Volume 57, Issue 5

The occurrence of Stenogramma interruptum in northeast Asian waters is a matter of debate. We analyzed rbc L from Korean specimens filed under the species name S. interruptum in combination with morphological observations. A partial rbc L sequence revealed that the Korean specimens were clearly distinct from other species of Stenogramma as well as S. interruptum from Europe. The morphology and anatomy of the Korean specimens were consistent with the rbc L data. Based on these results, we herein describe the new species Stenogramma guleopensis from Korea. Stenogramma guleopensis is distinguished mostly by its small size (up to 8 cm), slender thallus with narrow and parallel-sided segments, terminal branches basally constricted, two layers of cortical cells, two to three layers of medullary cells, and a gradient of two layers of smaller cells between the cortex and medulla. Further collections and careful examinations in the field will probably reveal extension of the distribution of S. guleopensis to the waters surrounding Korea.

The genus Neoralfsia was newly described by P.-E. Lim and Kawai on the basis of rbc L sequence data from specimens from Japan and Malaysia identified as Neoralfsia expansa , and N. expansa [ Myrionema (?) expansum ] from Mexico was designated as the type species. Our maximum likelihood and Bayesian analyses show that specimens of N. expansa from the type locality are grouped into a new, not previously described, clade in Neoralfsiaceae, distant from that of the putative specimens attributed to N . expansa from Japan and Malaysia. We show that genuine “ expansa ” does not include Asian material. The distribution of the species is not as wide as has been previously recorded.

The brown alga Dictyota canariensis (Grunow) Tronholm has so far been reported only from the eastern Atlantic Ocean (Canary Islands, Cape Verde, Madeira). In the present work, we record the species for the first time from the shores of the Gulf of Mexico, occurring in Montepío, Veracruz. The specimens were collected in December 2011 and October 2013, growing in the intertidal zone on moderately exposed rocky shores. To confirm the identification, we conducted phylogenetic analyses, combining the partial sequences of psb A and cox 1 genes of l7 taxa. The low uncorrected “p” distance values obtained between Mexican and Canary Island specimens for each gene (0.3% for psb A and 1.8% for cox 1) are indicative that these specimens most likely belong to the same species. The low genetic divergence is corroborated by morphological observations, which show that the Mexican specimens share the presence of rectangular pigmented patches near the rounded to obtuse apices, margins with triangle-shaped teeth, and a monostromatic medulla with D. canariensis. Additionally, male reproductive structures are described for the first time for this species.

Sargassum species grow on rocks and dead coral, forming dense seaweed beds in their growth seasons. Sargassum beds play a range of ecological roles in coastal waters, but their sustainability is threatened by pollution and reclamation within ASEAN countries with rapid economic growth. Before conservation initiatives can be implemented, it is necessary to establish their present distribution. These beds can be mapped using the noncommercial satellite, ALOS, which can provide multiband images using high spatial resolution optical sensors (sensitive to 10 m -2 plots), AVNIR-2. These images are of sufficient quality for examining coastal ecosystems and, in this study, for mapping the Sargassum beds in the waters off the coast of Sattahip, Chon Buri Province, Thailand. This coastal zone is a natural marine park reserve and protected from human activities such as fishery and reclamation. Biomass data were obtained in January, February, March, and December 2009 from quadrat sampling. The biomass of Sargassum aquifolium (Turner) C.Agardh at a bottom depth of 1 m and 1.5–2 m was determined to be 7.73 and 92.75 g dw m -2 , while that of Sargassum oligocystum Montagne was found to be 44.05 and 87.97 g dw m -2 , respectively. Ground truth data were obtained in February and October 2012 from serial images taken by manta tow. Supervised classification is a procedure for identifying spectrally similar areas on an image by identifying “training” sites of known targets and then extrapolating those spectral signatures to other areas of unknown targets. By applying this methodology, the Sargassum beds off Sattahip can be detected with an accuracy of about 70%. It is estimated that the error is caused by mixel effects of the bottom substrates in individual pixels, each of which covers an area of 10×10 m. Our results indicate that the images captured by ALOS AVNIR-2 are informative and useful for mapping the Sargassum beds in Southeast Asia.

Seven scale-bearing species of prasinophyceans (Chlorophyta) were studied in light and electron microscopy, pigment analysis, and molecular analysis of the small subunit (SSU) rDNA. Unialgal cultures were obtained from samples collected in the Nervión River estuary, Gulf of Biscay, Spanish Atlantic coast. Five of the species belong to the genus Pyramimonas (Prasinophyceae, Pyramimonaceae) and one each to the genera Mamiella (Mamiellophyceae, Mamiellaceae) and Nephroselmis (Nephroselmidophyceae, Nephroselmidaceae). The morphological features of all the strains analyzed agreed closely with the phylogenetic analysis, which in the case of the genus Pyramimonas presented several clusters corresponding to the subgenera Vestigifera ( Pyramimonas orientalis , Pyramimonas moestrupii ), Punctatae ( Pyramimonas robusta ), Pyramimonas ( Pyramimonas propulsa ), and Trichocystis ( Pyramimonas grossii ). Even though the phylogenetic relationship among these subgenera remains unclear, the results suggested that the Punctatae should remain an independent clade at least until more sequences or genes are analyzed. According to their accessory pigment composition, three groups were distinguished after their pigment ratios were calculated: prasinoxanthin-containing ( Mamiella gilva ), loroxanthin ester-containing ( P. grossii and P. moestrupii ), and siphonaxanthin-containing strains ( Nephroselmis pyriformis and remaining Pyramimonas species). A high intraspecific variability was found, which highlights the need of an in-depth analysis and multiple technique approach to ensure accurate identification of nanoplanktonic microalgae.

In this study, the transcriptome of the marine microalga, Chlorella pyrenoidosa 820, was sequenced by high-throughput RNA-seq using Illumina HiSeq 2000. Because the genome sequence of this species is unknown, the resulting transcriptome was assembled de novo and annotated. This resulted in 4.71G clean nucleotides with a 56.91% GC content and yielded a total of 36,826 unigenes with a mean length of 1089 nt. Among these, 23,015 unigenes were annotated in the NCBI-NR, NCBI-NT, Swiss-Prot, KEGG, COG, and GO databases with a cutoff E-value of 10 -5 . In the annotated sequences, 21 unigenes were identified as carbonic anhydrase (CA), which is an important enzyme in the CO 2 -concentrating mechanism (CCM), and were homologous to nine α-, eight β-, and four γ-CAs. Interestingly, the expression of three CA subtypes, including one α-, one β-, and one γ-CA, analyzed by real-time quantitative PCR, showed induction by high salinity. These results will enrich the CA gene information in the database and will help understand CCM in the genus Chlorella .

Pedumispora rhizophorae , a marine ascomycete reported only from mangrove habitats, was referred to the Diaporthales on the basis of morphological characteristics. To clarify the phylogenetic classification of P. rhizophorae , we re-examined the morphological features of a recent collection of this fungus and evaluated its taxonomic position at the molecular level. Phylogenetic analyses revealed that P. rhizophorae is distantly placed from the Diaporthales, and groups in the Diatrypaceae, Xylariales with strong support. Pedumispora rhizophorae shares many features with members of the Diatrypaceae, including its saprobic habit on decaying plant material, ascomata embedded in a pseudostroma, the presence of paraphyses and pigmented ascospores. However, P. rhizophorae differs from other members of the Diatrypaceae in that this species has apically truncate asci without an apical apparatus, which deliquesce at maturity, whereas diatrypaceous species have persistent long-stalked asci with a more or less truncate apex. Within the Diatrypaceae, the ascospores of most species are allantoid in shape and unicellular, whereas P. rhizophorae possesses septate, filiform ascospores with apical cells lacking cytoplasm. Filiform ascospores and deliquescing asci are common in many unitunicate marine ascomycetes and are regarded as an adaptation to aquatic environment.