Biodiversity of coralline algae: taxonomy and ecology of ‘living stone’

紅藻サンゴモ類は，体を石灰質で石のように硬くする「石灰藻」の代表的な存在である。熱帯～亜熱帯域ではサンゴ礁形成に貢献する一方，温帯～寒帯では，海の森となる藻場が衰退・消失した磯焼け域に繁茂する海藻として知られている。本稿では，サンゴ礁や藻場におけるサンゴモ類の生物学的特徴について概説する。サンゴ礁科学研究-IV : 喜界島サンゴ礁科学研究所設立記念

Nanostructure-enhanced infrared spectroscopy

While infrared spectroscopy is a powerful technique that provides molecular information such as chemical constituents and chemical structures of analytes, it suffers from low absorption cross-section resulting in low sensitivity and poor signal-to-noise or signal-to-background ratios. Surface-enhanced infrared absorption (SEIRA) spectroscopy, which is supported by nanometer scale structures, is a promising technology to overcome these problems in conventional infrared (IR) spectroscopy and enhances IR signals using the field enhancement properties of surface plasmon resonance. Recently resonant SEIRA technique was proposed, and signal enhancement factor was significantly improved. In this review, we present an overview of the recent progresses on resonant SEIRA technologies including nanoantenna- and metamaterial-based SEIRA, and also SEIRA techniques with nanoimaging capabilities

Taxonomic and Distributional Accounts on the Non-geniculate Coralline Algae in Japan

日本産無節サンゴモ（サンゴモ目，ハパリデウム目，エンジイシモ目）の分類と分布について，博物館所蔵標本および新たに採集された標本を形態・解剖学的に観察し，再検討した。その結果，日本から既報告の98分類群のうち，75分類群（72種3品種）が日本産として確認された。残り23分類群は12分類群が日本産から除外，7分類群が他種の異名，4分類群が不明な種として扱われた。日本新産種として9種（エンリンモカサ，カンムリモカサ，ジュウジモカサ，クサビイシゴロモ，カスミイシゴロモ，チヂミオコシ，ナンカイオコシ，フナフチオコシ，オオエンジイシモ）が加わった。日本がタイプ産地である32分類群（26種6品種）は，ほとんどのタイプ標本の再調査が未実施である。日本産の各種について，命名法，異名表，詳細な形態の記載と図解，標本に基づく分布を記載した。Taxonomic and distributional accounts of non-geniculate coralline algae (Corallinales, Hapalidiales, Sporolithales) previously reported from Japan were re-evaluated based on the herbarium and newly collected specimens by morphological and anatomical observations. Of the 98 taxa previously reported in Japan, 75 taxa (72 species and 3 forms) were confirmed to occur. The remaining 23 taxa were treated as species excluded from Japanese flora (12 taxa), synonyms of other taxa (7 taxa) or species of uncertain status (4 taxa), respectively. Nine species were newly recorded for Japan (Heteroderma gibbsii , Pneophyllum coronatum , Hydrolithon cruciatum, Lithophyllum cuneatum , Lithophyllum insipidum , Lithothamnion crispatum , Lithothamnion proliferum, Mesophyllum funafutiense and Sporolithon episoredion). Most of the types of 32 taxa (26 species and 6 forms) reported from Japan have not been re-examined in modern methods. For each Japanese species, nomenclature, synonymy, detailed morphological and anatomical accounts, and distribution based on examined specimens are presented

Floristic and phenological study of marine macroalgae in the vicinity of Takehara, Hiroshima Prefecture on the western central coasts of the Seto Inland Sea of Japan

The species composition and seasonal occurrence of the marine macroalgae on the central coast of Hiroshima Prefecture, specifically in the vicinity of Takehara, in the Seto Inland Sea of Japan were studied. A total of 143 species was identified including 18 species of Chlorophyceae, 43 species of Phaeophyceae, and 82 species of Rhodophyceae. Most species were seasonal and more abundant from February to July, when more than 60 species occurred in each month. March had 79 species, the highest species number in a single month. Ulva pertusa, Codium fragile, Ishige okamurae, Ecklonia kurome, Sargassum fusiforme, S. thunbergii, Corallina pilulifera, and Chondrus giganteus were found throughout the year. Of 143 species, Dictyota linearis, Sporochnus radiciformis, and Martensia fragilis were warm temperate species that reported in the Bungo-channel regions, while only Dictyota linearis can be found in the southern islands of subtropical Japan. The rest of the species were temperate species. There are 104 species commonly found on the coasts of Hiroshima Prefecture, representing the major algal communities along the coast of the Prefecture

Ultrastable tip-enhanced hyperspectral optical nanoimaging for defect analysis of large-sized WS2 layers

Optical nanoimaging techniques, such as tip-enhanced Raman spectroscopy (TERS), are nowadays indispensable for chemical and optical characterization in the entire field of nanotechnology and have been extensively used for various applications, such as visualization of nanoscale defects in two-dimensional (2D) materials. However, it is still challenging to investigate micrometer-sized sample with nanoscale spatial resolution because of severe limitation of measurement time due to drift of the experimental system. Here, we achieved long-duration TERS imaging of a micrometer-sized WS2 sample for 6 hours in a reproducible manner. Our ultrastable TERS system enabled to reveal the defect density on the surface of tungsten disulfide layers in large area equivalent to the device scale. It also helped us to detect rare defect-related optical signals from the sample. The present study paves ways to evaluate nanoscale defects of 2D materials in large area and to unveil remarkable optical and chemical properties of large-sized nanostructured materials

Highly Stable Polymer Coating on Silver Nanoparticles for Efficient Plasmonic Enhancement of Fluorescence

Surface coating of plasmonic nanoparticles is of huge importance to suppress fluorescence quenching in plasmon-enhanced fluorescence sensing. Herein, a one-pot method for synthesizing polymer-coated silver nanoparticles was developed using a functional polymer conjugated with disulfide-containing anchoring groups. The disulfides played a crucial role in covalently bonding polymers to the surface of the silver nanoparticles. The covalent bond enabled the polymer layer to form a long-term stable coating on the silver nanoparticles. The polymer layer coated was adequately thin to efficiently achieve plasmonic enhancement of fluorescence and also thick enough to effectively suppress quenching of fluorescence, achieving a huge net enhancement of fluorescence. The polymer-coated plasmonic nanoparticles are a promising platform for demonstrating highly sensitive biosensing for medical diagnostics

Ecological characteristics of Ecklonia cava ssp. kurome (Laminariales, Phaeophyceae) in the western Seto Inland Sea I. biomass, production rates and morphological diversity

クロメは瀬戸内海中央・西部海域に唯一分布するアラメ・カジメ類であり，藻場の構成種として極めて重要である。本報では2012～13年に瀬戸内海西部（平郡島，片島，屋代島）で調査したクロメの現存量，生産量などの諸元を取りまとめた。優占群落における繁茂期（6～7月）の平均現存量は0.7～1.3kg乾重 m-2であり，成体の平均密度はおおむね10～20個体m-2であった。片島と屋代島・松ヶ鼻において，葉状部のマーキング法で測定した生産量は，繁茂期に10.4～15.6g乾重m-2日-1，衰退期（10～11月）に1.8～5.3g乾重m-2日-1，成長期（2～3月）に5.8～12.9g乾重m-2日-1 であり，本海域のクロメは太平洋や東シナ海のクロメおよび近縁のカジメと同程度の生産力を有していた。繁茂期の成体の茎長や中央葉の長さと幅の比，PPNI値等には調査地間で有意な差異があり，クロメの形態にはそれぞれの生育環境を反映すると推測される多様性がみとめられた。Ecklonia cava ssp. kurome is the only perennial kelp which is distributed in the central and western areas of the Seto Inland Sea, and is an important component of macroalgal beds in these areas. Biomass and production rates of this species were surveyed at three islands (Heigun-jima Is., Kata-shima Is. and Yashiro-jima Is.) in the western Seto Inland Sea during 2012–13. The mean biomass of dominant stands in the luxuriant season (June–July) ranged from 0.7 to 1.3 kg DW m-2 and the mean adult thallus density was approximately in the range of 10–20 inds. m-2. Net production was estimated by the leaf-marking method at Kata-shima Is. and Matsu-ga-hana in Yashiro-jima Is. Estimated production rates were 10.4–15.6 g DW m-2 d-1 in the luxuriant season, 1.8–5.3 g DW m-2 d-1 in the senescent season (October–November), and 5.8–12.9 g DW m-2 d-1 in the growth season (February–March). These trends were similar to those for E. cava ssp. kurome and its closely related E. cava ssp. cava reported in the Pacific Ocean and East China Sea, respectively. Morphological characteristics, such as stipe length, length/width ratio of the central blade and the primary pinna number index (PPNI) of adult E. cava ssp. kurome thalli exhibited significant differences in the luxuriant season among the survey sites, which reflected variable environmental conditions in their habitats.本研究は，水産庁「地球温暖化対策推進費委託事業」のうち「藻場・干潟の炭素吸収源評価と吸収機能向上技術の開発」（平成23，24年度）の一環として実施し， とりまとめにあたってはJSPS科研費18H02268（代表者；吉田吾郎）の助成を受けた

Morphological and molecular assessment of Lithophyllum okamurae with the description of L. neo-okamurae sp. nov. (Corallinales, Rhodophyta)

Lithophyllum okamurae has been widely reported in the Pacific Ocean with identification based on morpho-anatomical observations. Two infraspecific taxa, L. okamurae f. okamurae and f. angulare, described from Japan, have been recorded in the temperate region of Japan. We assessed branched Lithophyllum samples morphologically referable to L. okamurae using morpho-anatomical data and DNA sequences (psbA, rbcL and partial LSU rDNA) obtained from herbarium specimens, including type material, as well as recently field-collected material in Japan. The molecular analyses showed that these ‘L. okamurae’ samples contained two species: L. okamurae and a cryptic new species which we describe as L. neo-okamurae sp. nov. Because the holotype of L. okamurae f. angulare was conspecific with original material cited in the protologue of L. okamurae, it is a heterotypic synonym of L. okamurae f. okamurae. Lithophyllum okamurae and L. neo-okamurae were morphologically similar in having warty, lumpy and fruticose thalli and in often forming rhodoliths. Lithophyllum okamurae can be morpho-anatomically distinguished from L. neo-okamurae by the thallus with tapering or plate-like protuberances (knobby protuberances in the latter) and by having smaller tetrasporangial conceptacle chambers (167–314 μm; 248–380 μm in L. neo-okamurae). Our LSU rDNA sequence data from L. okamurae f. angulare (=L. okamurae f. okamurae) was identical to that of the type of L. margaritae, which has nomenclatural priority over L. okamurae. However, considering that psbA and rbcL sequences of L. margaritae type material could not be generated in the present study, we refrain, for the moment, from proposing the taxonomic synonymy between these two taxa until the status of L. margaritae and its synonyms from the type locality (Gulf of California) are clarified.This research was mainly supported by Japan Society for the Promotion of Science (JSPS KAKENHI Grant Number 26850123, 17K07908) to AK

CPL on/off control of an assembled system by water soluble macrocyclic chiral sources with planar chirality

Herein, we report the synthesis and planar chiral properties of a pair of water-soluble cationic pillar[5]arenes with stereogenic carbons. Interestingly, although units of the molecules were rotatable, only one planar chiral diastereomer existed in water in both cases. As a new type of chiral source, these molecules transmitted chiral information from the planar chiral cavities to the assembly of a water-soluble extended π-conjugated compound, affording circularly polarized luminescence (CPL). The chirality transfer process and resulting CPL were extremely sensitive to the feed ratio of the chiral pillar[5]arenes owing to the combined action of their planar chirality, bulkiness, and strong binding properties. When a limited amount of chiral source was added, further assembly of the extended π-conjugated compound into helical fibers with CPL was triggered. Unexpectedly, larger amounts of chiral source destroyed the helical fiber assemblies, resulting in elimination of the chirality and CPL properties from the assembled structures