Evidence map›Paper›PMID 34759312›Full record

ArticleScientific reports2021

The structure and formation of giant Marimo (Aegagropila linnaei) in Lake Akan, Japan.

Keisuke Nakayama, Katsuaki Komai, Keisuke Ogata, Toshiro Yamada, Yukinobu Sato, Fumiya Sano, Shintarou Horii, Yuichiro Somiya, Etsuko Kumamoto, Yoichi Oyama

Open access · goldAbstract read
In one paragraph

Article in Scientific reports, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.8field-weighted citation impact, top 25% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 7 citations in OpenAlex.

  1. Marimo for monitoring and filtering of aquatic environments.Environmental science and pollution research international · 2025
    Article
  2. Article
  3. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors at 4 institutions in 1 country.

Keisuke NakayamaGraduate School of Engineering, Kobe University, Kobe, 657-8501, Japan. nakayama@phoenix.kobe-u.ac.jp.
Katsuaki Komai *Faculty of Engineering, Kitami Institute of Technology, Kitami, 090-8507, Japan.
Keisuke OgataGraduate School of Engineering, Kobe University, Kobe, 657-8501, Japan.
Toshiro YamadaNishimuragumi Co., Ltd., Yubetsu, 099-6404, Japan.
Yukinobu SatoHousui Engineering Consultants Co., LTD., Sapporo, 065-0033, Japan.
Fumiya SanoHousui Engineering Consultants Co., LTD., Sapporo, 065-0033, Japan.
Shintarou HoriiCenter of Radiology and Radiation Oncology, Kobe University Hospital, Kobe, Japan.
Yuichiro SomiyaCenter of Radiology and Radiation Oncology, Kobe University Hospital, Kobe, Japan.
Etsuko KumamotoGraduate School of Engineering, Kobe University, Kobe, 657-8501, Japan.
Yoichi Oyama *Marimo Research Center, Kushiro Board of Education, Kushiro, 085-0467, Japan.
Kobe University · JPKobe University Hospital · JPKitami Institute of Technology · JPNomura Holdings (Japan) · JP

Funding

Japan Society for the Promotion of Science 18H01545
6 · The paper itself

Abstract

Aegagropila linnaei is a freshwater green alga, which at one time was distributed widely in the northern hemisphere. The aggregate often forms beautiful spherical shapes known as "lake balls" or "Marimo". The population of Marimo has been rapidly decreasing worldwide, and today the large Marimo, with a diameter of more than 12 cm, exit only in Lake Akan in Japan. However, how Marimo grow and maintain their unique spherical shape in natural habitats remains unsolved. Here we show that Marimo are "polished" into spheres by the rotation induced by wind waves. Such a process enhances the water exchange between the interior and exterior of the Marimo, thereby recycling nutrients for growth. Our results provide an intriguing model of a physical environment interacting with biological processes in a self-sustaining ecosystem. We also demonstrate that Marimo have a spherical annual ring structure, and their growth rate is associated with ice cover. The balance between the ecology of Marimo and the water environment in Lake Akan is highly vulnerable and at risk of irreversible degradation. We must endeavor to rescue Marimo from the fate of a "canary in the coal mine" of global climate change.

Identifiers

PMID34759312
PMCPMC8581023
OpenAlexW3212053310

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.