Studies of Marine algae in the lesser-known families of the Gigartinales (Rhodophyta). II. The Dicranemaceae

1977 ◽  
Vol 25 (2) ◽  
pp. 219 ◽  
Author(s):  
GT Kraft
Keyword(s):  
Marine Algae ◽  
Supporting Cell ◽  
Branch System ◽  
Auxiliary Cell ◽  
Cell Position ◽  
The Family ◽  
Red Algal ◽  
Carpogonial Branch ◽  
Advanced Stages ◽  
Fusion Cell

The red algal family Dicranemaceae (Gigartinales) has been studied with regard to its vegetative and reproductive morphology, The group is composed of two Dicranema species (D. revolutum (C. Ag.) J. Ag. and D. cincinnalis sp, nov.), Peltasta australis J. Ag., Reptataxis rhizophora (Lucas) gen. et comb. nov., and Tylotus obtusatus (Sond.) J . Ag. All except Reptataxis, from Lord Howe I., are endemic to southern Australia. The last three genera are newly added to the family, which is redefined to embrace their early gonimoblast similarities to Dicranema. The species are all multiaxial, zonately tetrasporangiate and monoecious. Dicranema, Peltasta and Reptataxis have broad, cellular cortexes and filamentous medullas, while Tylotus is pseudoparenchymatous throughout. Tetrasporangia are nemathecial in Dieranem, Reptataxis and Tylotus, but scattered in Peltasta. Spermatangia in Dicranema are formed in deeply buried catenate clusters, and are similarly derived but non-catenate in the other genera. The species are all monocarpogonial, and only Tylotus is procarpic. In none of the genera are sterile cells associated with carpogonial branches. In Tylotus the supporting cell of the carpogonial branch fuses with the presumably fertilized carpogonium and becomes the diploidized auxiliary cell. In Dicranema, Peltasta and Reptataxis, 2- or 3-celled carpogonial branches are directed to the thallus surface and presumably fertilized carpogonia fuse with an auxiliary cell not necessarily on the same cortical branch system as the supporting cell. Diploidized auxiliary cells in all four genera form small, irregular fusion cells and emit multiple, filamentous gonimoblasts. Gonimoblast growth is mostly thallus-inward in Dicranema, initially radial in Peltasta and Reptataxis, and lateral and outward in Tylotus and advanced stages of Peltasta and Reptataxis. In Dicranema, Peltasta and Reptataxis an extensive placenta of mixed and connected gonimoblast and vegetative cells forms between the fusion cell and the peripheral carpospore-producing layers. In Tylotus vegetative/gonimoblast cell connections occur mainly at the floor of the cystocarp. Carposporangia develop singly on elongate penultimate gonimoblasts in Dicranema and Tylotus, but form chains in Peltasta and Reptataxis. Cystocarps in all the genera are surrounded by thick ostiolate pericarps. The genera of the Dicranemaceae are distinct from one another on frond and holdfast habits, vegetative structure, carpogonial branch shape, auxiliary cell position, gonimoblast orientation, carposporangial size, and mature cystocarp location and cross section. None of the four genera seem obviously derived from or particularly closely related to any others outside the family, although both Peltasta and Reptataxis show some features susesting possible links to the Sarcodiaceae.

Étude comparée de la reproduction de Phymatolithon calcareum (Pallas) Adey & McKibbin et Lithothamnion corallioides (P. & H. Crouan) P. & H. Crouan (Corallinales, Rhodophyta), et reconsidérations sur la définition des genres

1998 ◽  
Vol 76 (8) ◽  
pp. 1433-1445 ◽  
Author(s):  
M L Mendoza ◽  
J Cabioch
Keyword(s):  
Sexual Reproduction ◽  
Type Species ◽  
Supporting Cell ◽  
Simple Type ◽  
Auxiliary Cell ◽  
Carpogonial Branch ◽  
Juvenile Stages ◽  
Fusion Cell ◽  
Main Components ◽  
First Time

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.

scholarly journals Why one species in New Zealand, Pugetia delicatissima (Kallymeniaceae, Rhodophyta), should become two new genera, Judithia gen. nov. and Wendya gen. nov.

2020 ◽  
Author(s):  
R D’Archino ◽  
SM Lin ◽  
PW Gabrielson ◽  
Giuseppe Zuccarello
Keyword(s):  
New Zealand ◽  
Dna Sequences ◽  
Phylogenetic Analyses ◽  
Supporting Cell ◽  
Rbcl Gene ◽  
Cortical Cells ◽  
Branch System ◽  
The Family ◽  
Carpogonial Branch ◽  
Subsidiary Cells

© 2015 British Phycological Society. Blade-forming red algae occur worldwide and, prior to DNA sequencing, had been notoriously difficult to identify and classify, especially when lacking critical reproductive features. This, coupled in New Zealand with many longstanding assumptions that taxa were identical to non-New Zealand species or genera, resulted in many misapplied names. Pugetia delicatissima R.E. Norris, an endemic New Zealand blade-forming species of the family Kallymeniaceae, is actually comprised of one existing and one new species belonging to two distinct genera, as established by our phylogenetic analyses of DNA sequences from the rbcL gene. Analyses of combined rbcL and LSU genes showed that neither is closely related to the generitype of Pugetia, the northern-eastern Pacific, P. fragilissima Kylin. We propose the names Judithia and Wendya for these two newly revealed genera. In addition to diagnostic rbcL and LSU sequences, Judithia is morphologically and anatomically characterized by rounded to oblong blades that do not taper basally at the stipe, loosely aggregated surface cortical cells and cystocarps lacking both a pericarp and an ostiole, all features observed in the holotype of P. delicatissima. Wendya, in contrast, is characterized by blades that taper both apically and basally, compactly arranged surface cortical cells and cystocarps that have both a pericarp and a distinct ostiole. The two genera also are distinguished from one other, as well as from Pugetia by features of pre- and post-fertilization development, including the number of subsidiary cells produced on carpogonial and auxiliary branch systems, whether subsidiary cells in the carpogonial branch system fuse with the supporting cell or not, and the site of origin of gonimoblast cells. Although small in area, New Zealand hosts ten of the 27 currently recognized genera in the Kallymeniaceae and is the southern-hemisphere region of greatest generic diversification in this family.

scholarly journals Resurrection of the Family Grateloupiaceae Emend. (Halymeniales, Rhodophyta) Based on a Multigene Phylogeny and Comparative Reproductive Morphology

2021 ◽  
Vol 9 ◽  
Author(s):  
Su Yeon Kim ◽  
Hyung Woo Lee ◽  
Eun Chan Yang ◽  
Sung Min Boo ◽  
Juan Lopez-Bautista ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Complex Iii ◽  
Outer Cortex ◽  
Data Set ◽  
Auxiliary Cell ◽  
The Family ◽  
Red Algal ◽  
Fusion Cell ◽  
The Many ◽  
Combined Data

The marine red algal order Halymeniales currently includes two families, the Halymeniaceae and Tsengiaceae, and consist of 38 genera and about 358 species. Phylogenetic analyses on specific taxa of the order are common, but not comprehensive, leaving the many intra-ordinal relationships within the Halymeniales unresolved. To reassess the phylogeny of the Halymeniales, we conducted extensive phylogenetic analyses based on 207 rbcL sequences and multigene analyses (rbcL, psaA, psbA, cox1, and LSU) using 47 taxa from the order. The combined data set fully supports the monophyly of the Grateloupia sensu lato clade. Phylogenetic assessment of the reproductive structures in the order using the type of auxiliary cell ampullae, pericarp origin, and tetrasporangial development characters, supports a Grateloupia sensu lato clade distinct from the Halymeniaceae exemplified by the generitype Halymenia. As a result, we propose to reinstate the family Grateloupiaceae Schmitz based on the Grateloupia sensu lato clade and including Grateloupia and eight other genera: Dermocorynus, Mariaramirezia, Neorubra, Pachymeniopsis, Kintokiocolax, Phyllymenia, Prionitis, and Yonagunia. The emended Grateloupiaceae is distinguished from the Halymeniaceae by the following three characteristics; (i) simple unbranched and unilateral type of auxiliary cell ampullae, (ii) pericarp formed densely by the fusion of secondary medullary filaments from subcortical cells and lateral ampullary filaments from a fusion cell complex, (iii) tetrasporangia originating laterally from the outer cortex. The Halymeniales comprises the monophyletic Grateloupiaceae, Halymeniaceae sensu lato (which requires further study), and the Tsengiaceae.

scholarly journals Why one species in New Zealand, Pugetia delicatissima (Kallymeniaceae, Rhodophyta), should become two new genera, Judithia gen. nov. and Wendya gen. nov.

2020 ◽  
Author(s):  
R D’Archino ◽  
SM Lin ◽  
PW Gabrielson ◽  
Giuseppe Zuccarello
Keyword(s):  
New Zealand ◽  
Dna Sequences ◽  
Phylogenetic Analyses ◽  
Supporting Cell ◽  
Rbcl Gene ◽  
Cortical Cells ◽  
Branch System ◽  
The Family ◽  
Carpogonial Branch ◽  
Subsidiary Cells

© 2015 British Phycological Society. Blade-forming red algae occur worldwide and, prior to DNA sequencing, had been notoriously difficult to identify and classify, especially when lacking critical reproductive features. This, coupled in New Zealand with many longstanding assumptions that taxa were identical to non-New Zealand species or genera, resulted in many misapplied names. Pugetia delicatissima R.E. Norris, an endemic New Zealand blade-forming species of the family Kallymeniaceae, is actually comprised of one existing and one new species belonging to two distinct genera, as established by our phylogenetic analyses of DNA sequences from the rbcL gene. Analyses of combined rbcL and LSU genes showed that neither is closely related to the generitype of Pugetia, the northern-eastern Pacific, P. fragilissima Kylin. We propose the names Judithia and Wendya for these two newly revealed genera. In addition to diagnostic rbcL and LSU sequences, Judithia is morphologically and anatomically characterized by rounded to oblong blades that do not taper basally at the stipe, loosely aggregated surface cortical cells and cystocarps lacking both a pericarp and an ostiole, all features observed in the holotype of P. delicatissima. Wendya, in contrast, is characterized by blades that taper both apically and basally, compactly arranged surface cortical cells and cystocarps that have both a pericarp and a distinct ostiole. The two genera also are distinguished from one other, as well as from Pugetia by features of pre- and post-fertilization development, including the number of subsidiary cells produced on carpogonial and auxiliary branch systems, whether subsidiary cells in the carpogonial branch system fuse with the supporting cell or not, and the site of origin of gonimoblast cells. Although small in area, New Zealand hosts ten of the 27 currently recognized genera in the Kallymeniaceae and is the southern-hemisphere region of greatest generic diversification in this family.

Studies of marine algae in the lesser-known families of the Gigartinales (Rhodophyta). III. The Mychodeaceae and Mychodeophyllaceae

1978 ◽  
Vol 26 (4) ◽  
pp. 515 ◽  
Author(s):  
GT Kraft
Keyword(s):  
Marine Algae ◽  
Adjacent Cell ◽  
Distinctive Pattern ◽  
Supporting Cells ◽  
New Family ◽  
Red Algal ◽  
Single Genus ◽  
Fusion Cell ◽  
Fertile Region ◽  
Axial Development

The endemic Australian red algal families Mychodeaceae Kylin and Mychodeophyllaceae fam. nov. are described and characterized in vegetative and reproductive detail. The Mychodeaceae is composed of the single genus Mychodea and 11 species which are distinguished on habit features and vegetative differences. Plants are uniaxial with a distinctive pattern of axial development, monoecious, zonately tetrasporangiate, procarpic and polycarpogonial. Supporting cells of carpogonial branches function as auxiliary cells which remain unfused to adjacent cells after diploidization and emit numerous gonimoblast filaments towards the centre of the thallus. The gonimoblasts become secondarily pitconnected to gametophytic cells which they lie next to and eventually appear to break up into isolated groups of cells which both initiate additional carposporangial precursors and enlarge directly into carposporangia themselves. Carposporangial initials can form secondary pit-connections to any type of adjacent cell, which results in irregularly branched carposporangial clusters whose cells are frequently attached to sterile gametophytic cells within and around the periphery of the cystocarp. Mature cystocarps consist of a non-ostiolate pericarp and pockets of carposporangia isolated between persistent sterile cells throughout the fertile region. The genera Neurophyllis Zanardini and Ectoclinium J. Agardh are placed in synonymy with Mychodea, and all extra-Australian records of the group are discounted or questioned. A new family, the Mychodeophyllaceae, is created for Mychodeophyllum papillitectum gen. et sp. nov. from Western Australia. Mychodeophyllum shares spermatangial and tetrasporangial features with Mychodea, as well as sexual elements such as polycarpogonial procarps, lack of a fusion cell, and multiple, inwardly growing gonimoblast initials. Gonimoblast filaments develop quite differently from Mychodea, however, and carposporangia form radiating chains around the periphery of a central placenta composed of mixed and secondarily connected gonimoblast and gametophytic filaments. Plants of the genus are also apparently rnultiaxial. The Mychodeaceae and Mychodeophyllaceae appear to be highly specialized in vegetative and carposporophyte structure, and have given rise to no known higher lines of development. It is speculated that both families may represent offshoots from ancestors at a level of carposporophyte complexit) represented by present-day Rhabdoniaceae, Solieriaceae and Rhodophyllidaceae.

The marine algae of Lord Howe Island (NSW) the family Solieriaceae (Gigartinales, Rhodophyta)

Brunonia ◽  
1984 ◽  
Vol 7 (2) ◽  
pp. 217 ◽  
Author(s):  
PW Gabrielson ◽  
GT Kraft
Keyword(s):  
New Species ◽  
Marine Algae ◽  
The Other ◽  
Lord Howe Island ◽  
The Family ◽  
Red Algal

The red algal family Solieriaceae is represented by the three genera Solieria, Meristotheca and Eucheuma at Lord Howe Island (31�33'S.,159�05'E.). Each genus is represented by two species, one of which is widespread geographically and the other newly described. The new species (Solieria anastomosa, Eucheuma deformans, Meristotheca procumbens) are characterized vegetatively and reproductively, as are the three previously described species [Solieria robusta (Greville) Kylin, Eucheuma serra (J. Agardh) J. Agardh, Meristotheca papulosa (Montagne) J. Agardh]. Mychodea halymenioides Zanardini, which is based on a Lord Howe specimen, is placed in synonymy with Meristotheca papulosa. Partly as a result of the Lord Howe study, the Solieriaceae is recircumscribed using a suite of characters that is taxonomically more useful than that currently delimiting the family.

Haraldiophyllum erosum comb. nov. (Delesseriaceae, Rhodophyta) from Southern and Western Australia

1996 ◽  
Vol 9 (1) ◽  
pp. 61 ◽  
Author(s):  
AJK Millar ◽  
JM Huisman
Keyword(s):  
Western Australia ◽  
Supporting Cell ◽  
Red Alga ◽  
The Other ◽  
Sterile Cell ◽  
Cell Groups ◽  
Carpogonial Branch ◽  
Fusion Cell ◽  
Cover Cell

Nitophyllum erosum Harvey (Delesseriaceae, Rhodophyta) is a branched, monostromatic red alga that is readily recognised by its distinctive fringe of branched, multicellular processes. It has been considered to be a member of the genus Myriograrnrne Kylin, since it was thought to have carposporangia borne in short chains, a feature partially diagnostic for that genus. Recent collections of female and cystocarpic material have allowed us to ascertain the structure of the procarp, a feature important in generic placement. The procarp includes two periaxial cells, of which one acts as a cover cell while the other functions as the supporting cell, ultimately bearing two sterile cell groups and a four-celled carpogonial branch. In addition, the carposporophyte includes a distinctive fusion cell that incorporates gametophytic cells from the floor of the cystocarpic cavity, and the carposporangia are single and terminal on gonimoblast filaments. This combination of characters is diagnostic of the genus Haraldiophyllurn, a genus to which we transfer this species as Haraldiophyllum erosurn (Harvey) Millar & Huisman. comb. nov.

Contribution to the flora of marine algae of the coastal zone of the northeastern part of the Sea of Okhotsk

2018 ◽  
Vol 52 (1) ◽  
pp. 63-73
Author(s):  
N. V. Evseeva
Keyword(s):  
Coastal Zone ◽  
Sea Of Okhotsk ◽  
Marine Algae ◽  
Herbarium Material ◽  
Northeastern Part ◽  
The Sea Of Okhotsk ◽  
The Family ◽  
First Time

The revision of the herbarium material, collected in the northern part of the Sea of Okhotsk in 1965–1966 and stored in VNIRO, allowed to expand the taxonomic list of macrophyte algae of the coastal zone of this area. The locations of discovery of 24 previously unmentioned species are described. Myrionema balticum, Ulvella repens, Syncoryne reinkei, Acrochaetium arcuatum were found in the Sea of Okhotsk for the first time. Most species new for the Sea of Okhotsk is represented by epiphytes of the family Ulvellaceae (Chlorophyta). The final taxonomic list of this region, including literature data, consists of 169 species.

First record of Mikrosyphar zosterae (Chordariaceae, Phaeophyceae) in the southern hemisphere and as an endophyte in the brown algal genera Leathesia and Colpomenia

Phytotaxa ◽  
2021 ◽  
Vol 497 (2) ◽  
pp. 113-126
Author(s):  
NUNO T. MARTINS ◽  
CARLOS FREDERICO D. GURGEL ◽  
TRACEY M. SPOKES ◽  
VALÉRIA CASSANO
Keyword(s):  
Southern Hemisphere ◽  
Growth Rates ◽  
Marine Algae ◽  
First Record ◽  
Filamentous Algae ◽  
Ecological Changes ◽  
The Family ◽  
Host Alga

Several filamentous endophytic genera are assigned to the Phaeophyceae, in particular to the family Chordariaceae (Cormaci et al. 2012). Brown endophytic filamentous algae are known to cause infections in host marine algae (Schoenrock et al. 2013; Ogandaga et al. 2016, 2017; Gao et al. 2019). Acting as pathogens, they may cause morphological, physiological and ecological changes in the host alga such as production of galls and wart-like spots, changes in metabolism and growth rates, and changes in survivorship and reproduction (Schoenrock et al. 2013; Ogandaga et al. 2016, 2017; Gao et al. 2019). Among brown algal filamentous endophytes, the genus Mikrosyphar Kuckuck is relatively understudied. To date, only Mikrosyphar zosterae Kuckuck (1895: 177) was studied thoroughly (Ogandaga et al. 2016, 2017).

Ultrastructure of the fusion cell in Faucheocolax attenuata Setch. (Rhodophyta, Rhodymeniales)

1984 ◽  
Vol 72 (1) ◽  
pp. 307-319
Author(s):  
S.G. Delivopoulos ◽  
P. Kugrens
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Basal Cell ◽  
Red Algae ◽  
Helical Structure ◽  
Cell Types ◽  
Floridean Starch ◽  
Auxiliary Cell ◽  
Shaped Cell ◽  
Fusion Cell

The fusion cell in Faucheocolax attenuata Setch. is a highly lobed, thick-walled, multinucleate and irregularly shaped cell originating from the basal cell of the auxiliary cell branch. The formation of the fusion cell occurs by an incorporation of vegetative cells into the basal cell, after dissolution of septal plugs between these cell types. Thus the fusion cell is a syncytium containing only haploid nuclei, as well as unusual mitochondria and plastids. Mitochondria lack cristae and instead contain a tubular helical structure. Plastids are atypical with regard to thylakoid organization in red algae, because they lack the peripheral thylakoid and their photosynthetic thylakoids are aggregated to one side. In addition, they contain large osmiophilic bodies. Nuclear envelopes appear to produce large quantities of membrane cisternae. Floridean starch is absent and the cytoplasm contains few ribosomes. The plasma membrane is irregular and endoplasmic reticulum cisternae are situated parallel to it. Bundles of putative microfilaments were commonly found in nuclei and the cytoplasm. Structural evidence does not support any meristematic, nutritive or secretory functions previously ascribed to fusion cells in other genera.

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