25 research outputs found

    Development of the red algal parasite Vertebrata aterrimophila sp. nov. (Rhodomelaceae, Ceramiales) from New Zealand

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    © 2019, © 2019 British Phycological Society. Parasitic red algae grow only on other red algae and have over 120 described species. Developmental studies in red algal parasites are few, although they have shown that secondary pit connections formed between parasite and host and proposed that this was an important process in successful parasitism. Furthermore, it was recorded that the transfer of parasite nuclei by these secondary pit connections led to different host cell effects. We used developmental studies to reconstruct early stages and any host cell effects of a parasite on Vertebrata aterrima. A mitochondrial marker (cox1) and morphological observations (light and fluorescence microscopy) were used to describe this new red algal parasite as Vertebrata aterrimophila sp. nov. Early developmental stages show that a parasite spore connects via secondary pit connections with a pericentral host cell after cuticle penetration. Developmental observations revealed a unique connection cell that grows into a ‘trunk-like’ structure. Host cell transformation after infection by the parasite included apparent increases in both carbohydrate concentrations and nuclear size, as well as structural changes. Analyses of molecular phylogenies and reproductive structures indicated that the closest relative of V. aterrimophila is its host, V. aterrima. Our study shows a novel developmental parasite stage (‘trunk-like’ cell) and highlights the need for further developmental studies to investigate the range of developmental patterns and host effects in parasitic red algae

    Genetic diversity of sympatric Schizymenia dubyi and S. apoda (Schizymeniaceae, Rhodophyta) in Wellington Harbour, New Zealand

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    Schizymenia dubyi is reported as a new introduction in Wellington, which already has introduced S. apoda. These species coexist in tidepools and the crustose sporophyte is for the first time reported from this population. The diversity and species status of these two species was explored using mitochondrial, plastid and nuclear markers. Haplotypes of rbcL in New Zealand samples of S. dubyi match a haplotype found in Australia that was considered as ‘introgressed’ into S. apoda. COI haplotypes of S. dubyi from New Zealand are also similar to specimens from Australia and Europe, although New Zealand S. apoda samples have a unique haplotype. ITS ribotypes of S. dubyi from New Zealand also are shared with Australia and Europe, while again S. apoda ribotypes are unique. Phylogenetic and network analyses show that these two species are very closely related, and the hypothetical ‘introgressed’ nature of specimens is not supported by phylogenetic analyses. In addition, species delimitation methods are not congruent and do not clarify the species status of these two entities. Morphologically, these species are not distinct, except that in S. dubyi the cystocarp ostiole may be in a depression. The apparent incongruence between markers, leading to the hypothesis of introgression, is probably due to the early stages of the speciation process during which species have a ‘paraphyletic’ phase, in which stochastic incomplete lineage sorting leads to ancestral haplotypes being retained differentially, versus hybridization, introgression and non-maternal inheritance of organelles. Whether these two entities are distinct species needs to be reconsidered, as many species criteria are not met (e.g. monophyly) or need to be tested (e.g. reproductive barriers)

    Utility of molecular-assisted alpha taxonomy of the genus Cystophora (Fucales, Phaeophyceae) from New Zealand and Australia

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    © 2018 International Phycological Society. Many brown macroalgal species are difficult to identify because of limited morphological differentiation and/ or high levels of plasticity. Molecular methods for distinguishing species coupled with morphological examination have been useful in clarifying species status in many groups. Cystophora is a species-rich, morphologically complex brown algal genus that has been carefully monographed, and it is ideal for testing the utility of molecular markers for genetic species delimitation. We evaluated the utility of the cytochrome oxidase subunit 1 (COI) DNA-barcode marker, alone and in combination with nuclear-encoded internal transcribed spacer (ITS) rDNA, in delimiting species. We also used several methods to delimit putative genetic species. Our results showed that for consistent species delimitation and species delimitation that approximates morphological species, both markers in combination are necessary. Most species in the genus are morphologically recognizable and genetically distinct but neither COI nor combined COI-ITS data separate Cystophora congesta from Cystophora retroflexa or Cystophora distenta from Cystophora scalaris. We showed that morphological characters used to separate these two species pairs are highly variable among samples, with many intermediates. Thus, we concluded that these are not independent species and synonymize these species. Our data showed that this genus, while widespread, mostly conforms to a morphospecies concept

    Three new red algal parasites from New Zealand: Cladhymenia oblongifoliaphila sp. nov. (Rhodomelaceae), Phycodrys novae-zelandiaephila sp. nov. (Delesseriaceae) and Judithia parasitica sp. nov. (Kallymeniaceae)

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    2018 International Phycological Society There are over 120 species of red algal parasites (Florideophyceae) but they are often overlooked due to their small size and patchy distribution. Red algal parasites have mostly been described as independent genera but recent phylogenetic studies have shown that parasites are related to free-living relatives, often their hosts, and have been named in these genera to maintain monophyly. We investigated the morphology, distribution and phylogeny, using diverse molecular markers (mitochondrial, nuclear, plastid), of three new red algal parasites in New Zealand. We describe the parasites using morphological and anatomical observations and estimate their distribution by surveying herbarium vouchers. Analyses of reproductive structures and molecular phylogenies indicate that the closest relative of the parasite Phycodrys novae-zelandiaephila sp. nov. is its host, Phycodrys novae-zelandiae. Based on nuclear and mitochondrial markers, the closest relative of the parasite Cladhymenia oblongifoliaphila sp. nov. is its host Cladhymenia oblongifolia but plastid markers group it with Cladhymenia lyallii, suggesting that this species was a past host and the source of parasite plastids. The parasite Judithia parasitica sp. nov. groups with Judithia delicatissima but infects Blastophyllis spp., suggesting that this parasite evolved as a free-living or parasitic Judithia species, and host switching may have occurred. This study adds to our knowledge of New Zealand red algal parasites and highlights contrasting patterns of host–parasite relationships

    Non-monophyly of Bostrychia simpliciuscula (Ceramiales, Rhodophyta): Multiple species with very similar morphologies, a revised taxonomy of cryptic species

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    © 2017 Japanese Society of Phycology The discovery of a plethora of cryptic species in many algal groups has led to speculation as to the causes of this observation and has affected taxonomy, with reluctance to give names to species that look identical. While this is defensible for monophyletic cryptic species complexes, both our understanding of similar morphologies (crypsis) and nomenclature is challenged when we encounter non-monophyletic ‘cryptic’ species. Bostrychia simpliciuscula is a wide-ranging species in which multiple cryptic species are known. Our increased sampling shows that this species consists of four lineages that do not form a clade, but lineages are sister to species with different morphologies. Careful morphological examination shows that characters, especially branched monosiphonous laterals and rhizoid morphology in haptera, are able to distinguish these four lineages into two groups, that are still not monophyletic. The similar morphologies in these lineages could be due to convergence, but not developmental constraints or lack of time to diverge morphologically; or possibly maintenance of a generalized body plan. These lineages appear to have specific biogeographic patterns and these will be used to propose a new taxonomy. B. simpliciuscula is now confined to the tropics. Another of these lineages matches a previously described species, B. tenuissima, that was synonymized with B. simpliciuscula and is from cold temperate Australasia, and is resurrected. Another lineage is found in Japan in which a previous name is also available, B. hamana-tokidae; the last lineage is found in central New South Wales, morphologically it resembles B. tenuissima, with which it overlaps in distribution around Sydney, and is named as a new species, B. kingii sp. nov

    Contrasting patterns of population structure and demographic history in cryptic species of Bostrychia intricata (Rhodomelaceae, Rhodophyta) from New Zealand

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    This is the peer reviewed version of the following article: [Muangmai, N., Fraser, C.I., and Zuccarello, G.C. (2015). Contrasting patterns of population structure and demographic history in cryptic species of Bostrychia intricata (Rhodomelaceae, Rhodophyta) from New Zealand. Journal of Phycology 51, 574–585.], which has been published in final form at https://doi.org/10.1111/jpy.12305. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions: https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html#3

    Hidden diversity in high-latitude Southern Hemisphere environments: Reinstatement of the genus Rama and description of Vandenhoekia gen. nov. (Cladophoraceae, Ulvophyceae, Chlorophyta), two highly variable genera

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    The continental coasts and remote islands in the high-latitude Southern Hemisphere, including the subantarctic region, are characterized by many endemic species, high abundance of taxa, and intermediate levels of biodiversity. The macroalgal flora of these locations has received relatively little attention. Filamentous green algae are prolific in the intertidal of southern islands, but the taxonomy, distribution, and evolutionary history of these taxa are yet to be fully explored, mostly due to the difficulty of access to some of these locations. In this study, we examined specimens of the order Cladophorales from various locations in the high-latitude Southern Hemisphere including the subantarctic (the Auckland Islands, Bounty Islands, Campbell Island, Macquarie Island, and Kerguelen Islands), as well as mainland New Zealand, the Chatham Islands, Chile, and Tasmania. The analyses of the rDNA sequences of the samples revealed the existence of two new clades in a phylogeny of the Cladophoraceae. One of these clades is described as the novel genus Vandenhoekia gen. nov., which contains three species that are branched or unbranched. The amended genus Rama is reinstated to accommodate the other clade, and contains four species, including the Northern Hemisphere “Cladophora rupestris.” In Rama both branched and unbranched morphologies are found. It is remarkable that gross morphology is not a predictor for generic affiliations in these algae. This study illustrates that much can still be learned about diversity in the Cladophorales and highlights the importance of new collections, especially in novel locations

    Red algal parasites: A synopsis of described species, their hosts, distinguishing characters and areas for continued research

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    © 2017 Walter de Gruyter GmbH, Berlin/Boston. Red algal parasites are diverse organisms that are unusual due to the fact that many are closely related to their hosts. Parasitism has developed many times within different red algal groups, but the full extent of parasite biodiversity is unknown, as parasites are easily overlooked due to their small size and often low abundance. Additionally, the literature on red algal parasites is dispersed and has not been compiled in over 30 years. Although criteria have been proposed to define what constitutes a red algal parasite, many parasites are poorly described, and the cellular interactions with their host are poorly known. A few studies have demonstrated that parasites transfer organelles to host cells, which can alter the physiology of the host to the benefit of the parasite. Here, we apply a set of defining criteria for parasites to a compiled list of all described red algal parasites. Our results highlight the lack of knowledge of many key parasitic processes including early parasite development, host cell "control", and parasite origin. Until the biology of more parasites is studied, generalisations on the processes of parasitism in red algae may be premature. We hope this synopsis will stimulate research into this fascinating group
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