-anatomical features that enable one to assign specimens to it without DNA sequence data, and it is the first subfamily to possess both Type 1 (Chamberlainium) and Type 2 (Pneophyllum) tetra/bisporangial conceptacle roof development. Two characters distinguish Chamberlainium from Spongites: tetra/biasporangial conceptacle chamber diameter (300 μm in Chamberlainium vs.300 μm in Spongites) and tetra/bisporangial conceptacle roof thickness (8 cells in Chamberlainium vs.8 cells in Spongites). Two characters also distinguish Pneophyllum from Dawsoniolithon: tetra/bisporangial conceptacle roof thickness (8 cells in Pneophyllum vs.8 cells in Dawsoniolithon) and thallus construction (dimerous in Pneophyllum vs. monomerous in Dawsoniolithon).

(Spongites yendoi (Foslie) Chamberlain (Corallinales, Rhodophyta) on the coast of Bahia, Brazil). We report the first occurrence of S. yendoi (Foslie) Chamberlain on the northeastern coast of Brazil, and the second record of the species on the Brazilian coast. We collected specimens on two beaches in the cities of Salvador and Camacari, Bahia, Brazil. The species were identified by the presence of monomerous thallus construction, trichocytes arranged in horizontal fields, central columella, and tetrasporangial conceptacle morphometry. Our record extends the distribution range of this species into Brazilian waters.

Fossil specimens of two semi-endophytic species of Lithophyllum, L. kenjikonishii sp. nov. and L. cuneatum (Corallinaceae, Rhodophyta), were discovered in thin sections of ocean floor cores of the last deglacial period (c. 20,000–10,000 years before present) obtained from Tahiti, French Polynesia, during Expedition 310 of the Integrated Ocean Drilling Program. Detailed morphological–anatomical accounts of both species are provided, and their placement in Lithophyllum and the subfamily Lithophylloideae is discussed in relation to recent classification proposals. Lithophyllum kenjikonishii, recorded only from fossil thalli, and L. cuneatum, known from fossil and nonfossil thalli, are readily distinguished in tetrasporangial conceptacle pore canal anatomy and on differences in spermatangial conceptacle chamber anatomy. Both species are semi-endophytic in Hydrolithon onkodes, another species of Corallinaceae. Taphonomic signatures evident in thin sections suggest that the occurrence of L. kenjikonishii, L. cu...

Summary The nongeniculate species Neogoniolithon brassica-florida (Harvey) Setchell et Mason is circumscribed as a polymorphic species with various gross morphologies due to it being synonymized with several previous species. However, small subunit rDNA and cox1 analyses showed that N. brassica-florida was polyphyletic, and strongly imply that crustose species lacking any protuberances such as Neogoniolithon fosliei (Heydrich) Setchell et Mason and species with protuberances or branches such as N. brassica-florida and N. frutescens (Foslie) Setchell et Mason should be treated as genetically different groups (species). Therefore, we propose the resurrection of N. frutescens. We also confirmed that N. trichotomum was distinguished from N. frutescens by slender uniform diameter branches, a conceptacle with a prominent ostiole, and large cox1 interspecific sequence differences. Male and female reproductive structures of N. trichotomum were illustrated for the first time. Neogoniolithon fosliei, was divided into three clades, each of which was recognized as a species complex based on interspecific level sequence differences within clade and morphological differences. Therefore, we treated the clade most similar to N. fosliei as N. fosliei complex (Clade B), and the other clades as respective complexes of N. cf. fosliei with yellow conceptacles (Clade A) or N. cf. fosliei with large conceptacles (Clade C). Of two species complexes (Clade A and B) were morphologically consistent with two entities of N. fosliei previously reported in the Ryukyu Islands, Japan, which is supported by their niche partitioning. DNA barcoding research of nongeniculate corallines can promote the finding of more reliable taxonomic characters and the understanding of their biological aspects.

This paper provides a description of the articulated species of the Tribe Janieae (Corallinales, Rhodophyta) in the Pacific coast of Baja California and Gulf of California, Mexico. This taxonomic report is based on newly collected data in the study area and material currently housed at several herbaria. As a result of the present study, the record of the tribe Janieae is represented at the Pacific coast of Mexico for one genus: Jania J. V. Lamouroux with nine species. Morphological, reproductive and anatomical descriptions are provided in detail. In addition, keys for determination are included, as well as habitat, nomenclature, comparisons with other species and information on distribution. Instead of eleven species of Jania currently recorded for the study area, we recognize only nine. Jania verrucosa is restricted to the occidental coast from the Peninsula of Baja California. The remainder of the species commonly occurs in the Gulf of California and the Pacific coast of Baja California’s Peninsula. On the other hand, the gametangial thalli of J. adhaerens and tetrasporangial conceptacle in J. longiarthra are reported for the first time in Mexico.

The temporal dimension of the most recent Corallinaceae (order Corallinales) phylogeny was presented here, based on first occurrence time estimates from the fossil record. Calibration of the molecular clock of the genetic marker SSU entailed a separation of Corallinales from Hapalidiales in the Albian (Early Cretaceous ~105 mya). Neither the calibration nor the fossil record resolved the succession of appearance of the first three emerging subfamilies: Mastophoroideae, Corallinoideae, and Neogoniolithoideae. The development of the tetra/bisporangial conceptacle roofs by filaments surrounding and interspersed among the sporangial initials was an evolutionary novelty emerging at the Cretaceous-Paleogene boundary (~66 mya). This novelty was shared by the subfamilies Hydrolithoideae, Metagoniolithoideae, and Lithophylloideae, which diverged in the early Paleogene. Subclades within the Metagoniolithoideae and Lithophylloideae diversified in the late Oligocene-middle Miocene (~28-12 mya). The most common reef corallinaceans (Hydrolithon, Porolithon, Harveylithon, "Pneophyllum" conicum, and subclades within Lithophylloideae) appeared in this interval in the Indo-Australian Archipelago.

The examination of fossil Lithothamnion specimens ranging in age from the Early Miocene to the Pleistocene revealed the occurrence of multiporate conceptacle chambers pitted with depressions. This is the diagnostic feature of Lithothamnion crispatum, a cosmopolitan hapalidiacean with a wide depth range in modern oceans. The comparison of the microscopic anatomy of both the fossil and mo-dern L. crispatum confirmed that they are conspecific. Therefore, this species has a long stratigraphic distribution starting at least 20 My ago, without significant morphological changes in either reproductive or vegetative anatomy.

Sporolithon ptychoides Heydrich (Sporolithaceae, Sporolithales), the type species of the genus Sporolithon, is newly reported for Thai waters based on specimens collected from the Gulf of Thailand and the Andaman Sea. A detailed morphological and anatomical account is provided, including comparisons with published data of S. ptychoides and its related species. Epithallial cells are flared. Cells of adjacent filaments connect laterally mostly by secondary pit connections. Tetrasporangia are grouped in sori that occur in patches over the thallus surface. Sori are buried in distinct rows in the thallus. Details of male, female and carposporangial conceptacles of S. ptychoides are described for the first time. Gametangial thalli are monoecious with spermatangia and carposporangia born in uniporate conceptacles. Dendroid spermatangial branches occur on the floor, walls and roof of the male conceptacle chamber. Carpogonial branch consists of a hypogenous cell and a carpogonium. Central fusion cell is a...

Maneveldt G.W. and van der Merwe E. 2012. Heydrichia cerasina sp. nov. (Sporolithales, Corallinophycidae, Rhodophyta) from the southernmost tip of Africa. Phycologia 51: 11–21. DOI: 10.2216/11-05.1 A new species of Heydrichia (Sporolithales), Heydrichia cerasina sp. nov., is described, found only on pebbles in the low intertidal zone along a 10 km stretch of the South African south coast from Cape Agulhas to Struisbaai. The species is characterized by the following suite of features that distinguish it from the other two species of Heydrichia found in South Africa: (1) unusual cherry-red colour when freshly collected; (2) uniformly warty growth form; (3) relatively thin crust (up to 1400 µm thick); (4) tetra/bisporangial sori comprised of mostly single sporangial chambers; and (5) unbranched spermatangial structures distributed on the floor, walls, and roof of the mature male conceptacle. The species appears to be most closely related to Heydrichia homalopasta from Australia. This study has affirmed that ...

Sargassum vulgare C. Agardh shows androgynous receptacles, each bearing on an average 12 unisexual conceptacles which open outside by ostiole, and wherein gametangia (antheridia or oogonia) lie interspersed with paraphyses. Since out-put of eggs is extremely low, 4 - 6 per female conceptacle, Sargassum sp. ensures its survival under all eco-physiological conditions. The released oogonium is “wrapped” in sulphated polysaccharide-rich wall layer known to provide protection against desiccation. Oogonia after being “extruded” out of ostiole, are “incubated” on receptacle, where they grow into eggs that are easily contacted by spermatozoids. Gamete release is synchronous and almost simultaneous ensuring high rates of fertilization. The release occurs on days falling near a full moon or new moon, during low tides when conceptacles lie exposed. Gamete release occurs first from upper conceptacles, which “house” mature gametangia while lower ones are still developing. This results in gamete release over an extended period of time. The zygote dispersal and propagule recruitment also show adaptations selectively advantageous for the alga.

Corallines or coralline algae are carbonate secreting and strongly calcified red algae of the order Corallinales of division Rhodophyta. Architecturally, the corallines have two groups, the nongeniculate and geniculate coralline forms. Corallines are used as a potential tool for paleoecology, paleoenvironments and paleobathymetry. Coralline algae are builder of porous and permeable carbonate reservoir rocks for hydrocarbon and reefs rich in hydrocarbon. The old approach, ca. prior to 1977, of taxonomy of fossil coralline genera has been replaced by the modern approach that established during the last decade using certain distinguishing features such as arrangement of basal filaments, cell fusions, conceptacle perforations and orientation of filaments around conceptacles of living corallines. The earliest confirmed fossil record of coralline algae is from the Hauterivian (Early Cretaceous) and from the Hauterivian to the Pleistocene 9 nongeniculate coralline genera, namely Distichoplax, Lithophyllum, Lithoporella, Lithothamnion, Mesophyllum, Neogoniolithon, Phymatolithon, Spongites and Sporolithon and 7 geniculate genera, viz. Amphiroa, Arthrocardia, Calliarthron, Corallina, Jania, Metagoniolithon and Subterraniphyllum having different stratigraphic ranges are unequivocally known as fossils. After 1977, we do not have a comprehensive publication giving the generic distinguishing characteristics and stratigraphic ranges of both nongeniculate and geniculate corallines. The present paper gives an update of distinguishing characteristics of fossil coralline algal genera and their stratigraphic ranges.

Mesophyllum sphaericum sp. nov. is described based on spherical maerl individuals (up to 10 cm) collected in a shallow subtidal maerl bed in Galicia (NW Spain). The thalli of these specimens are radially organized, composed of arching tiers of compact medullary filaments. Epithallial cells have flattened to rounded outermost walls, and they occur in a single layer. Subepithallial initials are as long as, or longer than the daughter cells that subtend them. Cell fusions are abundant. Multiporate asexual conceptacles are protruding, mound-like with a flattened pore plate, lacking a peripheral raised rim. Filaments lining the pore canal and the conceptacle roof are composed of five to six cells with straight elongate and narrow cells at their base. Carposporangial conceptacles are uniporate, protruding, and conical. Spermatangial conceptacles were not observed. Molecular results placed M. sphaericum near to M. erubescens, but M. sphaericum is anatomically close to M. canariense. The examination of the holotype and herbarium specimens of M. canariense indicated that both species have pore canal filaments with elongate basal cells, but they differ in number of cells (five to six in M. sphaericum vs. four in M. canariense). Based on the character of pore canal filaments, M. canariense shows similarities with M. erubescens (three to five celled). The outermost walls of epithallial cells of M. canariense are flared compared to the round to flattened ones of M. erubescens, the latter being widely accepted for the genus Mesophyllum. The addition of M. sphaericum as new maerl-forming species suggests that European maerl beds are more biodiverse than previously understood.

Growth and calcium carbonate deposition rates of the coralline alga Calliarthron cheilosporioides Manza were quantified by monitoring fronds in the intertidal zone that had been chemically labeled with the nontoxic fluorescent brightener Calcofluor white. This vital stain effectively labeled apical meristems of coralline thalli in the field: fronds exposed for only 5 min had detectable chemical marks at least 1.5 years later. By distinguishing portions of thalli that developed before and after exposure, this methodology permitted accurate measurement of growth and calcium carbonate deposition at each meristem. In Calliarthron, meristematic activity declined with increasing frond size. However, because growing fronds dichotomize, the total number of meristems and the deposition rate of new calcified tissue both increased with frond size. Growth rates reported here suggest that large fronds may not be as old as previously estimated. The Calcofluor white method may improve demographic studies of corallines by resolving growth and age of fronds in the field and may facilitate studies of climate change on calcium carbonate deposition in these ecologically important, calcifying algae.

The presence of banding in the skeleton of coralline algae has been reported in many species, primarily from temperate and polar regions. Similar to tree rings, skeletal banding can provide information on growth rate, age, and longevity; as well as records of past environmental conditions and the coralline alga’s growth responses to such changes. The aim of this study was to explore the presence and characterise the nature of banding in the tropical coralline alga Porolithon onkodes, an abundant and key reef-building species on the Great Barrier Reef (GBR) Australia, and the Indo-Pacific in general. To achieve this we employed various methods including X-ray diffraction (XRD) to determine seasonal mol% magnesium (Mg), mineralogy mapping to investigate changes in dominant mineral phases, scanning electron microscopy–electron dispersive spectroscopy (SEM-EDS), and micro-computed tomography (micro-CT) scanning to examine changes in cell size and density banding, and UV light to examine reproductive (conceptacle) banding. Seasonal variation in the Mg content of the skeleton did occur and followed previously recorded variations with the highest mol% MgCO3 in summer and lowest in winter, confirming the positive relationship between seawater temperature and mol% MgCO3. Rows of conceptacles viewed under UV light provided easily distinguishable bands that could be used to measure vertical growth rate (1.4 mm year-1) and age of the organism. Micro-CT scanning showed obvious banding patterns in relation to skeletal density, and mineralogical mapping revealed patterns of banding created by changes in Mg content. Thus, we present new evidence for seasonal banding patterns in the tropical coralline alga P. onkodes. This banding in the P. onkodes skeleton can provide valuable information into the present and past life history of this important reef-building species, and is essential to assess and predict the response of these organisms to future climate and environmental changes.

Harvey A.S., Woelkerling W.J. and Millar A.J.K. 2009. The genus Amphiroa (Lithophylloideae, Corallinaceae, Rhodophyta) from the temperate coasts of the Australian continent, including the newly described A. klochkovana. Phycologia 48: 258–290. DOI: 10.2216/08-84.1 Studies of Amphiroa (Lithophylloideae, Corallinaceae, Rhodophyta) from the temperate coasts of Australia provide new evidence that differences in tetrasporangial conceptacle pore canal anatomy are diagnostically significant in delimiting species within the genus. Differences in overall morphology and genicular anatomy are also reliable for delimiting species. These data are supported by examination of relevant type specimens. Four species occur in temperate Australian waters. Three (Amphiroa anceps, Amphira beauvoisii, and the newly described Amphiroa klochkovana) occur in southeastern Australia, and three (A. anceps, A. beauvoisii, and Amphiroa gracilis) occur in southern and southwestern Australia. Comparisons of A. beauvoisii and A. ...

Villas-Boas A.B., Riosmena-Rodriguez R., Amado-Filho G.M., Maneveldt G.W. and de O. Figueiredo M.A. 2009. Rhodolith-forming species of Lithophyllum (Corallinales; Rhodophyta) from Espirito Santo State, Brazil, including the description of L. depressum sp. nov. Phycologia 48: 237–248. DOI: 10.2216/08-35.1. The taxonomy of the rhodolith-forming species of Lithophyllum (Corallinales, Rhodophyta) found from Espirito Santo State, Brazil, were evaluated based on extensive subtidal sampling. A comparative analysis of the Brazilian material with recently described species lead us to conclude that three known species (Lithophyllum corallinae, L. johansenii, L. stictaeforme) and one species new to science (Lithophyllum depressum Villas-Boas, Figueiredo & Riosmena-Rodriguez) are present in the area. All four species can be distinguished primarily by their tetrasporangial conceptacle roof anatomy. This study has shown that Brazilian rhodolith beds are comparatively more diverse in number of Lithophyllum spec...

Based on literature, the genus Lithophyllum was represented in the whole Indian Ocean by 14 taxa, mostly in need of revision in a modern context. Molecular analyses integrated with morpho-anatomical comparisons between the recently revised type material of Lithophyllum kotschyanum Unger, and the related infraspecific taxa, lead to a resumption of L. affine , L. kaiseri , and L. subreduncum, and the description of L. socotraense sp. nov. , L. yemenense sp. nov. , and L. subplicatum comb. et stat. nov. Detailed accounts are provided for each species, including keys, along with information on synonymy, examined collections, distribution, habitat as well as sequence data of the 5’ end of the LSU from the type specimens. The anatomical features of the tetrasporangial conceptacle that were considered collectively diagnostic for species identification are: the mean diameter of the tetrasporangial conceptacles, the length of the pore-canal in the tetrasporangial conceptacles (with the number of cells in roof filaments), the occurrence of a depression at the top of the conceptacle roof in relation to the pore opening, and the number of cells from the floor of the tetrasporangial conceptacle chamber to the thallus surface. This study provides evidence of a previously unsuspected diversity within the Red Sea and NW Indian Ocean species of Lithophyllum.

Leptophytum Adey (in Hydrobiologia 28: 323. 1966) was originally established to accommodate two widely distributed North Atlantic-Arctic species; viz. its type Leptophytum laeve (Stromfelt) Adey and Leptophytum foecundum (Kjellman) Adey. Subsequent studies have added to the genus a total of 15 species from temperate regions in both the Southern and Northern Hemispheres (Adey in Kgl. Norske Vidensk. Selsk. Skr. 1: 1-46. 1970; Zaneveld & Sanford in Blumea 26: 205-231. 1980; Steneck & Paine in Phycologia 25: 221-240. 1986; Chamberlain in Br. Phycol J. 25: 179-199. 1990; Chamberlain & Keats in Phycologia 33: 111-133. 1994). Woelkerling (The Coralline Red Algae: 217. 1988) treated Leptophytum as being of uncertain status because the whereabouts of the type material of Leptophytum laeve (= Lithophyllum laeve Stromfelt) was unknown. Dilwel & Wegeberg (in Phycologia 35: 470-483. 1996) reported the discovery by W. J. Woelkerling of the holotype of Stromfelt's Lithophyllum laeve in the Swedish Museum of Natural History in Stockholm (S), and after a study concluded that this element along with the original description of Str6mfelt (l.c.) were inadequate to define the identity of the species. Therefore, these authors selected an epitype from new material collected at the type locality Eyrarbakki (South Iceland). Unfortunately, the epitype selected and described by Diiwel & Wegeberg shows key characteristics of the lectotype of Phymatolithon lenormandii (Areschoug) Adey, rendering Leptophytum laeve and Leptophytum junior synonyms of Phymatolithon lenormandii and Phymatolithon Foslie, respectively. We have recently re-examined the holotype of Lithophyllum laeve Str6mfelt and shown that this element is in agreement with the protologue, matching not the selected epitype but all later descriptions of Leptophytum laeve as circumscribed in the literature of the 20th century (Adey & al. in Eur. J. Phycol. 36: 191-203. 2001) (see Table 1). A distinctive statement in the protologue, that the sporangia of Lithophyllum laeve Str6mfelt were twice as big as those of Phymatolithon lenormandii, is a characteristic definitively present in the holotype and clearly distinguishes these two species. Multiporate conceptacle roofs are also present in the holotype, and these numerically fall in the middle of the extensively described size and sporangial number (pore) range for Leptophytum laeve, at roughly twice the dimensions and pores of Phymatolithon lenormandii, and well beyond the maximum size range known for the latter species. Additionally, pore cells of multiporate conceptacles of the holotype are specialized and in agreement with those described for this species and not for Phymatolithon lenormandii (Adey & al. l.c.). The epitypification of Str6mfelt's Lithophyllum laeve by Dtiwel & Wegeberg has resulted in this name being presently typified by two heterogeneous elements, i.e., the holotype and the epitype, each apparently belonging to a different species and genus. Only the holotype is in agreement with the protologue, and since only this element provides key characteristics that unequivocally refer to our understanding of Lithophyllum laeve Stromfelt, the selected epitype by Diiwel & Wegeberg is both unwarranted and in serious conflict with the protologue. Nevertheless, the epitype cannot just be rejected, as

The development of male gametes (spermacia) in the red alga Gracilaria verrucosa has been studied using methods of transmission electron microscopy. Early spermatangia located along the wall of the conceptacle show an elongated shape in the thin sections. In the central part of the electron-dense cytoplasm of these cells there is a nucleus; numerous fibrous vesicles are arranged in the periphery. During the process of differentiation, the spermatangia become more rounded in shape and a large spermatangial vesicle is developed. The subsequent development of spermatium is accompanied by polarization of the spermatangium and the subsequent excretion of the spermatangial vesicle. The spermatia are oval cells containing a nucleus and fibrous vesicles. The process of differentiation of male gametes in G. verrucosa does not differ from that in five species of the genus Gracilaria, where it has already been studied. However, any conclusions about the degree of similarity between the spermatia in all the studied species can be made only after a detailed comparative analysis of the ultrastructural characteristics of these gametes.

The major diagnostic features for erecting the red algal subfamily Choreonematoideae (Corallinales) were a combination of 1) absence of both cell fusions and secondary pit connections, 2) conceptacle roof and wall comprised of a single cell layer, and 3) presence of tetrasporangial pore plugs within a uniporate conceptacle in the monotypic taxon Choreonema thuretii (Bornet) Schmitz. Because this alga is a parasite, the absence of secondary cell connections is most likely an adaptation to a reduced thallus. This study shows that all conceptacles are not composed of a file of cells but rather a single layer of epithallial cells that are underlain by a thick layer of calcified acellular material; both epithallial cells and the calcified layer are produced by peripheral sterile cells. Although the outermost tetrasporangial pore canal is uniporate, there is a calcified acellular multiporate plate recessed just below the rim. The plate is produced by interspersed sterile cells and is continuous with the calcified layer supporting the conceptacle. These unique structures are likely due to parasitism rather than to the ancestral state. Based on these results and a reexamination of published micrographs depicting lenticular cells in Austrolithon intumescens Harvey et Woelkerling, we propose that both subfamily Choreonematoideae and Austrolithoideae are closely allied with subfamily Melobesioideae. This distant relationship to its host (Corallinoideae) plus a combination of unique conceptacle and unusual type of parasitism indicates that C. thuretii is an alloparasite and that it is likely the most ancient red algal parasite studied to date.

A study was carried out to determine the status and disposition of Corallinaceae recorded from the Ross Sea (Antarctica), viz. Clathromorphum lemoineanum, Leptophytum coulmanicum, L. laeve and L. foecundum. A re-examination of the type of Lithothamnion coulmanicum (basionym of Leptophytum coulmanicum) showed that it is referable to the genus Phymatolithon because it possesses epithallial cells whose outermost walls are rounded to flattened and meristem cells that are as short as or shorter than their immediate inward derivatives. Such characters were also evident in specimens from McMurdo Sound. Moreover, because all the specimens studied had a conceptacle chamber roof c. 300 μm in diameter, a thallus thickness of up to 1 mm, and buried old conceptacles, they are conspecific with P. foecundum. Studies of specimens from Terra Nova Bay identified as C. lemoineanum and of specimens from Franklin Island identified as L. laeve showed that they should all be referred to P. foecundum. Furthermore, judging by the description and illustrations given by Zaneveld & Sanford [Blumea 26: 205-231 (1980)], records of P. foecundum (as L. foecundum) from Cape Hallett and Moubray Bay can be confirmed. Therefore, P. foecundum is the only member of Corallinaceae confirmed to occur in the Ross Sea (Antarctica).

Family Hapalidiaceae is represented in the Atlantic coast of Mexico by three genera and five species. Lithothamnion sejunctum is a new record for Mexico and represents the third record since it was first described and L. crispatum is recorded for the first time for North America Continent. L. crispatum and L. occidentale are developing as maerl in the subtidal zone to 50 m depth. Melobesia membranacea has the widest distribution interval in the study area. Mesophyllum mesomorphum is a species which it has few records in the study area. Detailed accounts are provided for each species along with information on synonymy, collections examined, distribution, and habitat. Qualitative characters associated with tetrasporangial / bisporangial conceptacle roof morphology and anatomy have provided a reliable basis for delimiting the Atlantic Mexican species of Hapalidiaceae.

Here, we describe the development of sporangial and gametangial conceptacles for Amphiroa beauvoisii and A. vanbosseae; sporangial conceptacles only for A. misakiensis; and gametangial conceptacles only for A. cryptarthrodia and A. rigida. The descriptions are based on the observation of histological preparations obtained from 112 specimens collected from the Gulf of California, in Mexico, and the Azores archipelago of Portugal. Information on the development of the sporangial conceptacle pore and conceptacle senescence is here described and illustrated for the first time. Four development patterns were observed: two for sporangial conceptacles; one for spermatangial conceptacles; and one for carposporangial conceptacles. The phases of development of the sporangial conceptacle were found to be useful in delimiting species within the genus. Based on the sporangium location on the cavity floor and the pore canal anatomy, the species A. beauvoisii, A. misakiensis and A. vanbosseae can be distinguished from each other.

Receptacles of Fucus vesiculosus L. were examined using cryoscanning electron microscopy of rapidly frozen, hydrated tissue to avoid extraction and collapse of the extracellular matrix (ECM) and provide new structural information. The pore of the conceptacle was occluded by the tightly appressed tips of the paraphyses. These were embedded in copious ECM within the conceptacle. The ECM inside the conceptacle and in the medulla differed markedly in texture and with respect to the distribution of S and Cl, as revealed by energy-dispersive X-ray microanalysis. High levels of S were restricted to the conceptacle’s ECM, whereas the ECM in the medulla was always S poor and Cl rich. Receptacles frozen naturally at low tide during the winter of 1998 showed extensive damage in the medulla, and this likely accounts for the cessation of reproduction during the winter on the Maine shore. The damaged receptacles recovered and resumed growth during the spring, and they released gametes by May. Abscission of the overwintered receptacles was observed in June to July, coincident with the formation of new receptacles at the tips of newly grown portions of the fronds.

The two CorallinalesPhymatolithon calcareum and Lithothamnion corallioides are the main components of European maerl communities. A large majority of the thalli are free-living branches borne on juvenile crusts that are rarely found. A detailed investigation of these juvenile stages has allowed the discovery of their reproductive features. Sexual reproduction of P. calcareum, the type-species of the genus, is described here for the first time and thus gives fundamental data for the generic definition. On the floor of the female conceptacle, a set of carpogonial branches is formed. Each fertilized carpogonium then fuses with the supporting cell of the carpogonial branch, which is also its auxiliary cell. A small fusion cell is thus formed, which produces upwards a small gonimoblast reduced to a short chain of carposporangia. In a mature conceptacle, the surface of the fertile floor thus appears entirely covered with small gonimoblasts. In the male conceptacle, mature spermatangia produced on the floor are typically dendroid; those produced on the walls are of a more simple type. The organization of the asexual conceptacle is briefly reviewed. The reproduction of L. corallioides is also newly described and compared with that previously reported for L. muelleri, the type-species of the genus.Key words: Corallinales, Phymatolithon, Lithothamnion, sexual reproduction, generic definition.

Specimens of a mixed population of Sargassum spp. were collected from Reunion Rocks, KwaZulu-Natal, South Africa over a period of one year. Three general shapes of receptacle were recorded for Sargassum elegans, S. incisifolium and an undescribed species of Sargassum: i) terete, ii) three-cornered and iii) twisted receptacles respectively. The number of conceptacles on the receptacles was enumerated and related to the dry weight of the receptacles. It was found that conceptacle number per receptacle correlated well to the weight of the receptacle and that, each receptacle type had a different number of conceptacles per unit weight Relationships were found to vary from one season to the next, however, it was found that the three-cornered receptacle type developed a greater number of conceptacles per unit weight than the terete receptacle type. Reproductive:somatic biomass ratios indicated that the three-cornered receptacle type had a lower reproductive expenditure than the terete receptacle type in terms of biomass. Ecological and possible taxonomic implications are discussed.

Synarthrophyton robbenense sp. nov. and S. munimentum sp. nov., the fourth and fifth species in this apparently southern hemisphere genus, are described from southern Africa. Synarthrophyton robbenense occurs on rock and shells in the subtidal zone. Its thalli are minutely warty, with the surface covered by short, narrow protuberances that are fused into elongate, scrolled structures. The surface [scanning electron microscopy (SEM)] is of the Leptophytum type. Mature tetra/bisporangial conceptacles have raised rims and sunken pore plates. The pore plates are composed of filaments made up of two or three cells plus an enlarged epithallial cell. The pore canal is lined by filaments with cells that do not differ in size or shape from those of the other filaments making up the pore plate. Cells of filaments within the tetrasporangial and bisporangial conceptacle rim are narrower and more elongate than cells of the pore plate and surrounding vegetative filaments. Tetra/bisporangial pores are surrounde...

Two unbranched species of Lithophyllum are characterized from Fiji, South Pacific, where both are common in the shallow reef environment. Lithophyllum insipidum Adey, Townsend et Boykins is characterized by a mainly lavender-colored thallus that is tessellate, with chalky white to brownish patches. Basal filaments are composed of nonpalisade cells that are rectangular prisms shaped like a book. The thallus surface, viewed by scanning electron microscopy, is of the Leptophytum type. Tetrasporangial pores are not blocked by occluding cells, and the tetrasporangial pore canal is lined by papillae that project into the pore canal. The floor of the tetrasporangial conceptacle chamber is six to nine cells deep, and the tetrasporangial conceptacle roof is formed from filaments that originate both peripheral to and central to a ring-shaped fertile area. A columella is present, and tetrasporangia are located at the conceptacle periphery. Tetrasporangial conceptacles are buried in the thallus after their s...

Mesophyllum incisum is reported and studied for the first time in South Africa. It has a thallus surface (SEM) with Leptophytum-type epithallial cells. Tetra/bisparangial conceptacles are mound-like and lack a peripheral rim but have a flattened pore plate. The rosette cells surrounding the tetrasporangial pores are distinct from surrounding roof cells (SEM, surface view) in being narrower, and sunken below the level of the surrounding pore plate. The cells of filaments bordering the tetrasporangial conceptacle pore canal differ from the other roof cells within the pore plate in being more elongate, narrower, and often more densely staining. Pore canal filaments also generally contain fewer cells than the surrounding filaments of the pore plate and the pore canal is more-or-less parallel sided. Our material agrees closely with the species as reported in Australia.

Studies of the genus Amphiroa (Corallinales, Rhodophyta) along the southern Baja California Peninsula, Mexico, were undertaken to determine how many species were present and to assess the characters that have been or could be used in species delimitation. After analysis of 800 specimens from 60 localities, we conclude that five species are present: A. valonioides Yendo, A. misakiensis Yendo, A. vanbosseae Lemoine, A. rigida Lamouroux and A. beauvoisii Lamouroux. Amphiroa brevianceps Dawson and A. magdalensis Dawson are considered heterotypic synonyms of A. misakiensis. Characters used here for the first time to delimit species of Amphiroa include shape of gametangial conceptacle chambers, ontogeny of the pore of the gametangial conceptacle, the type of spermatangia present, the position of gonimoblast filaments and the form of the cortical cells. Characters used in species delimitation in Amphiroa are discussed in detail and a key to the species found in southern Baja California is provided.

SUMMARY A new species of semi-endophytic coralline alga, Lithophyllum cuneatum (Corallinaceae: Lithophylloideae), is described from Fiji. The species is characterized by a wedge-like thallus that is partially buried in the thallus of the host coralline, Hydrolithon onkodes (Heydrich) Penrose et Woelkerling or occasionally Neogoniolithon sp., and that appears at the surface of the host as a small pustule that is usually paler in color than the host. The thallus consists of erect filaments that are derived from a single cell. The basal cell, when visible, is non-palisade, and areas of bistratose margin are absent. Cells of contiguous erect filaments are joined by secondary pit connections. Epithallial cells are present in 2–3 layers, and individual trichocytes are common. Gametangial plants are dioecious. Male conceptacles have simple spermatangial systems that are confined to the floors of their elliptical chambers. Carposporangial conceptacles contain 5–8 celled gonimoblast filaments that are borne at the margin of a more-or-less discoid fusion cell, and so occupy the periphery of the elliptical conceptacle chambers. Tetrasporangial conceptacles are uniporate, with roofs formed from peripheral filaments, and chambers lack a central columella of sterile filaments. Despite its semi-endophytic nature, haustorial cells are absent, and plastids and pigmentation are present.

SUMMARY The mature female conceptacle of Sargassum horneri (Turner) C. Agardh has an ostiole filled with a gelatinous plug. The oogonium in the conceptacle has cell walls that can be differentiated into a dense outer and a less dense inner microfibrillar layer. Just prior to egg release, stalk material is produced inside the outer layer and the inner layer disappears. At this stage the gelatinous plug is extruded and mucilage is released through the ostiole. The released eggs are retained on the receptacle by the stalk and are surrounded by a large amount of the mucilage. Three-celled germlings form a primary wall with a polylamellated structure of microfibril layers. In multicellular germlings that have differentiated into thallus and rhizoids, the peripheral thallus cells have an outer cell wall consisting of a microfibril layer under the primary wall, while the cell wall of the rhizoid tip has an amorphous structure. The germlings are released from the stalk and become attached to the substratum by an adhesive substance secreted from rhizoidal cells.

The genus Synarthrophyton (Corallinaceae, Rhodophyta) is represented in southern Australia by one species, S. patena (Hooker et Harvey in Harvey) Townsend. New data have shown that cell fusions vary in size and occur in both anticlinal and periclinal cell walls, and as a result can no longer be used to delimit Synarthrophyton from other genera of Melobesioideae. Male conceptacle development is described for the first time. Spermatangia are overlain by protective cells during early stages of development. Mature spermatangial branches may be either dendroid or both dendroid and simple. Growth-form is more varied than hitherto thought and includes specimens previously identified as Lithothamnion muelleri Lenormand ex Rosanoff. An updated description of Synarthrophyton is presented and the relationships of Synarthrophyton to other genera of the subfamily Melobesioideae are considered. New information is provided on host range, seasonal and geographic distribution in southern Australia.

Hydrolithon pellire sp. nov. (Rhodophyta, Corallinaceae) is a thin, crustose epiphyte that grows mainly on intertidal plants of Gelidium pteridifolium R.E. Norris, Hommersand et Fredericq in Natal and eastern Cape Province, South Africa. It has cell fusions and uniporate tetrasporangial conceptacles characteristic of the subfamily Mastophoroideae. The conceptacle pore is surrounded by enlarged, vertically oriented cells characteristic of the genus Hydrolithon. Hydrolithon pellire appears to have a germination disc of c. 48, small, squarish cells; this type of disc is normally associated with the multiporate genus Melobesia.

Pneophyllum amplexifrons (Harvey) comb. nov. is an epiphytic crustose coralline alga (Rhodophyta, Corallinaceae) of the subfamily Mastophoroideae. It occurs commonly in northern Natal, South Africa and is particularly abundant on intertidal populations of the seagrass Thalassodendron ciliatum (Forsskaring;l) den Hartog. It agrees well with the type specimen of Melobesia amplexifrons Harvey. A germination disc with 8 central cells is present, as usually seen in Pneophyllum. The roof of the tetrasporangial conceptacle forms from filaments surrounding and filaments interspersed among sporangial initials. A pore canal lined with numerous small cells confirms that the species pertains to the mastophoroid genus Pneophyllum. Two diagnostic features of P. amplexifrons are humps of uncalcified filaments at the thallus surface and tapered pore canals in the tetrasporangial conceptacles, lined with small, upward-pointing, non-protruding filaments. Comparison with syntypes of Lithophyllum pseudolichenoides H...