UNB Scholar Research Repository :: Browsing by Author "Saunders, Gary, W."

Browsing by Author "Saunders, Gary, W."

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A DNA barcode examination of the Laminariaceae (Phaeophyceae) in Canada reveals novel biogeographical and evolutionary insights
(Taylor and Francis, 2010) McDevit, Daniel, C.; Saunders, Gary, W.
DNA barcoding is becoming a widely applied tool for the rapid and accurate identification of eukaryotic species. In this study we used the DNA barcode for large-scale screening of the brown algal family Laminariaceae in Canada. With the examination of 194 COI-5P (5′ end of cytochrome c oxidase 1) sequences (150 newly determined) from representatives of this family, we confirmed the presence of 12 species in Canadian waters (Cymathaere triplicata, Laminaria digitata, L. ephemera, L. setchellii, L. solidungula, L. yezoensis, Macrocystis integrifolia, Nereocystis leutkeana, Postelsia palmaeformis, Saccharina groenlandica, S. latissima and S. sessilis). Saccharina groenlandica, a species with a history of taxonomic confusion, was found in the Pacific, Hudson Bay (subarctic) and Atlantic Canada extending greatly our comprehension of the biogeography of this species. Additionally, COI-5P data from S. latissima, combined with ITS results, provided insights into historical distributional patterns and uncovered a hybridization zone between incipient species in this complex. These discoveries highlight how the growth of a worldwide barcode database for the assignment of individuals to genetic species will uncover new perspectives on biogeography and species diversity on a global scale.
A DNA barcode examination of the red algal family Dumontiaceae in Canadian waters reveals substantial cryptic species diversity. 1. The foliose Dilsea–Neodilsea complex and Weeksia
(Canadian Science Publishing, 2008) Saunders, Gary, W.
The field of DNA barcoding is working towards generating a genetic system for the quick and accurate identification of eukaryotic species. For the more systematic minded, however, DNA barcoding offers a new approach towards screening and uniting large numbers of biological specimens in genetic groups as a first step towards assigning them to species and genera in an approach best termed “molecular-assisted alpha taxonomy”. This approach is particularly amenable in organisms with simple morphologies, a propensity for convergence, extensive phenotypic plasticity, and life histories with an alternation of heteromorphic generations. It is hard to imagine a group of organisms better defined by all of these traits than the marine macroalgae. In an effort to assess the utility of the DNA barcode (COI-5′) for testing the current concepts of biodiversity of marine macroalgae in Canada, a study to assess species diversity in the red algal family, Dumontiaceae, was initiated. Through this work I confirm the presence in Canadian waters of Dilsea californica (J. Agardh) Kuntze, Dilsea integra (Kjellman) Rosenvinge, and Neodilsea borealis (I.A. Abbott) Lindstrom of the Dilsea–Neodilsea complex, and Weeksia coccinea (Harvey) Lindstrom for the genus Weeksia. However, our work has uncovered two additional species of the former complex, Dilsea lindstromiae Saunders sp. nov. and Dilsea pygmaea (Setchell) Setchell, and an additional species of the latter, Weeksia reticulata Setchell, effectively doubling representation of these foliose dumontiacean genera in Canadian waters.
A molecular assessment of species diversity and generic boundaries in the red algal tribes Polysiphonieae and Streblocladieae (Rhodomelaceae, Rhodophyta) in Canada
(Taylor and Francis, 2018) Savoie, Amanda, M.; Saunders, Gary, W.
Sequence data generated during a Canadian barcode survey (COI-5P) of the tribes Polysiphonieae and Streblocladieae, a large and taxonomically challenging group of red algae, revealed significant taxonomic confusion and hidden species diversity. Polysiphonia pacifica Hollenberg, P. paniculata Montagne, P. stricta (Dillwyn) Greville and Vertebrata fucoides (Hudson) Kuntze were all complexes of two or more genetically distinct yet overlooked species. One variety of P. pacifica was elevated to the rank of species as P. determinata (Hollenberg) Savoie & Saunders, stat. nov. Several new additions to the Canadian flora were recorded including P. kapraunii Stuercke & Freshwater and P. morrowii Harvey. Subsequent multi-gene (COI-5P, LSU and rbcL) phylogenetic analyses confirmed that the genus Polysiphonia Greville was polyphyletic, and currently assigned species resolved with many other genera. Polysiphonia sensu stricto was restricted to a group of species that formed a monophyletic lineage with the type, Polysiphonia stricta. Carradoriella P.C.Silva was resurrected based on the South African species Carradoriella virgata (C.Agardh) P.C.Silva. Species previously attributed to Polysiphonia were transferred to Carradoriella, Leptosiphonia and Vertebrata as well as to three new genera described here: Acanthosiphonia gen. nov., based on A. echinata (Harvey) comb. nov.; Eutrichosiphonia gen. nov. for E. confusa (Hollenberg) comb. nov. and E. sabulosia (B.Kim & M.S.Kim) comb. nov.; and Kapraunia gen. nov., which includes K. schneideri (Stuercke & Freshwater) comb. nov. and three additional species.
A molecular phylogenetic and DNA barcode assessment of the tribe Pterosiphonieae (Ceramiales, Rhodophyta) emphasizing the Northeast Pacific
(Canadian Science Publishing, 2016) Savoie, Amanda, M.; Saunders, Gary, W.
Sequence data (COI-5P and rbcL) for North American members of the tribe Pterosiphonieae were compared with collections from around the world. Phylogenetic analyses resolved Pterosiphonia as polyphyletic and many species required transfer to other genera. In our analyses Pterosiphonia sensu stricto included only the type species P. cloiophylla (C. Agardh) Falkenberg and P. complanata (Clemente) Falkenberg, as well as the South African species P. stegengae sp. nov. A new genus, Xiphosiphonia gen. nov., was described for X. ardreana (Maggs & Hommersand) comb. nov., X. pennata (C. Agardh) comb. nov., and X. pinnulata (Kützing) comb. nov. Some Asian, European and North American species previously attributed to Pterosiphonia were transferred to Symphyocladia including S. baileyi (Harvey) comb. nov., S. dendroidea (Montagne) comb. nov., S. plumosa nom. nov. (for P. gracilis Kylin), and S. tanakae (S. Uwai & M. Masuda) comb. nov. We also described two new North American species, Symphyocladia brevicaulis sp. nov. and S. rosea sp. nov. Other species formed a well-supported clade for which the genus name Polyostea Ruprecht was resurrected. Included in Polyostea were P. arctica (J. Agardh) comb. nov., P. bipinnata (Postels & Ruprecht) Ruprecht, P. hamata (E.S. Sinova) comb. nov., and P. robusta (N.L. Gardner) comb. nov.
A revision of the genus Cryptonemia (Halymeniaceae, Rhodophyta) in Bermuda, western Atlantic Ocean, including five new species and C. bermudensis (Collins & M. Howe) comb. nov.
(Taylor and Francis, 2018) Schneider, Craig, W.; Lane, Christopher, E.; Saunders, Gary, W.
Cryptonemia specimens collected in Bermuda over the past two decades were analysed using gene sequences encoding the large subunit of the nuclear ribosomal DNA and the large subunit of RuBisCO as genetic markers to elucidate their phylogenetic positions. They were additionally subjected to morphological assessment and compared with historical collections from the islands. Six species are presently found in the flora including C. bermudensis comb. nov., based on Halymenia bermudensis, and the following five new species: C. abyssalis, C. antricola, C. atrocostalis, C. lacunicola and C. perparva. Of the eight species known in the western Atlantic flora prior to this study, none is found in Bermuda. Specimens reported in the islands in the 1900s attributed to C. crenulata and C. luxurians are representative of the new species, C. antricola and C. atrocostalis, respectively.
Assigning morphological variants of Fucus (Fucales, Phaeophyceae) in Canadian waters to recognized species using DNA barcoding
(Canadian Science Publishing, 2008) Kucera, Hana; Saunders, Gary, W.
The intertidal brown algal genus Fucus (Phaeophyceae) consists of individuals with a generally dichotomously branched habit. Morphological variability within species, combined with morphological similarity between species, renders field identification difficult. In light of recent taxonomic revisions, which reduced 10 taxa traditionally recognized in Canada to four species, we tested the utility of the DNA barcode (mitochondrial cytochrome oxidase 1, 5′) for assigning individuals to these species. We sequenced the DNA barcode for 125 specimens representing all morphologies recognized. We confirmed our results by sequencing the internal transcribed spacer region for 66 specimens. This is the first study to establish that the DNA barcode successfully assigns different morphologies of brown algae to known species as well as other single-gene molecular markers currently used. Furthermore, the results uncovered substantial phenotypic plasticity in Pacific Fucus distichus, from moss-like fragments embedded in estuarine mud, strap-like morphs on exposed rocky coasts, to “spiralis”-like morphs in the upper intertidal whereas phenotypic expression for this species was more restricted in the Atlantic.
Collections from the mesophytic zone off Bermuda reveal three species of Kallymeniaceae (Gigartinales, Rhodophyta) in genera with transoceanic distributions
(Wiley, 2018) Schneider, Craig, W.; Popolizio, Thea, R.; Saunders, Gary, W.
A molecular survey of red algae collected by technical divers and submersibles from 90 m in the mesophotic zone off the coast of Bermuda revealed three species assignable to the Kallymeniaceae. Two of the species are representative of recently described genera centered in the western Pacific in Australia and New Zealand, Austrokallymenia and Psaromenia and the third from the Mediterranean Sea and the eastern Atlantic, Nothokallymenia. A phylogenetic analysis of concatenated mitochondrial (COI-5P) and chloroplast (rbcL) genes, as well as morphological characteristics, revealed that two are shown to be new species with distant closest relatives (N. erosa and Psaromenia septentrionalis), while the third represents a deep water western Atlantic species now moved to an Australasian genus (A. westii).
Detecting Alaria esculenta and Laminaria digitata (Laminariales, Phaeophyceae) gametophytes in red algae, with consideration of distribution patterns in the intertidal zone
(Taylor and Francis, 2019) Bringloe, Trevor, T.; Bartlett, Charlotte, A.B.; Bergeron, Emma, S.; Cripps, Katherine, S.A.; Daigle, Nicole, J.; Gallagher, Patrick, O.; Gallant, Alicia, D.; Giberson, Rachel, O.J.; Greenough, Simon, J.; Lamb, Jillian, M.; Leonard, Thomas, W.; MacKay, Jane, A.; McKenzie, Alexander, D.; Persaud, Shana, M.; Sheng, Tianqi; Stack Mills, Alexa, M.E.; Moore, Tanya, E.; Saunders, Gary, W.
Kelp ecology is heavily biased toward the conspicuous sporophyte stage, whereas understanding of the microscopic gametophyte remains limited. Given that kelp gametophytes are known to grow in/on other species of algae, we sought to determine if species-specific polymerase chain reaction could detect kelp gametophytes in situ from coextracted host DNA. Upon verifying our molecular results, we also assessed distributional patterns of the kelp gametophytes according to site, host species, and vertical placement in the intertidal zone. We sampled Chondrus crispus, Mastocarpus stellatus, and Palmaria palmata (Florideophyceae) at Wallace Cove, New Brunswick, Canada, on 13 September 2016, where kelp sporophytes were abundant, and at an adjacent location without obvious sporophyte presence, L'Etete, on 26 September 2016. Species-specific primers were used to assess the presence of Alaria esculenta and Laminaria digitata DNA from coextracted red algal DNA. We successfully amplified kelp DNA from the host tissue of each red algal species, indicating that gametophytes were present at Wallace Cove and L'Etete during the fall of 2016, with significantly less gametophyte presence at L'Etete. Although no significant differences in gametophyte presence occurred according to host species, P. palmata had significantly less gametophyte presence when sampled from its upper range in the intertidal. Microscopy and additional field observations confirmed the presence of brown endophytes in a variety of hosts, including C. crispus and P. palmata. Our study showcases a simple method for detecting kelp gametophytes, with our preliminary results demonstrating that the distributional and ecological range of kelp gametophytes is broader than that of the sporophytic counterparts.
DNA barcoding reveals multiple overlooked Australian species of the red algal order Rhodymeniales (Florideophyceae), with resurrection of Halopeltis J. Agardh and description of Pseudohalopeltis gen. nov.
(Canadian Science Publishing, 2010) Saunders, Gary, W.; McDonald, Brian
The DNA barcode (COI-5P) was used to investigate cryptic diversity among Rhodymenia spp. in southern Australia. Whereas eight species are currently recognized, we uncovered ca. 20 genetic species groups, phylogenetically assigned to four genera in two families. Procumbent specimens with molecular and anatomical signatures of the Fryeellaceae are assigned to Pseudohalopeltis tasmanensis gen. et sp. nov. Collections from Lord Howe Island recorded in the field as Rhodymenia/Fauchea sp. are assigned to the poorly known genus Microphyllum as Microphyllum robustum sp. nov. A cluster of species with distinct molecular and anatomical attributes is included in a resurrected Halopeltis J.G. Agardh, including Halopeltis australis (J. Agardh) comb. nov. (type species); Halopeltis austrina (Womersley) comb. nov.; Halopeltis cuneata (Harvey) comb. nov. [including Rhodymenia halymenioides (J. Agardh) Womersley]; Halopeltis gracilis sp. nov.; Halopeltis prostrata sp. nov.; and Halopeltis verrucosa (Womersley) comb. nov. Four additional species of Halopeltis from Lord Howe Island (LH1, LH2), Tasmania (TAS), and Western Australia are not characterized further. For Rhodymenia sensu stricto, similar levels of cryptic diversity were noted. Samples tentatively field-identified as “Rhodymenia sonderi,” but having affiliations to Rhodymenia rather than Halopeltis, are referred to Rhodymenia novahollandica sp. nov. Collections field-identified as R. obtusa are genetically distinct from that species and are assigned to Rhodymenia wilsonis (Sonder) comb. nov. Two highly divergent species currently identified as Rhodymenia leptophylla (LH from Lord Howe Island; TAS from Tasmania), as well as two additional cryptic previously unnamed taxa from South Australia (SA) and Victoria (VIC), are not characterized further.
Evidence for the introduction of the Asian red alga Neosiphonia japonica and its introgression with Neosiphonia harveyi (Ceramiales, Rhodophyta) in the Northwest Atlantic
(Wiley, 2015) Savoie, Amanda, M.; Saunders, Gary, W.
There is currently conflict in the literature on the taxonomic status of the reportedly cosmopolitan species Neosiphonia harveyi, a common red alga along the coast of Atlantic Canada and New England, USA. Neosiphonia harveyi sensu lato was assessed using three molecular markers: COI-5P, ITS and rbcL. All three markers clearly delimited three genetic species groups within N. harveyi sensu lato in this region, which we identified as N. harveyi, N. japonica and Polysiphonia akkeshiensis (here resurrected from synonymy with N. japonica). Although Neosiphonia harveyi is considered by some authors to be introduced to the Atlantic from the western Pacific, it was only confirmed from the North Atlantic suggesting it is native to this area. In contrast, Neosiphonia japonica was collected from only two sites in Rhode Island, USA, as well as from its reported native range in Asia (South Korea), which when combined with data in GenBank indicates that this species was introduced to the Northwest Atlantic. The GenBank data further indicate that N. japonica was also introduced to North Carolina, Spain, Australia and New Zealand. Despite the fact that all three markers clearly delimited N. harveyi and N. japonica as distinct genetic species groups, the ITS sequences for some N. harveyi individuals displayed mixed patterns and additivity indicating introgression of nuclear DNA from N. japonica into N. harveyi in the Northwest Atlantic. Introgression of DNA from an introduced species to a native species (i.e. ‘genetic pollution’) is one of the possible consequences of species introductions, and we believe this is the first documented evidence for this phenomenon in red algae.
New species of Galene and Howella gen. nov. (Halymeniaceae, Rhodophyta) from the mesophotic zone off Bermuda
(Taylor and Francis, 2019) Schneider, Craig, W.; Popolizio, Thea, R.; Kraft, Lesleigh, G.K.; Saunders, Gary, W.
The mesophotic zone off the coast of Bermuda has been explored for macroalgae beginning with the R/V Seahawk cruises of the 1980s and most recently on the Nekton XL Catlin cruise of the R/V Baseline Explorer in 2016. In this paper, we present two new members of the Halymeniaceae discovered on these missions based upon a combined ML analysis of mitochondrial (COI-5P), plastid (rbcL) and nuclear genes (LSU), as well as morphological and anatomical characteristics. Howella gorgoniarum gen. et sp. nov. grows conspicuously on the base of soft corals, and represents one of the three species in the new genus. Two species of the non-monophyletic Thamnoclonium, T. latifrons Endlicher & Diesing and T. lemannianum Harvey from South Africa and Australia, are moved to Howella based upon their molecular phylogenetic placements. First collected offshore of Bermuda in 1960 and misidentified as Halymenia hancockii, Galene leptoclados sp. nov. represents the first species in its genus collected outside of the western Pacific.
On the nomenclatural reinstatement and lectotypification of Spyridia americana Durant (1850)
(De Gruyter, 2021) Schneider, Craig, W; Wynne, Michael, J; Saunders, Gary, W.
Southern New England and New York specimens of Spyridia ‘filamentosa’ were sequenced for the mitochondrial COI-5P and chloroplastic rbcL genes and determined to be distinct from Mediterranean (type locality) specimens of the same taxon. A little-known species name, S. americana Durant, is applied to specimens collected from the northeastern coast of the United States.
Trans-Arctic speciation of Florideophyceae (Rhodophyta) since the opening of the Bering Strait, with consideration of the “species pump” hypothesis
(Wiley, 2019) Bringloe, Trevor, T.; Saunders, Gary, W.
Aim The opening of the Bering Strait initiated significant biotic interchange that is postulated to have played a major role in phylogeographical patterns of northern marine flora and fauna. In addition, the “species pump” hypothesis asserts that glaciation events promoted speciation due to repeated isolation of populations over the past 2.6 million years. Here, trans-Arctic speciation events in red marine macroalgae (Florideophyceae) were assessed using time-calibrated phylogenies, and the applicability of the “species pump” hypothesis was considered. Location Species records and sequence data for trans-arctic genera of marine macroalgae were amalgamated and supplemented with sampling from the Northwest Atlantic, Northern Alaska (Beaufort Sea), Norway, and Nome, Alaska (Bering Sea; 2014–2017). Methods Bayesian and maximum likelihood phylogenies were variously built using the 5′ end of the cytochrome c oxidase subunit I gene (COI-5P), and/or the full-length nuclear internal transcribed spacer region (ITS), and/or the ribulose-1 5-biphosphate carboxylase large subunit gene (rbcL), and nodes were timed using calibrated COI-5P and rbcL molecular clocks. The final dataset represented approximately 184 species, broadly representing 14 trans-arctic lineages. Results Pacific to Atlantic migration and subsequent speciation was inferred in 11 cases, whereas the opposite scenario, atlantic to pacific, was inferred once; only three speciation events appeared to occur during the Pleistocene. Main conclusions Our results are in agreement with previous studies in that trans-arctic speciation events postdated the opening of the Bering Strait with a clear pacific to atlantic bias. Evidence for the “species pump” (as applied to trans-arctic interchange) was lacking given the frequency of trans-arctic speciation events was not amplified during the Pleistocene.

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