Marimo
Encyclopedia
, also known as Cladophora ball, Lake ball, or Moss Balls in English
, is a species
of filamentous green algae
(Chlorophyta
) found in a number of lakes in the northern hemisphere. A marimo is a rare growth form of the species where the algae grow into large green balls with a velvety appearance. Colonies of such balls are only known to form in Iceland
, Scotland
, Japan
and Estonia
.
, Austria
. The genus Aegagropila was established by Kützing (1843) with A. linnaei as the type species based on its formation of spherical aggregations, but all the Aegagropila species were transferred to subgenus Aegagropila of genus Cladophora later by the same author (Kützing 1849). Subsequently, A. linnaei has been accommodated in the genus Cladophora in the Cladophorales and has been renamed Cladophora aegagropila (L.) Rabenhorst and Cl. sauteri (Nees ex Kütz.) Kütz. Extensive DNA
research in 2002 returned the name to Aegagropila linnaei. The presence of chitin
in the cell walls makes it distinct from the genus Cladophora.
The plant was named "marimo" by a Japanese
botanist
in 1898 (Meiji
31). Mari is a bouncy play ball. Mo is a generic term for plants that grow in water. The native names in Ainu
are tō-rasampe (lake goblin) and tō-karip (lake roller). They are sometimes sold in aquaria
under the name "Japanese moss
balls" although they are unrelated to moss. In Iceland the lake balls are called kúluskítur by the local fishermen at Mývatn
(kúla = ball. skítur = muck) where the "muck" is any weeds that get entangled in their fishing nets. The scientific name Aegagropila (Αεγαγρόπιλα) is Greek for "goat hair".
of any sort.
, Hokkaidō
in Japan and also in Lake Mývatn
in Iceland rank among the strangest plant communities on Earth. Their existence depends on the adaptation of the species for low light conditions, combined with the dynamic interaction of wind-induced currents, light regime, lake morphology, bottom substrate and sedimentation.
The growth rate of Marimo is about 5 mm per year. In Lake Akan
they grow particularly large, up to 20–30 cm (8–12 inches). Mývatn
, Iceland, has dense colonies of marimo that grow to about 12 cm in diameter and form well defined patches on the lake floor at depths ranging from 2–2.5 m. The colonies were discovered in 1978 but have shrunk considerably in size since then. The round shape of the marimo is maintained by gentle wave action that occasionally turns it. The balls are green all the way round which guarantees that they can photosynthesize
no matter which side is turned upwards. Inside, the ball is also green and packed with dormant chloroplast
s which become active in a matter of hours if the ball breaks apart. The wave action also cleans the balls of detritus
. As some colonies have two or even three layers of marimo balls, wave action is needed to tumble them around so each ball reaches the light. The spherical shape has a low surface-area-to-volume ratio and is therefore not optimal for a plant. This limits the maximum size of the marimo balls.
The rapidly declining population of lake balls in Mývatn
is of special concern, but for unknown reason some of the main patches have all but vanished in recent years. At Lake Akan a great effort is spent on the conservation of the lake balls. This includes an annual three day marimo festival in which the Ainu people
, the indigenous people of Hokkaidō
, play an important part. Because of their appealing appearance the lake balls also serve as a medium for environmental education. They bear a certain likeness to the Earth in being green and round and in their need to rotate in order to receive light on all sides. In Japan the marimo has been a protected species
since as early as 1920, defined as a natural treasure. Small balls sold as souvenir
s are hand rolled from free-floating filaments. The marimo was given a status of protected species in Iceland in 2006. It is said that taking good care of the plant will make one's wishes come true. Both Lake Mývatn and Lake Akan are protected, the former as a nature reserve, the latter as a national park
.
Awareness of the unique nature of the marimo has not gone unnoticed in the rest of Japanese culture. A widely marketed stuffed toy character known as Marimokkori
takes the anthropomorphic form of the marimo algae as one part of its design.
English language
English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...
, is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of filamentous green algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
(Chlorophyta
Chlorophyta
Chlorophyta is a division of green algae, informally called chlorophytes. The name is used in two very different senses so that care is needed to determine the use by a particular author...
) found in a number of lakes in the northern hemisphere. A marimo is a rare growth form of the species where the algae grow into large green balls with a velvety appearance. Colonies of such balls are only known to form in Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
and Estonia
Estonia
Estonia , officially the Republic of Estonia , is a state in the Baltic region of Northern Europe. It is bordered to the north by the Gulf of Finland, to the west by the Baltic Sea, to the south by Latvia , and to the east by Lake Peipsi and the Russian Federation . Across the Baltic Sea lies...
.
Classification and nomenclature
They were first discovered in the 1820s by Dr. Anton E. Sauter in Lake ZellerZeller See
Lake Zell is a small freshwater lake in the Austrian Alps. It takes its name from the city of Zell am See which is located on a small delta protruding into the lake. The lake is long and wide...
, Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
. The genus Aegagropila was established by Kützing (1843) with A. linnaei as the type species based on its formation of spherical aggregations, but all the Aegagropila species were transferred to subgenus Aegagropila of genus Cladophora later by the same author (Kützing 1849). Subsequently, A. linnaei has been accommodated in the genus Cladophora in the Cladophorales and has been renamed Cladophora aegagropila (L.) Rabenhorst and Cl. sauteri (Nees ex Kütz.) Kütz. Extensive DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
research in 2002 returned the name to Aegagropila linnaei. The presence of chitin
Chitin
Chitin n is a long-chain polymer of a N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world...
in the cell walls makes it distinct from the genus Cladophora.
The plant was named "marimo" by a Japanese
Japanese people
The are an ethnic group originating in the Japanese archipelago and are the predominant ethnic group of Japan. Worldwide, approximately 130 million people are of Japanese descent; of these, approximately 127 million are residents of Japan. People of Japanese ancestry who live in other countries...
botanist
Botany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...
in 1898 (Meiji
Meiji period
The , also known as the Meiji era, is a Japanese era which extended from September 1868 through July 1912. This period represents the first half of the Empire of Japan.- Meiji Restoration and the emperor :...
31). Mari is a bouncy play ball. Mo is a generic term for plants that grow in water. The native names in Ainu
Ainu language
Ainu is one of the Ainu languages, spoken by members of the Ainu ethnic group on the northern Japanese island of Hokkaidō....
are tō-rasampe (lake goblin) and tō-karip (lake roller). They are sometimes sold in aquaria
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
under the name "Japanese moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
balls" although they are unrelated to moss. In Iceland the lake balls are called kúluskítur by the local fishermen at Mývatn
Mývatn
Mývatn is a shallow eutrophic lake situated in an area of active volcanism in the north of Iceland, not far from Krafla volcano. The lake and its surrounding wetlands have an exceptionally rich fauna of waterbirds, especially ducks...
(kúla = ball. skítur = muck) where the "muck" is any weeds that get entangled in their fishing nets. The scientific name Aegagropila (Αεγαγρόπιλα) is Greek for "goat hair".
Growth forms
There are three growth forms. One is epilithic (growing on rocks) and is usually found on the shaded side of the rocks. Another growth form lives as free-floating filaments, as small tufts of unattached filaments that frequently form a carpet on the muddy lake bottom. The third growth form is the lake ball proper, where the algae grow into sizable balls of densely packed algal filaments that radiate from the center. The balls do not have a kernelSeed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
of any sort.
Ecology
Marimo colonies in Lake AkanAkan National Park
is a national park located on the island of Hokkaidō, Japan. Along with Daisetsuzan National Park, these are the two oldest national parks in Hokkaidō. The park was established December 4, 1934....
, Hokkaidō
Hokkaido
, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...
in Japan and also in Lake Mývatn
Mývatn
Mývatn is a shallow eutrophic lake situated in an area of active volcanism in the north of Iceland, not far from Krafla volcano. The lake and its surrounding wetlands have an exceptionally rich fauna of waterbirds, especially ducks...
in Iceland rank among the strangest plant communities on Earth. Their existence depends on the adaptation of the species for low light conditions, combined with the dynamic interaction of wind-induced currents, light regime, lake morphology, bottom substrate and sedimentation.
The growth rate of Marimo is about 5 mm per year. In Lake Akan
Akan National Park
is a national park located on the island of Hokkaidō, Japan. Along with Daisetsuzan National Park, these are the two oldest national parks in Hokkaidō. The park was established December 4, 1934....
they grow particularly large, up to 20–30 cm (8–12 inches). Mývatn
Mývatn
Mývatn is a shallow eutrophic lake situated in an area of active volcanism in the north of Iceland, not far from Krafla volcano. The lake and its surrounding wetlands have an exceptionally rich fauna of waterbirds, especially ducks...
, Iceland, has dense colonies of marimo that grow to about 12 cm in diameter and form well defined patches on the lake floor at depths ranging from 2–2.5 m. The colonies were discovered in 1978 but have shrunk considerably in size since then. The round shape of the marimo is maintained by gentle wave action that occasionally turns it. The balls are green all the way round which guarantees that they can photosynthesize
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
no matter which side is turned upwards. Inside, the ball is also green and packed with dormant chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
s which become active in a matter of hours if the ball breaks apart. The wave action also cleans the balls of detritus
Detritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
. As some colonies have two or even three layers of marimo balls, wave action is needed to tumble them around so each ball reaches the light. The spherical shape has a low surface-area-to-volume ratio and is therefore not optimal for a plant. This limits the maximum size of the marimo balls.
Conservation and cultural aspects
Mývatn
Mývatn is a shallow eutrophic lake situated in an area of active volcanism in the north of Iceland, not far from Krafla volcano. The lake and its surrounding wetlands have an exceptionally rich fauna of waterbirds, especially ducks...
is of special concern, but for unknown reason some of the main patches have all but vanished in recent years. At Lake Akan a great effort is spent on the conservation of the lake balls. This includes an annual three day marimo festival in which the Ainu people
Ainu people
The , also called Aynu, Aino , and in historical texts Ezo , are indigenous people or groups in Japan and Russia. Historically they spoke the Ainu language and related varieties and lived in Hokkaidō, the Kuril Islands, and much of Sakhalin...
, the indigenous people of Hokkaidō
Hokkaido
, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...
, play an important part. Because of their appealing appearance the lake balls also serve as a medium for environmental education. They bear a certain likeness to the Earth in being green and round and in their need to rotate in order to receive light on all sides. In Japan the marimo has been a protected species
Conservation status
The conservation status of a group of organisms indicates whether the group is still extant and how likely the group is to become extinct in the near future...
since as early as 1920, defined as a natural treasure. Small balls sold as souvenir
Souvenir
A souvenir , memento, keepsake or token of remembrance is an object a person acquires for the memories the owner associates with it. The term souvenir brings to mind the mass-produced kitsch that is the main commodity of souvenir and gift shops in many tourist traps around the world...
s are hand rolled from free-floating filaments. The marimo was given a status of protected species in Iceland in 2006. It is said that taking good care of the plant will make one's wishes come true. Both Lake Mývatn and Lake Akan are protected, the former as a nature reserve, the latter as a national park
National park
A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or...
.
Awareness of the unique nature of the marimo has not gone unnoticed in the rest of Japanese culture. A widely marketed stuffed toy character known as Marimokkori
Marimokkori
is a character popularized in Hokkaidō, Japan. Much like the Tamagochi, the name "Marimokkori" is a pun: marimo is the word for the green algae clusters that grow in some of Hokkaidō's lakes, while mokkori is a Japanese slang term for an erection....
takes the anthropomorphic form of the marimo algae as one part of its design.
Care for domestic marimo
Domestic marimo grow in tap water at room temperature as long as the water is changed every one or two weeks (more frequently in summer and less often in winter). The marimo can be placed in the refrigerator in hot weather (above 25°C), but does not survive freezing. Photosynthesis occurs in normal household lighting, otherwise, indirect sunlight since the marimo is adapted for low light conditions only. If the marimo green color turns brownish it may recover without intervention, otherwise a very minimal amount of salt can be added as a suggested remedy.See also
External links
- Japan Atlas
- Marimo Balls - Marimo ball information (scroll below ad)
- Cladophora aegagropila, Marimo
- Aegagropila linnaeii on The Aquarium Wiki Encyclopaedia