rbcL Sequence Analysis Research Articles

Coralline red algal species diversity at a shallow rhodolith bed in warm-temperate Japan, including two new species of Roseolithon (Hapalidiales, Corallinophycidae)

ABSTRACT A shallow rhodolith bed at Shirasu, approximately 1 m deep, is the largest rhodolith bed, emergent only at spring low tides, in warm-temperate Japan. Using phylogenetic analyses of psbA, rbcL and COI-5P sequences, at least 10 species of rhodolith forming, non-geniculate coralline algae were documented. In the Corallinales, three previously reported Lithophyllum species: L. okamurae, L. neo-okamurae and L. nagaokaense were found. The remaining seven taxa comprised species of Hapalidiales, with Tectolithon sp. and Crustaphytum sp. sister to Tectolithon fluminense from Brazil and Crustaphytum taoyuanense from Taiwan, respectively. Three undescribed Hapalidiales spp. 1–3 were each resolved in distinct lineages. The remaining two species are herein newly described as Roseolithon littorale sp. nov. and R. sabulosum sp. nov. Morpho-anatomically, these two Japanese Roseolithon species are nearly indistinguishable from each other and from closely related taxa. The two Japanese Roseolithon species differed only by the degree of degeneration of their tetra/bisporangial conceptacle rosette cells. Roseolithon littorale differed from R. tamoioi from Brazil by the number of roof cells, and by the number and appearance of cells lining the pore canals. Roseolithon sabulosum differed from R. indicum from Australia in having in average smaller tetra/bisporangial conceptacle chamber dimensions. This study highlighted the underestimated rhodolith diversity in Japan along with the extended distributions of Crustaphytum, Tectolithon and Roseolithon species to the warm-temperate northwestern Pacific region.

Eastward spreading of the invasive Rugulopteryx okamurae (Heterokontophyta, Dictyotales) in the Mediterranean: first record in the Adriatic Sea

The brown seaweed Rugulopteryx okamurae is currently included in the list of invasive alien species of European Union concern due to its rapid expansion that is causing both ecological and economic impacts. In this study, we report the first record of R. okamurae in the Southern Adriatic Sea, off the coast of Bari, Italy, currently representing the easternmost limit of its distribution in the Mediterranean Sea. Morphological observations combined with rbcL and psbA sequence analyses confirmed the taxonomic identification. Field surveys carried out between April 2023 and January 2024 highlighted the conspicuous occurrence of R. okamurae over a total surface of approximately 6.5 ha. Two main human-mediated pathways occurring near the sites of the first observation of the alien species may have been responsible for its introduction: the trade in living organisms for human consumption and maritime transport related to the proximity of the port of Bari to the invaded area. Future studies will aim to identify and implement practical, cost-effective management strategies to mitigate this alarming bioinvasion.

Description of Callophyllis eduardii sp. nov. (Rhodophyta, Kallymeniaceae) from eastern Russia

ABSTRACT A new species of Callophyllis from Peter the Great Bay, Sea of Japan, Russia, is recognized based on the morphological and molecular analyses of rbcL and nrLSU sequences. We name this new species C. eduardii sp. nov. Phylogenetic analysis suggests that C. eduardii is distinct from other Callophyllis species and sister to a diverse group that includes monocarpogonial species from the northeastern Pacific and species from the Russian Pacific coast. Callophyllis eduardii is characterized by diminutive thalli, narrow anastomosing branches with acute apices and smooth margins and cystocarps, without an ostiole, scattered over the blade and at the margins in the middle and upper part of the thallus. This is the ninth species of the genus found in Russian waters.

Species diversity and molecular phylogeny of Crustaphytum and Mesophyllum (Hapalidiales, Rhodophyta) from the Asian Pacific, including three new species of Crustaphytum

ABSTRACTThe non-geniculate coralline algal genus Crustaphytum occurs in subtropical regions of the Pacific and Atlantic Oceans and presently contains only two species, C. pacificum and C. atlanticum. In contrast, the genus Mesophyllum is more widely reported and has representative species in both warm and cold waters. We analysed the species diversity of collections of Crustaphytum and Mesophyllum-like specimens from the Asian-Pacific region, based on psbA and rbcL sequence analyses and morphology. Our molecular analyses showed that the collections of Mesophyllum-like specimens mostly belonged to Crustaphytum with only a few specimens clustering with the Mesophyllum/Melyvonnea complex. We also describe three new species of Crustaphytum (C. taiwani-boreale sp. nov., C. taoyuanense sp. nov. and C. fragile sp. nov.) that are commonly found in the algal reefs in Northwest Taiwan, utilizing both scanning electron and light microscopy, and DNA sequence analyses. Crustaphytum fragile (79–95 μm thick) and Crustaphytum taiwani-boreale (235–436 μm thick) mostly grow in similar habitats in the algal reefs and can only be distinguished by a combination of characters relating to tetrasporangial chamber size and the number of cell layers in the cortex and medulla. Crustaphytum taoyuanense (233–300 μm thick) can be separated from the other species by its violet-red colour and by the margins of older thalli becoming overgrown by adjacent thalli. Crustaphytum taoyuanense and C. fragile are restricted to Taoyuan City in Northwestern Taiwan, whereas C. taiwani-boreale has a broader distribution in Northern Taiwan. Our study reveals a rich species diversity of Crustaphytum in the warm water region of the Western Pacific Ocean.

Systematic revision of the Grateloupia complex (Rhodophyta) from Vietnam using rbcL and LSU sequences, with the description of Phyllymenia nhatrangensis sp. nov.

ABSTRACT Grateloupia sensu lato has had a long and troublesome taxonomic history because of superficial similarities in morphology, ill-defined species boundaries and lack of diagnostic characters that leave many gaps that still need to be fully resolved. In this study, we carried out detailed observations on female reproductive structures, and inferred the phylogenetic relationships of the Grateloupia-like species occurring in Vietnam based on rbcL and LSU rDNA sequence analyses. The new species Phyllymenia nhatrangensis sp. nov. differs from its sister species P. gibbesii in the thickness of the cortex. The new species is slightly flattened, composed of two to four main blades, bearing numerous marginal and a few superficial, lanceolate bladelets. Blade sizes of P. nhatrangensis are also smaller than those of P. gibbesii, which are longer and wider. However, the new species shares with species from western Pacific Ocean, such as P. taiwanensis and P. huangiae, the presence of frequent marginal proliferations. Based on rbcL, the divergence between P. nhatrangensis and P. gibbesii was 3.3% (39 bp). With the present addition, Grateloupia sensu lato now comprises 16 species, including nine species of Grateloupia, three species of Phyllymenia, two species of Yonagunia and one species each of Dermocorynus and Prionitis.

Independent, structurally distinct transitions to microfruticose growth in the crustose genus Porina (Ostropales, Lecanoromycetes): new isidioid species from south-western Florida

AbstractPorina is a widely distributed, species-rich genus of crustose, lichen-forming fungi, some with thalline outgrowths that have been recognized as isidia. We studied three taxa with thalli consisting chiefly of ascending isidioid structures occurring on trunks and branches of Taxodium in southwestern Florida, and provide details of their structure with light and electron microscopy. Two of these taxa we describe as new species: P. microcoralloides and P. nanoarbuscula. Genetic sequences (mtSSU) suggest that they are closely related to each other, yet they differ markedly in the size, morphology and anatomical organization of their isidioid branches as well as in the length of their ascospores. In the three Floridian taxa studied, the crustose portion of the thallus is partly endophloeodic and partly superficial, the latter often patchy, evanescent or inconspicuous, and completely lacks the differentiated anatomical organization characteristic of the isidioid structures arising from it. In Porina microcoralloides, the ascendant thallus consists of branched, coralloid inflated structures with phycobiont (Trentepohlia) unicells arranged at the periphery of a loose central medulla. Sparse fungal cells are interspersed and overlie the algal layer in places, but no differentiated cortex is present, leaving phycobiont cells more or less exposed at the surface. In the closely related Porina nanoarbuscula, the isidioid structures are much finer, more densely branched, and composed of a single, central file of roughly spherical Trentepohlia cells surrounded by a jacket of subglobose fungal cells. The ascospores of P. microcoralloides are more than twice the length of those of P. nanoarbuscula. Although thalli of these two Porina species occur in the same habitats and are sometimes found growing alongside each other, phylogenetic analysis of rbcL sequences suggest that they partner with distinct clades of Trentepohlia phycobionts. A third taxon examined, Porina cf. scabrida, is morphologically rather similar to P. microcoralloides, but the ascendant branches are bright yellow-orange, more cylindrical, and corticated by a thin layer of agglutinated fungal hyphae; perithecia were not seen. Analysis of mtSSU sequences places it distant from P. microcoralloides and P. nanoarbuscula phylogenetically. None of the Floridian taxa studied was particularly close to the European isidiate species Porina hibernica and P. pseudohibernica, which appeared as sister to each other in the analysis. While a particular type of isidiose structure may be reliably characteristic of specific taxa, similarities or differences in these structures do not seem to be useful indicators of phylogenetic proximity or distances among taxa. The morphological trends evident in Porina suggest that multiple transitions from crustose to isidioid or microfruticose growth have arisen repeatedly and in quite different ways within this single genus. At least some of the diverse structures treated within the broad concept of isidia may be representative of the developmental pathways by which fruticose growth forms may arise.

Asia Pacific Sporolithon (Corallinophycidae, Rhodophyta) species revised based on DNA sequencing of type specimens and including S. crypticum sp. nov., S. immotum sp. nov. and S. nodosum sp. nov.

ABSTRACTTo address the taxonomic uncertainty of Sporolithon species named in the early to mid-20th century, targeted PCR sequencing was performed on eight historical type specimens and on recently collected specimens. Six type specimens amplified for the rbcL gene and were Sanger sequenced yielding sequences ranging in length from 118 to 280 base pairs (bp). One, S. australasicum, failed to amplify and another, S. howei, was amplified for the psbA gene yielding a sequence 544 bp in length. The 118 bp long rbcL sequence of the lectotype of S. crassiramosum showed that it is a later, heterotypic synonym of S. molle. The rbcL sequences of type specimens of S. episoredion, S. schmidtii, S. sibogae and S. timorense ranged from 118 to 228 bp, and each is a distinct species. The 544 bp long psbA sequence of S. howei is also unique. The 280 bp long rbcL sequence of the lectotype of S. durum did not match any sequence with that name in any public repository, including the previously published complete plastome and mitogenome sequences. However, it was identical in sequence to a specimen in GenBank from the southern coast of Western Australia as well as several other sequences generated from field-collected specimens from the states of South Australia and Western Australia. The rhodolith specimens from New Zealand previously called S. durum are S. nodosum sp. nov. The species is endemic to New Zealand. The epilithic specimens from New Zealand previously called S. durum are S. immotum sp. nov., which is also found along the southeastern coast of Australia. Sporolithon crypticum sp. nov. is described from the southern coast of Western Australia. RAxML and Bayesian phylogenetic analyses of Sporolithon psbA and rbcL sequences are congruent between the two plastid encoded genes. DNA sequencing of type specimens of species of corallines is demonstrated to be the only reliable method to correctly apply names.

Germling culture and molecular analysis of evasive micro-filamentous green algae growing in the Maltese islands (central Mediterranean)

Abstract Various species of marine micro-filamentous green algae (<5 mm) remain overlooked globally. They are difficult to identify in field collections due to their diminutive size and their cryptic morphology. During this study, algal cultures combined with DNA barcoding helped to overcome these challenges. Both substratum samples and macrophytic fragments of Posidonia oceanica, Dictyopteris sp. and Halopteris sp. were incubated in laboratory culture. Germlings of Ulvella endostraca and Blastophysa rhizopus grew from the incubated substratum. Blastophysa rhizopus is a new record for the Maltese islands, as is U. endostraca that had only been reported previously from New Zealand. In situ, germlings of both species were also observed to grow as epiphytes, on Dictyopteris sp. in the case of U. endostraca, and on P. oceanica in the case of B. rhizopus. This study employed the in vitro culture of algal germlings, as well as morphological and molecular analyses. DNA data and subsequent phylogenetic analyses of tufA and rbcL sequences supported the separation of U. endostraca from other closely related congeners that have been previously reported from the Maltese islands. Moreover, this study includes a comparison of the micro-filamentous algae identified from Malta with those from other areas of the Mediterranean Sea.

Molecular phylogeny of foliose Halymenia and Austroepiphloea (Halymeniaceae, Rhodophyta) from the Indo-Pacific, with the description of Halymenia taiwanensis sp. nov.

ABSTRACT Many species of Halymenia from the Indo-Pacific have been described in the past decade, but their phylogenetic relationships are not well discussed. In this study, we inferred these relationships for the available species of Halymenia with an emphasis on the foliose species from the western Pacific Ocean and Western Australia based on rbcL and nuclear-encoded LSU rDNA sequence analyses. Our analyses show that most foliose Halymenia from the Indo-Pacific are clustered in a natural assemblage that also includes a new species (Halymenia taiwanensis sp. nov.) found in northern Taiwan, as well as the monospecific genus Austroepiphloea (single species A. bullosa) from Western Australia. The architecture of carpogonial branch (composed of a two-celled carpogonial branch and two orders of ampullar filaments, and a basal, nutritive cellular cluster) and auxiliary cell ampullae in Halymenia taiwanensis is similar to that found in the generitype H. floresii. We therefore propose the new combination Halymenia bullosa comb. nov. (basionym Schizymenia. bullosa), a species closely related to H. taiwanensis both genetically and morphologically. However, H. taiwanensis can be separated from H. bullosa by its thinner blades and surface bladelets, and by lacking a long cartilaginous stipe. Based on the rbcL phylogeny, most foliose Halymenia are seemingly more range-restricted than previously thought, except for a few species that are shown to have a wide distribution in the Western Pacific and Indian Oceans. In addition, H. dilatata, a species widely recorded in the Western Pacific Ocean, may include cryptic species and requires further investigation.

Systematic revision of the red algal genus Yonagunia (Halymeniaceae, Rhodophyta) from Taiwan, including the description of two new species

ABSTRACT Among the eight species of Yonagunia described in the Indo-Pacific region, five species have been reported from Taiwan. In this study, we re-examined additional herbarium specimens which were morphologically similar to the other Taiwanese species of Yonagunia. Two new species of Yonagunia (Y. robusta sp. nov. and Y. stipitata sp. nov.) were identified based on rbcL sequence analyses, and their vegetative and reproductive structures were documented in detail. Yonagunia robusta is the largest species (up to 13 cm high) found in Taiwan and superficially resembles a previously described species, Y. palmata from northern Taiwan, but the thallus size is much larger and the branches are coarser in Y. robusta. Young plants of Y. stipitata may be confused with Y. maillardii, a species widely distributed in the Indo-Pacific, but the thallus branches are much thinner and numerous reproductive branchlets are formed in clusters in fertile Y. stipitata. Yonagunia robusta is widely distributed from northern to south-eastern Taiwan, whereas Y. stipitata is restricted to Orchid Island, a remote small island off the south-east of Taiwan. The species diversity (seven out of 10 described species) of Yonagunia is high in Taiwan and it is speculated that some more cryptic species will be found from the Indo-Pacific by using a combination of DNA sequence data and morphological observations. HIGHLIGHTS Ten species of Yonagunia have been described from the Indo-Pacific. Seven out of 10 species of Yonagunia are found in Taiwan. Cryptic species of Yonagunia will be found in the Indo-Pacific.

Revisiting the systematics of the genera Grateloupia, Phyllymenia, and Prionitis (Halymeniaceae, Rhodophyta) with a description of a new species-Prionitis taiwani-borealis.

The taxonomy of the genera Grateloupia, Phyllymenia, and Prionitis has been revised several times but remains controversial. The anatomy of female reproductive structures in combination with phylogenetic reconstructions is mostly used to define the genera. However, the architecture and behavior of the auxiliary cell ampullae before and after diploidization are not well documented for most species. To fill this knowledge gap, we examined the female reproductive structures of a new species (Prionitis taiwani-borealis sp. nov.) from Taiwan and compared our observations to the species currently placed in the Phyllymenia/Prionitis complex. The female reproductive structures of the Phyllymenia/Prionitis complex are characterized by (1) 2-celled carpogonial branches with the supporting cell being the basal cell of a third-order ampullar filament; (2) auxiliary cell ampullae composed of three orders of unbranched ampullar filaments before diploidization; (3) cells of auxiliary cell ampullar filaments forming a cellular cluster after diploidization and surrounding the developing gonimoblasts; (4) gonimoblast initials produced from the diploidized auxiliary cells before fusing with them; and (5) branched auxiliary cell ampullar and secondary medullary filaments involved in early pericarp formation. A monophyletic relationship of species possessing female structures similar to those of Pr. taiwani-borealis and related species was highly supported based on combined rbcL and LSU rDNA sequence analyses. The female reproductive structures of other species of Grateloupia sensu lato, phylogenetically closely related to the Prionitis and Phyllymenia assemblage, require reinvestigation as correct interpretations of pre- and post-fertilization events have proven to be informative for resolving the systematics of the Halymeniaceae.

A new species of the genus Sheathia (Batrachospermaceae, Rhodophyta) from Japan

ABSTRACT We describe herein a new species of Sheathia from Chiba Prefecture, Japan (previously attributed to S. arcuata) based on morphological studies and molecular analyses of rbcL and COI-5P DNA sequences. We assign the binomial Sheathia yoshizakii sp. nov. to this new entity. The rbcL and COI-5P analyses suggest that S. yoshizakii is distinct from other Sheathia species. Sheathia yoshizakii is characterized by homocortication, a carpogonium with clavate to lanceolate trichogyne, and exerted carposporophytes. Although S. yoshizakii is distinguished from other Sheathia species by rare production of secondary fascicle and relatively long carpogonial branch, more than seven carposporophytes per whorl, and frequently exerted carposporophytes, these morphological characters are variable and consistent with the general circumscription of S. arcuata. Sheathia yoshizakii is the first Sheathia species confirmed by DNA sequence data in Japan.

Ethelia hawaiiensis (Etheliaceae, Rhodophyta), a New Mesophotic Marine Alga from Manawai (Pearl and Hermes Atoll), Papahānaumokuākea Marine National Monument, Hawai‘i1

A new species of mesophotic marine red algae, Ethelia hawaiiensis sp. nov., is illustrated and described. Ethelia hawaiiensis is distinguished from other members of the genus by its large diameter assurgent filament cells, and in having thallus cavities that are frequently inhabited by microalgae, as well as in DNA sequence. Analyses of mitochondrial COI, plastid rbcL, and nuclear SSU sequences demonstrated that E. hawaiiensis was distinct from other species of Ethelia and that it was not phylogenetically closely related to other known species. Both COI and rbcL analyses placed E. hawaiiensis within a clade of other Ethelia sequences, while the SSU analyses, which only included two previously described species of Ethelia, resolved E. hawaiiensis as sister to a clade comprising Ethelia plus the Peyssonneliales. Morphological differences between E. hawaiiensis and other members of the genus are discussed.

Genetic relationship analysis of Dendrobium anosmum Lindl. var. semialba based on the chloroplast matK and rbcL genes

Dendrobium anosmum Lindl. var. semialba has variants of flower shapes. Currently, it has high economic value and is favored on the market. In this study, the genetic relationship of Dendrobium anosmum Lindl. var. semialba species was determined based on the analysis of chloroplast matK, rbcL gene sequences. The matK and rbcL genes of twelve species were amplified and their DNA sequenced. These DNA sequences were compared, calculated genetic distance and constructed phylogenetic tree. The results showed that 100% of samples were amplified and sequenced successfully. The analysis of matK sequences showed that 12 species had very high genetic similarity with the low genetic distance of 0 - 0.001; the nucleotide sequences were almost unchanged except for one variable nucleotide position in TB1 and TB1 was in a separate branch of the phylogenetic tree. The analysis of rbcL sequences showed that all species had a low genetic distance of 0 - 0.012 and had 7 mutant positions in nucleotide sequences of TB1 and TB5. These species were in a separate branch of the phylogenetic tree while the other species were grouped in the other branch of the phylogenetic tree. The study provided a reliable molecular database of the Dendrobium anosmum Lindl. var. semialba for identification, classification, biodiversity assessment and conservation of genetic resources.

DNA sequencing of type material and newly collected specimens reveals two heterotypic synonyms for Harveylithon munitum (Metagoniolithoideae, Corallinales, Rhodophyta) and three new species.

Nongeniculate coralline algae are difficult to identify based solely on morpho-anatomy. To address the systematics of several taxonomically challenging taxa, we analyzed DNA sequences of a short portion (118-296 base pairs) of the 3' end of the rbcL gene from three type specimens. The analyses revealed that Harveylithon munitum (basionym: Lithophyllum munitum), described in 1906 from Cave Cays, Exuma Chain, Bahamas, is conspecific with both Goniolithon accretum and Goniolithon affine, described in 1906 from Sand Key, Florida and in 1907 from Culebra Island, Puerto Rico, respectively. Lithophyllum munitum and G.accretum were described in the same 1906 publication and have equal priority. We have selected the currently accepted and most commonly used name H.munitum to apply to this entity. Comparative analyses of rbcL, psbA, UPA, COI, and LSU sequences from contemporary field-collected specimens revealed that H.munitum currently inhabits mesophotic rhodolith beds in the northwestern Gulf of Mexico, as well as the intertidal zone in the Florida Keys, Honduras, Atlantic Mexico, Caribbean Panama, and Guadeloupe, French West Indies. Species delimitation analyses reveal that the Western Atlantic and Australian H.munitum populations may be separate species. Two new species of Harveylithon from the northwestern Gulf of Mexico and one new species from the southwestern Gulf of Mexico, the Caribbean, and the Red Sea were also identified in the analyses and are described.

Identification of Cannabis Sativa L. Based on rbcL Sequence.

Objective To assess the feasibility of the rbcL sequence of chloroplast DNA as a genetic marker to identify Cannabis sativa L. Methods The rbcL sequences in 62 Cannabis sativa L. samples, 10 Humulus lupulus samples and 10 Humulus scandens DNA samples were detected, and 96 rbcL sequences of the Cannabaceae family were downloaded from Genbank. Sequence alignment was performed by MEGA X software, the intraspecific and interspecific Kimura-2-Parameter （K2P） genetic distances were calculated, and the system clustering tree was constructed. Results The rbcL sequence length acquired by sequencing of Cannabis sativa L. and Humulus scandens were 617 bp and 649 bp, respectively, and two haplotypes of Cannabis sativa L. were observed in the samples. The BLAST similarity search results showed that the highest similarity between the sequences acquired by sequencing and Cannabis sativa L. rbcL sequences available from Genbank was 100%. The genetic distance analysis showed that the maximum intraspecific genetic distance （0.004 9） of Cannabis sativa L. was less than the minimum interspecific genetic distance （0.012 9）. The results of median-joining network and system clustering tree analysis showed that Cannabis sativa L. and other members of the Cannabaceae family were located in different branches. Conclusion The rbcL sequence could be used as a DNA barcode for identifying Cannabis sativa L., and combined with comparative analysis of the rbcL sequence and system cluster analysis could be a reliable and effective detection method for Cannabis sativa L. identification in forensic investigation.

A new flattened species of Gracilariopsis (Gracilariales, Rhodophyta) from Japan

ABSTRACT A new flattened species of Gracilariopsis from Mageshima Island, Japan is recognized based on morphological and molecular analyses of rbcL and cox1 DNA sequences. We name this new species Gp. mageshimensis sp. nov. The rbcL and cox1 analyses suggest that Gp. mageshimensis belongs to the Gracilariopsis clade, and that it is distinct from other Gracilariopsis species. Gracilariopsis mageshimensis is characterized by a flattened thallus, the lack of tubular nutritive cells, the lower gonimoblasts connect to the cystocarp floor cells via pit connections and small gonimoblasts filling the cystocarp cavity. The Gp. mageshimensis cystocarp is in accordance with the morphological concept of Gracilariopsis. Gracilariopsis mageshimensis is the second Gracilariopsis species with a flattened thallus to be described worldwide. Gracilariopsis mageshimensis is distinguished from Gp. silvana, the first flattened species by the rare production of lateral branches, a medulla consisting of fewer than five layers, and its deep-water habitat.

DNA Sequence Analyses Reveal Two New Species of Caloglossa (Delesseriaceae, Rhodophyta) from the Skin of West Indian Manatees

Epizoic macroalgae collected from the skin of West Indian manatees included specimens of the red algal family Delesseriaceae. Morphological and rbcL sequence analyses indicated that these specimens represented two novel species of Caloglossa. One species, described here as Caloglossa kamiyana Freshwater, Cath.E. Miller & Frankovich sp. nov., had been previously studied and recognized as part of the C. ogasawaraensis species complex. The rbcL sequence divergence between C. kamiyana and other taxa within the complex ranged from 4.6–5.3%, and tetrasporangial mother cells are cut off from the lateral pericentral cells by oblique divisions instead of transverse divisions as in C. ogasawaraensis. The second species was resolved as a closely related sister species to C. fluviatilis, with a minimum interspecific sequence divergence of 2.0%. It was morphologically indistinguishable from C. fluviatilis except for one potential character—mostly one, instead of multiple rhizoids, developing from rhizoid-bearing pericentral and marginal wing cells. It is herein described as Caloglossa manaticola Freshwater, Cath.E. Miller & Frankovich sp. nov.

New insights into the phylogeny of Spyridia (Ceramiales, Rhodophyta) species with uncinate spines, focusing on the structure of determinate branches

ABSTRACT Twenty-one samples belonging to species of Spyridia Harvey with uncinate (= hook-shaped) spines on determinate lateral branches were investigated for their morphology with a focus on the structure of determinate branches, and for comparative chloroplast-encoded rbcL and nuclear LSU rDNA sequence analysis to elucidate their taxonomy and phylogeny. Currently, four Spyridia species with uncinate spines are recognized worldwide: S. alternans, S. cupressina, S. horridula and S. hypnoides. Of them, S. hypnoides has been recognized as the most common species with uncinate spines. In this study, we show that S. aculeata needs to be resurrected from S. hypnoides, and recognized as a distinct species based on samples from Israel, Red Sea, near the type locality. Spyridia aculeata is characterized by the spiral arrangement of determinate branches, incompletely corticated determinate branches, naked basal segment of determinate branches, by the presence of only acropetal cortication in the nodes of determinate branches, and by uncinate spines at the terminal node and on the first and second nodes of determinate branches. In our molecular analyses based on rbcL and LSU rDNA, although four Spyridia species with uncinate spines are supported on phylogenetic trees, they are not a monophyletic group. The feature of uncinate spines in Spyridia is recognized as a polyphyletic character. Our phylogenetic analysis using rbcL and LSU rDNA sequences reveals high gene sequence divergence (6.8–7.0% for rbcL and 1.2–1.3% for LSU rDNA) between samples of S. aculeata and S. hypnoides. Therefore, the distribution of S. hypnoides may be restricted to the Indian Ocean, whereas S. aculeata is widely distributed in the Atlantic Ocean including the Mediterranean Sea and the Red Sea. Another Spyridia species with uncinate spines, S. alternans, is recognized as a synonym of S. horridula by our detailed morphological observations of its type specimen.

Biodiversity and phylogenetic analyses using DNA barcoding rbcL gene of seagrass from Sekotong, West Lombok, Indonesia

Abstract. Stevanus, Pharmawati M. 2021. Biodiversity and phylogenetic analyses using DNA barcoding rbcL gene of seagrass from Sekotong, West Lombok, Indonesia. Biodiversitas 22: 50-57. West Lombok, Indonesia is one of the locations that is thought to have a quite high diversity of seagrass. Information on the diversity of seagrass species is important due to the important value of seagrass in the marine ecosystem. This research aimed to analyze biodiversity and phylogenetic of seagrass from Sekotong, West Lombok, Indonesia using DNA barcoding of rbcL gene. As many as 35 samples from seven morphologically identified species (Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Syringodium isoetifolium, Halodule pinifolia, Halophila ovalis, and H. minor) were taken from four Gilis (small island) in Sekotong. The DNA was amplified for the rbcL gene and sequence analyses using BLAST were conducted to determine the species. Phylogenetic analyses were carried out using three evolutionary algorithms using Neighbor-Joining, Maximum Likelihood and Bayesian analysis with 1000 bootstrap. The rbcL gene was successfully amplified from all samples with a maximum length of 552 bp. The phylogenetic analysis showed that clades were split by family and genera where six clades were formed (Enhalus acoroides, T. hemprichii, Halophila complex, H. pinifolia, S. isoetifolium, and C. rotundata) with more than 95% of bootstrap values for Neighbor-Joining and Bayesian. The p-distance values between species were 0.008-0.097 and the polymorphic site was not found within species. The rbcL sequences only confirmed five seagrass species out of seven morphologically identified species and the sequences generated from this study cannot discriminate Halophila ovalis and H. minor.