Alan J. K. Millar

ABSENCE OF A LARGE BROWN MACROALGA ON URBANIZED ROCKY REEFS AROUND SYDNEY, AUSTRALIA, AND EVIDENCE FOR HISTORICAL DECLINE1

Loss of habitat‐forming algae is increasingly prevalent in temperate marine ecosystems. Here, we document absence of an important habitat‐forming macroalga, Phyllospora comosa (Labill.) C. Agardh, along an urbanized coast in New South Wales (NSW), Australia. Dense Phyllospora canopies were common on shallow sublittoral reefs north and south of Sydney. In contrast, we did not find a single individual along ∼70 km of rocky coastline in the Sydney metropolitan region, despite historical evidence to suggest that it was very common half a century ago. Recolonization of this important habitat‐forming alga has not occurred on Sydney reefs despite improved water quality, protection of its habitat, and frequent long‐distance dispersal of Phyllospora wrack. While there are obvious limitations, historical information can be useful for identifying potential shifts in community structure to increase our understanding of contemporary ecological patterns.

Endangered algal species and how to protect them

Brodie J., Andersen R.A., Kawachi M. and Millar A.J.K. 2009. Endangered algal species and how to protect them. Phycologia 48: 423–438. DOI: 10.2216/09-21.1. In August 2005 at the Eighth International Phycological Congress in Durban, South Africa, a workshop brought together expertise in an attempt to answer some major questions regarding the conservation of algae. The outcome, presented here, considers whether microalgal and macroalgal species are endangered and what possible methods and tactics are necessary to achieve realistic protection, including the potential use of culture collections in the conservation of algae and application of legislation that exists to protect species and habitats. There is evidence that there are endangered algae and that some have become extinct in recent years. The concept for the microalgae that ‘everything is everywhere’ is challenged. Evidence that some species have restricted ranges means that their biogeography has to be taken into account in their conservation. For the marine macroalgae, evidence of the impact of climate change, ocean acidification and introduced species on native floras is often anecdotal and points to the need for long-term monitoring and scientific study to determine changes in abundance and distribution. The use of species and site designations, including biodiversity action plans, important plant areas and key biodiversity areas are explored as ways forward for algal conservation and the raising of public awareness. Ex situ conservation in the form of actively growing culture collections or in suspended animation cryogenically is a means of conserving algae at least for a restricted number of species and as a last resort; although, the success of reintroductions is unknown. Legislation is considered as the best method in which algae can be given protection. It is concluded that taxonomic knowledge and a global approach are vital to the conservation of the algae.

Morphology and molecular phylogeny of the marine algal order Gelidiales (Rhodophyta) from New South Wales, including Lord Howe and Norfolk Islands

Fifteen species in seven genera of the marine benthic red algal order Gelidiales are reported from the New South Wales coast including Lord Howe Island and Norfolk Island. Critical sampling, a re-examination of herbarium specimens filed in the Royal Botanic Gardens Sydney and the University of Melbourne, and molecular sequencing of most of the species has determined that many of the previous identifications from this region of the Pacific were incorrect. Gelidium pusillum (Stackhouse) Le Jolis, once widely reported from this coast, is shown not to occur here and the specimens on which these misidentifications were made have proved to represent either new species or previously described species. Similarly, records of Gelidium australe J. Agardh have been found to represent misidentification of the formerly New Zealand endemic Gelidium allanii V.J.Chapman, and specimens identified as Gelidium caulacantheum J. Agardh actually represent the new species Gelidium hommersandii sp. nov. Previously recorded species verified in this study are Capreolia implexa Guiry & Womersley, Gelidiella acerosa (Forsskal) Feldmann & G.Hamel, Gelidium maidenii Lucas, Pterocladia lucida (Turner) J. Agardh, Pterocladiella caerulescens (Kutzing) Santelices & Hommersand [as Pterocladia caerulescens (Kutzing) Santelices], Pterocladiella capillacea (Gmelin) Santelices & Hommersand [as Pterocladia capillacea (Gmelin) Bornet], and Ptilophora pectinata (A. & E.S. Gepp) R.E.Norris. These species are described and illustrated in detail along with previously unreported reproductive structures. Three species are newly recorded for the New South Wales mainland [Parviphycus antipae Celan, Gelidium crinale (Turner) Gaillon, and Pterocladiella caloglossoides (Howe) Santelices], and two species (Gelidium isabelae W.R.Taylor and Gelidium allanii V.J.Chapman) represent new records for the Australian continent. In addition, three new species are described: Gelidium bernabei sp. nov., Gelidium declerckii sp. nov., and Gelidium hommersandii sp. nov.

An account of the Hapalidiaceae (Corallinales, Rhodophyta) in south-eastern Australia

This paper provides the first monographic account of south-eastern Australian representatives of the Hapalidiaceae (Corallinales, Rhodophyta). The Hapalidiaceae includes those Corallinales whose tetrasporangia produce zonately arranged spores, and whose tetrasporangia/bisporangia are borne in conceptacles, produce apical plugs, develop beneath multiporate plates or roofs, and are not enclosed individually within calcified sporangial compartments. The Hapalidiaceae contains the subfamilies Choreonematoideae, Melobesioideae and Austrolithoideae, all formerly placed in the Corallinaceae sensu lato. The Choreonematoideae is represented in south-eastern Australia by a single species, Choreonema thuretii. The Melobesioideae is represented by five genera (Melobesia, Lithothamnion, Phymatolithon, Mesophyllum, Synarthrophyton) and eight species. Synarthrophyton pseudosorus sp. nov. is newly described. The presence of tetrasporangial conceptacles occurring in irregularly shaped dense clusters that contain both discrete conceptacles and fused groups of conceptacles delimits this species from all other species of Synarthrophyton. Morphological and anatomical accounts are provided, including keys, information on distribution, habitat and nomenclature. Brief biogeographic comparisons between south-eastern Australia and neighbouring regions are also made.

The Sporolithaceae (Corallinales, Rhodophyta) in south-eastern Australia: taxonomy and 18S rRNA phylogeny

Abstract The family Sporolithaceae (Corallinales, Rhodophyta) is represented in south-eastern Australia by two species: Heydrichia homalopasta and Sporolithon durum. Morphological and anatomical accounts are provided, including a key to species, and information on distribution, seasonality, habitat and nomenclature. Analyses of characters previously proposed for the delimitation of genera within the Sporolithaceae show similarities, overlaps or uncertainties for most character states. The presence of an involucre surrounding the tetrasporangial compartments in Heydrichia (and the absence of an involucre in Sporolithon) has proven a useful and stable character in delimiting these genera. Data from south-eastern Australian collections of H. homalopasta have also shown that features relating to tetrasporangial compartments are useful in delimiting H. homalopasta from other species of Heydrichia. These include the presence of solitary tetrasporangial compartments and the absence of successive tetrasporangia. New 18S rRNA sequence data from S. durum and H. homalopasta were combined with selected published sequences of coralline red algae. All phylogenetic reconstruction methods resolved H. homalopasta and H. woelkerlingii as sibling taxa in a strongly supported clade. Molecular data are consistent with the known morphological data and with recognition of H. homalopasta as a distinct species. Phylogenetic reconstructions consistently placed Sporolithon and species of Heydrichia in a strongly supported clade with Rhodogorgon carriebowensis, a species generally regarded as belonging to a separate order (Rhodogorgonales). This result is inconsistent with known morphological and reproductive features.

The Corallinaceae, subfamily Mastophoroideae (Corallinales, Rhodophyta) in south-eastern Australia

The first monographic account of the south-eastern Australian representatives of the Corallinaceae, subfamily Mastophoroideae (Corallinales, Rhodophyta) is presented. The Mastophoroideae contains eight extant genera, four of which [Hydrolithon, Mastophora, Neogoniolithon, Pneophyllum] were confirmed to occur in south-eastern Australia. Hydrolithon is represented by six species (H. farinosum, H. improcerum, H. munitum, H. onkodes, H. rupestre and H. samoense). Pneophyllum is represented by three species (P. coronatum, P. fragile and P. submersiporum) while Mastophora and Neogoniolithon are represented by a single species each (Mastophora pacifica and Neogoniolithon brassica-florida). Morphological and anatomical accounts are provided, including keys to genera and species, comparisons with related south-eastern Australian mastophoroid species, information on distribution, seasonality, habitat and nomenclature. Brief biogeographical comparisons between south-eastern Australia and other Australasian regions are also made.

ASTEROMENIA (RHODYMENIACEAE, RHODYMENIALES), A NEW RED ALGAL GENUS BASED ON FAUCHEA PELTATA

Asteromenia gen. nov. (Rhodymeniales, Rhodophyta) is proposed with a single species, Asteromenia peltata (W. R. Taylor) comb. nov. (basionym: Fauchea peltata W. R. Taylor). Thalli of the proposed new genus are stipitate with dorsiventral, peltate blades that are initially circular in shape but with age become stellate with ligulate arms. Internally, the blades have a polystromatic medulla of large, hyaline cells, grading into a cortex of smaller, pigmented cells. Clusters of translucent cells occur on the dorsal surface of the blade. Tetrasporangia are formed by transformations of intercalary midcortical cells. Mature tetrasporangia have cruciately arranged spores and are densely aggregated in the cortex, mostly on the ventral surface, but occasional tetrasporangia also arise on the dorsal surface. Carpogonial branches are four‐celled and arise on inner cortical cells. Auxiliary cells are borne on auxiliary mother cells attached to supporting cells of the carpogonial branches. Cystocarps are protuberant, with well‐developed, ostiolate pericarps that often have extended, proboscis‐like necks. The new genus differs from the previously described peltate or dorsiventral taxa in the Rhodymeniaceae by its polystromatic medulla (Maripelta and Sciadophycus have a monostromatic medulla), intercalary tetrasporangia formed in an unmodified cortex, and four‐celled carpogonial branches (Halichrysis, as typified by H. depressa (J. Agardh) F. Schmitz, has terminal tetrasporangia in nemathecia and three‐celled carpogonial branches).

Redefining the taxonomic status of Laurencia dendroidea (Ceramiales, Rhodophyta) from Brazil and the Canary Islands

Morphological and molecular studies have been performed on Laurencia dendroidea derived from Brazil and the Canary Islands. This species possesses all of the characters that are typical of the genus Laurencia, including the production of the first pericentral cell underneath the basal cell of the trichoblast; the production of tetrasporangia from particular pericentral cells without the formation of additional fertile pericentral cells; spermatangial branches that are produced from one of two laterals on the suprabasal cell of the trichoblasts; and a procarp-bearing segment that possesses five pericentral cells. The phylogenetic position of L. dendroidea was inferred by analysing the chloroplast-encoded rbcL gene sequences of 51 taxa. Phylogenetic analyses revealed that the taxa previously identified and cited in Brazil as Laurencia filiformis, L. majuscula and L. obtusa and in the Canary Islands as L. majuscula all represent the same taxonomic entity and examination of type material allowed us to identify this entity as L. dendroidea, whose type locality is in Brazil. Laurencia obtusa from the Northern Atlantic is confirmed to represent a distinct species, which displays high genetic divergence with respect to western and eastern Atlantic samples. The phylogenetic analyses also supported the nomenclatural transfer of Chondrophycus furcatus (Cordeiro‐Marino & M.T. Fujii) M.T. Fujii & Sentíes to Palisada furcata (Cordeiro‐Marino & M.T. Fujii) Cassano & M.T. Fujii comb. nov.

DASYA ROSLYNIAE SP. NOV. (DASYACEAE, RHODOPHYTA), WITH A DISCUSSION ON GENERIC DISTINCTIONS AMONG DASYA, EUPOGODON, RHODOPTILUM, AND POGONOPHORELLA1

Dasya roslyniae sp. nov. (Dasyaceae, Rhodophyta) is described from subtidal habitats at Split Solitary Island (30°14′S, 153°11′E), New South Wales, Australia. The new species is distinct within the genus due to its strongly compressed and secondarily bilaterally branched axes, differing from the majority of Dasya species that are terete and secondarily radially organized. Pseudolaterals are quickly caducous on ventral and dorsal (transverse) surfaces but are persistent on lateral surfaces for short distances from the apex, leaving the bulk of the plants flattened and denuded. Its gross morphological characters are thus similar to those displayed by the genera Pogonophorella, Eupogodon (formerly known as Dasyopsis), and Rhodoptilum. Characters used for separating these genera and Dasya are, in some cases, overlapping and in need of critical evaluation. To the primarily radially organized taxa, determined by examination of divisions of the apical cell, are placed species of Dasya, six species now included in Eupogodon, and the type and only species of Pogonophorella californica. Examination of the activity of the apical cells of Eupogodon planum and Rhodoptilum plumosum, the type species of their genera, confirms the primary bilaterality of these two genera, and the traditional defining feature of Eupogodon (lack of discernible pericentral cells in cross‐section of indeterminate axes) is shown to be untenable. A secondary character that would separate Eupogodon and Rhodoptilum is the polysiphonous bases of otherwise monosiphonous laterals (pseudolaterals) in Eupogodon and the monosiphonous bases in Rhodoptilum.

Recognition of Pachyarthron and Bossiella as Distinct Genera in the Corallinaceae, Subfamily Corallinoideae (Corallinales, Rhodophyta)

W.J. Woelkerling, A.J.K. Millar, A. Harvey and M. Baba. 2008. Recognition of Pachyarthron and Bossiella as distinct genera in the Corallinaceae, subfamily Corallinoideae (Corallinales, Rhodophyta). Phycologia 47: 265–293. DOI: 10.2216/07-85.1 New evidence supports recognition of both Pachyarthron and Bossiella as distinct genera within the Corallinaceae, subfamily Corallinoideae (Corallinales, Rhodophyta). Pachyarthron cretaceum, the type species of Pachyarthron, is confirmed to occur in Australia, and a new study of the designated lectotype of P. cretacea and of plants from Australia, Japan, Canada (British Columbia) and the United States (Alaska, Washington State) has shown that male conceptacles are produced both axially at branch tips and laterally on intergenicula. By contrast, only lateral conceptacles occur in Bossiella. Differences between Pachyarythron and Serraticardia & Marginisporum, the only genera of Corallinoideae known to produce both axial and lateral conceptacles, are outlined, and a comparison of and key to all genera of Corallinoideae are included. An emended generic description of Pachyarthron and an account of P. cretaceum are provided. Brief accounts of four infraspecific taxa never transferred into Pachyarthron but attributed to the homotypic synonym Amphiroa cretaceum also are included. These are Amphiroa cretacea f. breviarticulata (Areschoug) Yendo from the Caribbean; A. cretacea f. capensis (Areschoug) Yendo from South Africa; A. cretacea f. rosariformis Yendo from Japan; and A cretacea f. tasmanica (Sonder) Yendo from Australia. The biogeographic implications for Pachyarthron and Bossiella are reviewed; Bossiella should be removed from the floras of Japan, Korea and China, whereas Pachyarthron should be added.