著者
Yamamori Luna Kato Makoto
出版者
Public Library of Science (PLoS)
雑誌
PLOS ONE (ISSN:19326203)
巻号頁・発行日
vol.13, no.8, 2018-08-22
被引用文献数
9

巻貝が「巻き」を失う進化の過程を解明 --希少なチビアシヤガイ亜科全4種の調査に成功--. 京都大学プレスリリース. 2018-08-27.Flattening of coiled shells has occurred in several gastropod lineages, while the evolutionary process of shell flattening is little known. The subfamily Fossarininae of the top shell family (Trochidae) is unique, because it includes four genera at various stages of shell flattening. Broderipia and Roya, have zygomorphic shells that has lost coiling, while the sister genera, Fossarina and Synaptocochlea, have respectively turbiniform and auriform shells. Therefore, comparisons of biology, habitats and detailed morphology among these four genera may help us to detect selection pressure driving shell flattening and loss of coiling. Although Broderipia has recently been identified as living symbiotically in the pits of sea urchins, the habitats and biology of the other three Fossarininae species, especially Roya are poorly known. After an extensive search on rocky shores of the Japanese Archipelago, we found live Roya eximia snails on intertidal/subtidal rock surfaces exposed to strong waves. Roya snails crept on the bare rock surface to graze periphyton at low tide, and fled into vacant barnacle shells at high tide. Comparison of the morphology of soft bodies in Fossarininae revealed that the columellar muscle of flattened species has been drastically elongated and arranged in posterior semi-outer edge of the flattened shell as observed in true limpets. The flattering and loss of coiling of the shell in Roya caused acquisition of a zygomorphic flat body, retraction of coiled visceral mass, and expansion of the foot sole. All of these changes improved tolerance against strong waves and the ability to cling to rock surfaces, and thus enabled a lifestyle utilizing both wave-swept rock surfaces and the inside of vacant barnacle shells.
著者
YAMAMORI LUNA KATO MAKOTO
出版者
日本プランクトン学会、日本ベントス学会
雑誌
Plankton and Benthos Research (ISSN:18808247)
巻号頁・発行日
vol.14, no.2, pp.131-134, 2019
被引用文献数
2

<p>The rock-boring sea urchin, <i>Echinostrephus molaris</i>, excavates soft rocks, and the pits are later used by non-boring sea urchins such as <i>Echinometra mathaei</i> and <i>Anthocidaris crassispina</i>. The pits used by these non-boring sea urchins are also characteristically inhabited by a limpet-like algivorous trochid snail, <i>Broderipia iridescens</i> (Gastropoda, Trochidae). To determine how this unique symbiotic association is maintained, we observed reproduction and larval development of the snail, and performed assays to detect what induced settlement in the snail larvae. As candidates of settlement inducers, a habitat biofilm plate, the host and the non-host sea urchins, and conspecific snails were kept in separate glass bowls, and newly hatched <i>B. iridescens</i> veliger larvae were introduced to each bowl. Sixty to 80% of larvae settled in bowls that contained the non-boring host sea urchins and conspecific snails. On the other hand, only approximately 8% of the larvae settled in bowls containing the boring non-host sea urchins. This is the first report demonstrating that larval settlement of an algivore is induced not by the habitat biofilms, but by the symbiotic hosts.</p>
著者
NAGAMASU HIDETOSHI KATO MAKOTO
出版者
日本植物分類学会
雑誌
APG : Acta phytotaxonomica et geobotanica (ISSN:13467565)
巻号頁・発行日
vol.55, no.2, pp.75-78, 2004-08-25

A new species, Nothapodytes amamianus Nagam. & Mak. Kato, is described from Amami-oshima, the Ryukyu Isls., and information on its pollination biology is presented. Nothapodytes amamianus is closely related to N. nimmonianus (J. Graham) Mabb., which is widely distributed from S. India to the Ryukyus (Yaeyama group), but is distinguished from the latter by the base of the leaves truncate or shortly cordate, the larger flowers with petals 7-9mm long, and the short but prominent anther connective. This new species is restricted to a small area on Amami-oshima and should be categorized as critically endangered. A key to the Japanese species of Nothapodytes is provided.
著者
Imada Yume Kato Makoto
出版者
Public Library of Science
雑誌
PLOS ONE (ISSN:19326203)
巻号頁・発行日
vol.11, no.11, 2016-11-03
被引用文献数
6

風変わりな口器は葉潜りに合わせて進化した : 植物食の新しい方法を発見. 京都大学プレスリリース. 2016-11-16.