An imaging system using a digital single-lens reflex camera with a macro lens and LED illuminator mounted on a glass folding table was examined for accumulating metadata on zooplankton samples. As a result of resolution tests of the imaging system using a stage micrometer (each division＝10 µm), resolutions at each magnification value, 0.15×, 0.37×, 1.3× and 2.6× were estimated as 89, 35, 10 and 5 µm approximately. The dark field images of zooplankton samples were high resolution/high color rendering enough to obtain metadata. The bright field images could be utilized for observations of pigments and oil sacs of copepods. We concluded that the imaging system is economical, easy to operate and is a useful system for zooplankton monitoring and metadata accumulation.

子ども向けの本「もっと知りたい！感染症」の冊子体一式（PDF版）およびE-BOOK版は下記のURLで閲覧できます。

https://sciencewindow.jst.go.jp/kids/03.html

目次

登場する生き物

第1章　インフルエンザってなあに？

p.04　インフルエンザとかぜは違うの？

p.06　インフルエンザの原因は何だろう？

p.08　原因となるものはどれくらい小さいの？

p.12　コラム　この病気にかかったら学校を休んで！

第２章　〈マンガ〉見えない病原体を探して 〜北里柴三郎が切り開いた科学の道〜

p.26　コラム　だれを知っているかな？ ─感染症の研究者たち─

第3章　微生物ってなあに？ 〜

p.30　微生物って悪者なの？

p.32　微生物はいつからいるの？

p.34　病原微生物ってどんな生き物なの？

p.36　病原微生物はどこにいるの？

p.38　コラム　エボラ出血熱とデング熱

第4章　体の中で何が起きているの？ ～免疫細胞と病原微生物の戦い～

p.40　病原微生物はどうやって病気を作り出すの？

p.42　病原微生物が増えるのを止められないの？

p.44　どうやって細菌やウイルスをやっつけるの？

p.50　アレルギーは免疫が原因なの？

p.52　コラム　インフルエンザの治療薬 ─ウイルスを細胞に封じ込める─

第5章　病原微生物はどうやって体の中に？ ～ノロウイルス・О１５7 の正体～

p.54　おなかが痛くなるのはどうして？

p.56　どんな病原微生物が食中毒を起こすの？

p.58　どうやって人の体に入って来るの？

p.60　どうやって体に入れないようにするの？

p.62　もしおなかの中に入ったらどうなるの？

p.64　コラム　キッチンにも病原微生物がたくさん！

第6章　自分を守ることはみんなを守ること

p.66　感染症にかかるのはだれ？

p.68　どうすれば感染症を防げるの？

p.70　コラム　わたしたちの暮らしを感染症から守る社会の仕組み

p.72　コラム　わたしたちを感染症から守る人々

p.74　自分も大切 みんなも大切

p.76　やってみよう！ 手洗い実験

p.77　正しい手の洗い方

p.78　感染症をもっと知りたい

p.80　あとがき

Harmful algal blooms likely occur in enclosed coastal regions and sometimes cause the toxification and/or mortality of marine organisms such as fish and shellfish. To understand the bloom dynamics of harmful algae, it is important to clarify the effects of light intensity on the algal growth. This paper reviews the techniques of photoirradiation and cultivation for analyses of algal growth and discusses the growth responces (light-responsive growth) of harmful algae to various light intensities. As natural light enters the water column, the red color and infrared range of the light are absorbed near the surface of oceanic waters; thus, blue light accounts for a large proportion of PAR (photosynthesis available radiation) penetrating into water. High-brightness white LED (light-emitting diode) is capable of simulating closely such light spectrum of natural PAR in oceanic water. I, along with co-workers, evaluated the light-responsive growth of the harmful species such as Ostreopsis sp. 1 by using a newly developed photoirradiation-culture system which has white LEDs as light source. Our results showed that these tested harmful algae are able to grow at low light intensities of 10⁰~10¹ µmol photons m^-2 s^-1 and even under a strong light of 10³ µmol photons m^-2 s^-1. The optimal light intensities for algal growth seem to be different among the species. This suggests that harmful algae may have divergent growth strategies in response to light intensity. I think that high-brightness white LEDs and a photoirradiation culture system equipped with them can be powerful tools for the understanding of the bloom dynamics of harmful algae.

The brown macroalga, Sargassum horneri, is now attracting attention not only as a food source but also with regard to coast environmental preservation, coastal ecosystems, CO₂ fixation, and as a marine indicator for environmental impact assessment. The present study was conducted to identify the effects of decreased seawater pH on S. horneri growth at three early developmental stages: embryo, germling, and young plant. After being exposed to acidic seawater of pH 6.0–7.5 for approximately 1–5 days, S. horneri embryos could germinate and grow when cultured in seawater with pH 8.0. At the germling stage, S. horneri growth was significantly inhibited when cultured in seawater with pH 6.0–6.6 compared to its growth in seawater with pH 8.0 (control). Moreover, at the young plant stage, S. horneri growth was significantly inhibited when cultured in seawater with pH 7.0 compared to when cultured in seawater with pH 7.5–8.0. These results demonstrate that the effects of decreased pH differ depending on the early growth stage of S. horneri, and as the growth of S. horneri progresses, the adverse effects of low pH increase. The results of this study can be used as preliminary data to promote S. horneri aquaculture in coastal areas and to assess the environmental impacts on its growth.

Plankton are aquatic organisms unable to swim against the current, and they include diverse taxa of different phylogenetic origins. The taxonomy, phylogeny and ecology of nine plankton groups are reviewed in this paper, in order to comprehensively understand the latest information and current situation of plankton studies. The order-level classification of dinoflagellates was re-arranged, but the classification system is still not well organized at the family-level. The taxonomy of raphidophytes and dictyochophytes was partly confused, however, molecular studies provided clear categorization between these groups. The diatoms could be identified by observing some important morphological characteristics. Yet, these characteristics are sometimes not observable because of inappropriate specimen treatments, and furthermore, the morphological terms are not enough unified, resulting that the species-level identification is complicated and difficult. Recent studies revealed the cryptic diversity and high abundance of some microalgae, such as haptophytes and prasinophytes. The diversity and ecology of planktonic foraminifers have been clarified, but those of radiolarians and phaeodarians are still wrapped in mystery. The classification needs to be re-arranged especially for collodarians, phaeodarians and acantharians. The phylogeny of copepods has been elucidated, and this group was re-classified into 10 orders. Future studies should clarify their evolutionary process and create useful databases for easier identification. The methods to reveal the larva-adult correspondence are established for decapods, and further clarification of the correspondence is expected. The classification system of chaetognaths has been updated, and the intra-species diversity is also being studied. The species diversity of scyphozoans has not been well clarified especially for deep-sea species, and their classification still involves problems such as cryptic species. The dataset including DNA sequences and different types of images (taken in the field and under the microscope, etc.) should be accumulated for comparing the data from different methods (e.g., direct microscopy, optics-based survey and environmental DNA analysis).