Collections from the mesophytic zone off Bermuda reveal three species of Kallymeniaceae (Gigartinales,Rhodophyta) in genera with transoceanic distributions

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).     

The monospecific genus Meredithia (Kallymeniaceae,Gigartinales) is species rich and geographically widespread with species from temperate Atlantic,Pacific, and Indian Oceans

Using sequences of 5′ region of the cytochrome oxidase subunit 1 gene, large subunit rDNA, and ribulose‐1,5‐bisphosphate carboxylase/oxygenase large subunit gene as genetic markers to elucidate their phylogenetic positions, six unknown species from Western Australia, Tasmania, Lord Howe Is., and Norfolk Is. cluster with Meredithia in the Kallymeniaceae (Gigartinales), and are described as new members of this previously monospecific genus. Specimens from Bermuda referable to Kallymenia limminghei Mont. in the 20th century also clustered with this genetic grouping, not with the generitype of Kallymenia. The Bermudian specimens are further shown to be morphologically distinct from the type of K. limminghei (Guadeloupe, Caribbean Sea) and are described as a new species, Meredithia crenata. Using these Indo‐Pacific and Bermudian collections, our analyses further show that Psaromenia is closely related to Meredithia, and that Cirrulicarpus nanus sensu stricto should be returned to Meredithia.     

A molecular evaluation of the Liagoraceae sensu lato (Nemaliales,Rhodophyta) in Bermuda including Liagora nesophila sp. nov. and Yamadaella grassyi sp. nov.

We have undertaken a comprehensive, molecular‐assisted alpha‐taxonomic examination of the rhodophyte family Liagoraceae sensu lato, a group that has not previously been targeted for molecular studies in the western Atlantic. Sequence data from three molecular markers indicate that in Bermuda alone there are 10 species in nine different genera. These include the addition of three genera to the flora — Hommersandiophycus, Trichogloeopsis, and Yamadaella. Liagora pectinata, a species with a type locality in Bermuda, is phylogenetically allied with Indo‐Pacific species of Hommersandiophycus, and the species historically reported as L. ceranoides for the islands is morphologically and genetically distinct from that taxon, and is herein described as L. nesophila sp. nov. Molecular sequence data have also uncovered the Indo‐Pacific L. mannarensis in Bermuda, a long‐distance new western Atlantic record. DNA sequences of Trichogloeopsis pedicellata from the type locality (Bahamas) match with local specimens demonstrating its presence in Bermuda. We described Yamadaella grassyi sp. nov. from Bermuda, a species phylogenetically and morphologically distinct from the generitype, Y. caenomyce of the Indo‐Pacific. Our data also indicated a single species each of Ganonema, Gloiocallis, Helminthocladia, Titanophycus, and Trichogloea in the flora.     

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.

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.     

Phylogeography of the Hypnea musciformis species complex (Gigartinales,Rhodophyta) with the recognition of cryptic species in the western Atlantic Ocean

Populations of the marine benthic red macroalgae Hypnea musciformis and Hypnea pseudomusciformis along the Atlantic and Pacific Oceans were tested for phylogeographic structure using the DNA barcode COI‐5P combined with rbcL for the construction of the phylogenetic tree. Strong patterns of genetic structure were detected across 210 COI‐5P DNA sequences, and 37 COI‐5P haplotypes were found, using multiple statistical approaches. Hypnea musciformis was found in the Northeast and Northwest Atlantic, the Mediterrean Sea, Namibia, and along the Pacific coast of Mexico. Two new putative species were detected, Hypnea sp. 1 in the Caribbean Sea and Hypnea sp. 2 in the Dominican Republic. Three distinct marine phylogeographic provinces were recognized in the Southern Hemisphere for H. pseudomusciformis: Uruguay, South‐Southeast Brazil, and Northeast Brazil. The degree of genetic isolation and distinctness among these provinces varied considerably. The Uruguay province was the most genetically distinct, as characterized by four unique haplotypes not shared with any of the Brazilian populations. Statistically significant results support both, isolation by distance and isolation by environment hypotheses, explaining the formation and mantainance of phylogeographic structuring along the Uruguay‐Brazil coast. Geographic, taxonomic and molecular marker concordances were found between our H. pseudomusciformis results and published studies. Furthermore, our data indicate that the Hawaiian introduced populations of H. musciformis contain Hypnea sp. 1 haplotypes, the current known distribution of which is restricted to the Caribbean.     

Polysiphonia freshwateri sp. nov. and Polysiphonia koreana sp. nov.: two new species of Polysiphonia (Rhodomelaceae,Rhodophyta) from Korea

Polysiphonia sensu lato comprises approximately 200 species, which are currently assigned to several different genera. To date, one of these genera, namely, Polysiphonia, has been reported to have 17 species. Here, we describe for the first time P. freshwateri sp. nov. and P. koreana sp. nov. from Uljin and Ulleung Island, Korea, based on morphological and molecular evidence. Polysiphonia freshwateri sp. nov. and P. koreana sp. nov. are characterized by having the typical Polysiphonia features. Polysiphonia freshwateri sp. nov. is further characterized by having abundant trichoblasts, conspicuous scar cells, and tetrasporangia arranged in spiral series. Polysiphonia koreana sp. nov. is further characterized by having very scarce scar cells placed between two pericentral cells, from which cicatrigenous branches arise. The results of our rbcL sequence analyses support the taxonomic placement of P. freshwateri sp. nov. and P. koreana sp. nov. within Polysiphonia.     

PCR fishing for red endophytes in British Columbia Kallymeniaceae (Gigartinales,Florideophyceae) uncovers the species‐rich Kallymenicola gen. nov. (Palmariales,Nemaliophycidae)

Unexpected contaminants uncovered during routine COI‐5P DNA barcoding of British Columbia Kallymeniaceae indicated the presence of a novel lineage allied to the family Meiodiscaceae, Palmariales. Available rbcL data for species of this family were used to design specific primers to screen for the presence of the meiodiscacean species in 534 kallymeniacean specimens primarily from British Columbia, Canada. Ultimately, 43 positive PCR products representing six diverse genetic groups from nine host species were uncovered; three are described here in the new genus Kallymenicola gen. nov., viz., K. invisiblis sp. nov., K penetrans sp. nov., and K superficialis sp. nov. Although genetic groups loosely displayed evidence of host specificity and cospeciation, examples of host switching with interesting biogeographical patterns were also documented.     

Melanothamnus maniticola sp. nov. (Ceramiales,Rhodophyta): an epizoic species evolved for living on the West Indian Manatee

Over 35 macroalgae have been documented growing epizoically on sea turtles, and macroalgae are also known to grow on the West Indian Manatee, but the number and identity of these latter species have not been determined. Analysis of DNA sequences of 12 samples collected from different manatees captured in three areas of Florida indicated that they represented a single undescribed species within the Rhodomelaceae genus Melanothamnus. Morphological analysis revealed Melanothamnus characteristics but also a previously undescribed combination of character states. These include eight to nine, but as many as 11, pericentral cells; heavy cortication restricted to the base of thalli, and a sharp transition between the corticated and ecorticate sections of the thallus; cells surrounding the ostiole being similar in size to the outer pericarp cells immediately below, and robust rhizoids that have no terminal lobes and develop from central axial cell filaments instead of pericentral cells. The unique characteristics of the rhizoids may be evolutionary adaptations for anchoring the thalli to manatee epidermis. This species is described as M. maniticola sp. nov.     

Morphology and ontogenesis of two new Hemiholosticha species (Ciliophora,Hypotrichia, Hemiholostichidae nov. fam.)

The morphology and ontogenesis of two new hypotrich ciliates, Hemiholosticha solitaria and Hemiholosticha germanica, were studied using live observation, protargol impregnation, and scanning electron microscopy. Both species share a medium-sized, almost globular body with a short anterior projection; two macronuclear nodules with a single micronucleus in between; a central contractile vacuole; three or four ventral, one postoral, one right and one left marginal cirral row; and three dorsal kineties extending along ribs. However, H. germanica is distinguished from congeners by a higher number of cirri in ventral rows R1 and R2 (3–6 vs. 2 cirri in each row). Hemiholosticha solitaria differs from congeners by having four (vs. three) ventral cirral rows and by the lack (vs. presence) of intracellular green algae. The ontogenesis of H. solitaria follows the H. pantanalensis mode in that (i) the oral primordium develops in a deep pouch and generates the first two cirral streaks in addition to adoral membranelles and undulating membranes, (ii) the undulating membrane anlage does not produce any cirri, and (iii) the longitudinal ventral cirral row R3 originates from two anlagen. The ontogenetic peculiarities along with the 18S rRNA gene phylogenies suggest classification of Hemiholosticha, Psilotrichides, and Urospinula into a new family, Hemiholostichidae.     

Molecular phylogeny of two unusual brown algae,Phaeostrophion irregulare and Platysiphon glacialis,proposal of the Stschapoviales ord. nov. and Platysiphonaceae fam. nov., and a re‐examination of divergence times for brown algal orders

The molecular phylogeny of brown algae was examined using concatenated DNA sequences of seven chloroplast and mitochondrial genes (atpB, psaA, psaB, psbA, psbC, rbcL, and cox1). The study was carried out mostly from unialgal cultures; we included Phaeostrophion irregulare and Platysiphon glacialis because their ordinal taxonomic positions were unclear. Overall, the molecular phylogeny agreed with previously published studies, however, Platysiphon clustered with Halosiphon and Stschapovia and was paraphyletic with the Tilopteridales. Platysiphon resembled Stschapovia in showing remarkable morphological changes between young and mature thalli. Platysiphon, Halosiphon and Stschapovia also shared parenchymatous, terete, erect thalli with assimilatory filaments in whorls or on the distal end. Based on these results, we proposed a new order Stschapoviales and a new family Platysiphonaceae. We proposed to include Phaeostrophion in the Sphacelariales, and we emended the order to include this foliose member. Finally, using basal taxa not included in earlier studies, the origin and divergence times for brown algae were re‐investigated. Results showed that the Phaeophyceae branched from Schizocladiophyceae ~260 Ma during the Permian Period. The early diverging brown algae had isomorphic life histories, whereas the derived taxa with heteromorphic life histories evolved 155–110 Ma when they branched from the basal taxa. Based on these results, we propose that the development of heteromorphic life histories and their success in the temperate and cold‐water regions was induced by the development of the remarkable seasonality caused by the breakup of Pangaea. Most brown algal orders had diverged by roughly 60 Ma, around the last mass extinction event during the Cretaceous Period, and therefore a drastic climate change might have triggered the divergence of brown algae.     

Drachiella liaoii sp. nov., a new member of the Schizoserideae (Delesseriaceae,Rhodophyta) from Taiwan and the Philippines

A new member of Delesseriaceae (Ceramiales, Rhodophyta) is described from Southern Taiwan and the Philippines. On the basis of comparative vegetative and reproductive morphology, and phylogenetic analysis inferred from nuclear-encoded large-subunit ribosomal DNA sequences (LSU rDNA), we conclude that it belongs in the genus Drachiella, tribe Schizoserideae, subfamily Phycodryoideae. The new taxon shares with other Drachiella species the absence of macro- and microscopic veins; diffuse growth by marginal and intercalary meristematic cells; a polystromatic, lobed thallus; abundance of rhizoidal marginal proliferations used for attachment; convoluted plastids in surface cells; abundant secondary pit connections among adjacent vegetative cells; large intercellular spaces between surface cells; procarps confined to the upper side of the thallus, circular in outline, consisting of a supporting cell bearing a strongly curved carpogonial branch and two sterile groups that remain undivided; vertical division of gonimoblast initial from auxiliary cell, and unilateral, monopodial branching of gonimoblasts; and mature cystocarps with a massive candelabrum-like fusion cell of fused gonimoblasts bearing carposporangia in branched chains. It is distinguished from the other members of the genus by thalli that consist of extensive tangled mats of prostrate and overlapping decumbent blades, procarps confined to the upper side of the thallus, and the lack of basal stalks or stipes. Whereas the Schizoserideae is predominantly a Southern Ocean tribe, one of the tribe's four genera, Drachiella, was known only from the eastern Atlantic and Mediterranean. We herein report the first record of the genus for the Indo-Pacific Ocean, and describe Drachiella liaoii, sp. nov., as a fourth species in the genus.     

Systematic revision of the genus Phycodrys (Delesseriaceae,Rhodophyta) from New Zealand,with the descriptions of three new species,P. novae-zelandiae sp. nov., P. franiae sp. nov. and P. adamsiae sp. nov.

Two species of Phycodrys, Phycodrys quercifolia (Bory) Skottsberg and Phycodrys profunda E.Y.Dawson were previously recorded from New Zealand. However, an examination of Phycodrys collections from the New Zealand region showed that all were morphologically different from P. quercifolia (Type locality: the Falkland Islands) and P. profunda (Type locality: CA, USA). RbcL sequence analyses established that the New Zealand Phycodrys species formed a natural assemblage within the genus, consisting of three new species: P. novae-zelandiae sp. nov., P. franiae sp. nov. and P. adamsiae sp. nov. Phycodrys novae-zelandiae is the largest of the three, up to 20 cm in height, with a distinct midrib and multicellular, opposite to subopposite lateral macroscopic veins. It has entirely monostromatic blades except near the midrib and veins, and its procarp contains a three-celled sterile group one (st1) and a one-celled sterile group two (st2). Phycodrys franiae was previously treated as a cryptic species among herbarium collections of P. ‘quercifolia’. It is smaller (4–11 cm high) with weakly developed midribs and veins, the blade is tristromatic throughout, except at the growing margins, and the procarp consists of a four-celled st1 and a two–three-celled st2. Phycodrys adamsiae, previously reported as P. profunda, is a small decumbent or prostrate plant, 1–8 cm long, with a midrib and inconspicuous lateral veins. The blades are tristromatic with serrated margins, two–four-celled surface spines and multicellular marginal holdfasts that differ from those of Californian specimens. The tetrasporangia are borne on marginal bladelets. Phylogenetic analyses place the New Zealand species in a separate group that is distantly removed from most other Phycodrys species.     

Dasya adela sp. nov. (Rhodophyta,Ceramiales), an enigmatic new Dasya from a landlocked fjord in southwest Norway

We here report a new Dasya species found in a landlocked fjord or poll in southwestern Norway; Dasya adela sp. nov. The thallus of this species is small (1–3 cm), normally sparsely branched, and its axes are completely covered with cortex cells. The species is set with long (3–4 mm) and flaccid monosiphonous pseudolaterals, and during autumn it showed high growth of adventitious monosiphonous branches. Only a few individuals with tetrasporangia have been recorded, and no sexual reproductive structures have been observed in field collections. In culture stichidia readily developed on the pseudolaterals, with four tetrasporangia per section. The spores showed high mortality. A few sporelings survived in culture, and developed into small and loosely organized filaments with no upright axes. After 2 years in culture a few plants bearing spermatangial branches were observed, but no individuals with carpogonia. The monosiphonous branches are readily shed in culture, attach themselves by rhizoids and rapidly develop into new thalli, some of which have produced tetrasporangial stichidia. Sequences analyses of partial COI and the rbc L gene showed that the new taxon belongs within Dasyoideae. However, no close relationship was found with other European species of Dasya. The new taxon was compared to other Dasya taxa with which it shared a number of selected characters, but none of these taxa shared all characters of the new Dasya.     

Crusticorallina gen. nov., a nongeniculate genus in the subfamily Corallinoideae (Corallinales,Rhodophyta)

Molecular phylogenetic analyses of 18S rDNA (SSU) gene sequences confirm the placement of Crusticorallina gen. nov. in Corallinoideae, the first nongeniculate genus in an otherwise geniculate subfamily. Crusticorallina is distinguished from all other coralline genera by the following suite of morpho‐anatomical characters: (i) sunken, uniporate gametangial and bi/tetrasporangial conceptacles, (ii) cells linked by cell fusions, not secondary pit connections, (iii) an epithallus of 1 or 2 cell layers, (iv) a hypothallus that occupies 50% or more of the total thallus thickness, (v) elongate meristematic cells, and (vi) trichocytes absent. Four species are recognized based on rbcL, psbA and COI‐5P sequences, C. painei sp. nov., the generitype, C. adhaerens sp. nov., C. nootkana sp. nov. and C. muricata comb. nov., previously known as Pseudolithophyllum muricatum. Type material of Lithophyllum muricatum, basionym of C. muricata, in TRH comprises at least two taxa, and therefore we accept the previously designated lectotype specimen in UC that we sequenced to confirm its identity. Crusticorallina species are very difficult to distinguish using morpho‐anatomical and/or habitat characters, although at specific sites, some species may be distinguished by a combination of morpho‐anatomy, habitat and biogeography. The Northeast Pacific now boasts six coralline endemic genera, far more than any other region of the world.     

Molecular and morphological evidence for Sheathia gen. nov. (Batrachospermales,Rhodophyta) and three new species

The freshwater red algal genus Batrachospermum has been shown to be paraphyletic since the first molecular studies of the Batrachospermales. Previous research, along with this study, provides strong support for the clade Batrachospermum section Helminthoidea. This study has found that heterocortication, the presence of both cylindrical and bulbous cells on the main axis, is an underlying synapomorphy of this clade. Based on support from DNA sequences of the rbcL gene, the COI barcode region and the rDNA ITS 1 and 2, along with morphological studies, the new genus Sheathia is proposed. Seven heterocorticate species were recognized from the molecular clades. Sheathia boryana and S. exigua sp. nov. appear to be restricted to Europe, whereas S. confusa occurs in Europe and New Zealand. Sheathia involuta is widespread in the USA and reported for the first time from Europe. Sheathia americana sp. nov., has been collected in the USA and Canada, and S. heterocortica and S. grandis sp. nov. have been collected only in the USA. Sheathia confusa and S. grandis can be distinguished based on morphological characters, whereas DNA sequence data are required to conclusively distinguish the other species. Sheathia fluitans and S. carpoinvolucra also are placed within this genus based on the presence of heterocortication. These data also hint at greater diversity among non‐heterocorticate Sheathia than is recognized by the single species name S. arcuata.