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

© 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.

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

© 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.

The genus Phyllophorella (Phyllophoraceae, Rhodophyta) on the central coast of Peru, range extensions and anatomical description of the female gametophyte and carposporophyte

Phyllophorella was recently described from two localities on the central coast of Peru (12°S), based on the endemic species Phyllophora (Ph.) peruviana. The genus currently accommodates three species, Phyllophorella (P.) peruviana, P. humboldtiana and P. limaensis. Recent field surveys for Phyllophorella on the central coast of Peru led to the discovery of collections outside the originally reported ranges. Morphological, anatomical, and genetic characterization of the specimens confirms range extensions for P. peruviana to 9° S and 15° S, and P. humboldtiana to 12° S and 15° S. A combined phylogenetic analysis of rbcL and COI-5P gene sequences supports the taxonomic status of these two species and reasserts the genus as monophyletic. Anatomically, the two species differ in nemathecial structure. Phyllophorella peruviana displays dome-shaped and well-defined circular nemathecia, whereas in P. humboldtiana they are irregular and diffuse in form. Mature cystocarps were observed for the first time in Phyllophorella, in P. humboldtiana from Lima and Ica, Peru. Phyllophorella, as well as the other genera classified to the family Phyllophoraceae, have a procarpic sexual system, with a carpogonial branch of three cells; the cystocarp develops a thickened cortex, is immersed in the medulla, and lacks a pericarp and an ostiole. This study demonstrates that field work, together with morphological, developmental, and genetic analyses, are useful methods for improving our understanding of seaweed distributions and systematics.

Batrachospermum (Batrachospermales, Rhodophyta) in Australia and New Zealand: New taxa and records in sections Contorta and Hybrida

Six species of Batrachospermum from Australia and New Zealand have a twisted to coiled carpogonial branch and determinate gonimoblast filaments, and are therefore referable to section Contorta or Hybrida. Batrachospermum australicum KÜtz. ex sp. nov. from large rivers in tropical Northern Territory has a tightly 3-coiled carpogonial branch; B. vittatum sp. nov. from tropical Northern Territory has a characteristic longitudinal mid-whorl band of spermatangia; and B. deminutum sp. nov. from a single locality in eastern-central New South Wales has reduced whorls and long carpogonial branches. The other three species are cosmopolitan in distribution: B. virgatodecaisneanum Sirodot is widespread but uncommon in temperate regions of both countries; B. ambiguum Montagne is widespread and common in tropical Australia; and B. globosporum Israelson is restricted in Australia to near Brisbane in subtropical southern Queensland.

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

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.

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

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.

The Red Algae Genus Callophyllis Kützing (Kallymeniaceae, Gigartinales) from Eastern Mainland Australia, with Notes on the Genus Ectophora J. Agardh

Two species attributable to Callophyllis, a genus only recently recorded from eastern mainland Australia, are described from subtidal habitats in New South Wales. One of the species closely conforms to the New Zealand endemic Callophyllis ilepressa (J. Agardh) Laing, formerly the type species of the genus Ectophora J. Agardh. Although full reproductive details of this species are lacking, evidence in this survey strongly suggests that the genus was and is correctly placed in synonymy with Callophyllis. Thalli of C. depressa consist of prostrale, spreading, imbricate blades firmly anchored to rocky substrata by numerous haptera arising from the under surfaces. Upper frond surfaces are iridescent in localised patches corresponding to nests of refractive subcortical cells. The outer cortex in cross section comprises three to six layers and is composed of anticlinal filaments lacking secondary pit connections. The medulla consists of large, subisodiametric cells interspersed with narrow filaments. Plants appear to be procarpic, the supporting cells bearing a single three-celled carpogonial branch and several elaborately lobed, elongated, sterile cells. The second species is named Callophyllis nana sp. nov. for its diminutive (1.5 to 3 cm in length) fronds. Blades overlap, anastornose, and attach to rocky or bryozoan substrata by a single basal holdfast. The cortex is single-layered, the medulla being one to several layers of large subisodiametric cells interspersed with narrow filaments. Plants appear to be procarpic, the supporting cells bearing a single three-celled carpogonial branch and several relatively unlobed, short, bulbous sterile cells. Because of the inclusion of Ectophora into Callophyllis, the new name Callophyllis laingiaiia is proposed to replace Callophyllis dichotoma (J. Agardh) Laing [non C. dichotoma (Hooker et Harvey in Hooker) Kützing].

The life history of Palmaria palmata in culture. A new type for the Rhodophyta

The life history of Palmaria palmata has been completed in culture. Tetraspores from diploid plants gave rise to male and female haploid plants which differed morphologically. Female plants were extremely small and became sexually mature only days after tetraspore release. Trichogynes were observed on plants only 4 days old, and remained conspicuous for several weeks. As the females aged, trichogynes declined in number and they could not be detected on plants 5 months old. In contrast, male plants required several (9–12) months of vegetative growth before they formed spermatia. As a consequence, females had to be fertilized by older males from preceding gametangial generations.The diploid tetrasporangial plants developed directly on fertilized females. As they enlarged, they completely overgrew the small females and formed their own holdfast attachments to the substrate. A recessive mutation resulting in green frond colour was used in crosses designed to yield red diploid tissue on green females after fertilization, thereby greatly facilitating observations on the development of the tetrasporangial phase.Preliminary observations indicate that the carpogonium is a single cell. There appears to be no carpogonial branch or auxilliary cell. The tetrasporangial phase develops from the zygote by simple mitotic divisions, suggesting that the life history is best interpreted as lacking a carposporophyte.

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

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.