''Azolla pinnata'' is a species of
fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...
known by several common names, including mosquitofern, feathered mosquitofern and water velvet. It is native to much of Africa, Asia (
Brunei Darussalam
Brunei ( , ), formally Brunei Darussalam ( ms, Negara Brunei Darussalam, Jawi: , ), is a country located on the north coast of the island of Borneo in Southeast Asia. Apart from its South China Sea coast, it is completely surrounded by the ...
,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
,
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
,
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
,
Korea
Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...
, and the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
) and parts of Australia. It is an
aquatic plant
Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that ...
, it is found floating upon the surface of the water. It grows in quiet and slow-moving water bodies because swift currents and waves break up the plant.
[Pacific Island Ecosystems at Risk]
/ref> At maximum growth rate, it can double its biomass in 1.9 days, with most strains attaining such growth within a week under optimal conditions.[ The hairs make the top surface of the leaf water-repellent, keeping the plant afloat even after being pushed under.][ A water body may be coated in a dense layer of the plants, which form a velvety mat that crowds out other plants.][ The hairlike roots extend out into the water.][ The leaves contain the ]cyanobacterium
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue ...
'' Anabaena azollae'', which is a symbiont
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
that fixes nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
from the atmosphere that the fern can use.[Sood, A., et al. (2005). Indicators of phosphorus deficiency in ''Azolla pinnata'' (Salviniales, Pteridophyta). ''Acta Botanica Hungarica'' 47:1-2 197.] This gives the fern the ability to grow in habitats that are low in nitrogen.[
The plant reproduces vegetatively when branches break off the main axis, or sexually when sporocarps on the leaves release spores.][''Azolla pinnata''.]
Nonindigenous Aquatic Species. USGS
It is present in New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
as an introduced species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...
and an invasive weed
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
that has crowded out a native relative, ''Azolla rubra
''Azolla rubra,'' known commonly as red azolla and Pacific azolla is a species of fern native to Australia and New Zealand. In New Zealand, it may also be known by its Māori names , , and .
Distribution
''Azolla rubra'' is found in Australia ...
''.[ It is a pest of waterways because its dense mats reduce oxygen in the water.][''Azolla pinnata''.]
Idaho Agriculture. The weevil
Weevils are beetles belonging to the Taxonomic rank, superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and Herbivore, herbivorous. Approximately 97,000 species of weevils are known. They b ...
'' Stenopelmus rufinasus'' is used as an agent of biological pest control
Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ...
to manage ''Azolla filiculoides
''Azolla filiculoides'' (water fern) is a species of ''Azolla'', native to warm temperate and tropical regions of the Americas which was introduced to Europe, North and sub-Saharan Africa, China, Japan, New Zealand, Australia, the Caribbean and H ...
'', and it has been found to attack ''A. pinnata'' as well.[Pemberton, R. W. and J. M. Bodle. (2009)]
Native North American Azolla Weevil, ''Stenopelmus rufinasus'' (Coleoptera: Curculionidae), uses the invasive old world ''Azolla pinnata'' as a host plant.
''Florida Entomologist'' 92:1 153.
Rice farmers sometimes keep this plant in their paddies because it generates valuable nitrogen via its symbiotic cyanobacteria.[ The plant can be grown in wet soil and then plowed under, generating a good amount of nitrogen-rich ]fertilizer
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
.[Kaur, H]
Biomass production of ''Azolla pinnata'' R. Br. in contaminated soils of Punjab (India).
/ref> The plant has the ability to absorb a certain amount of heavy metal pollution, such as lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
, from contaminated water.[Jain, S. K. (1990).''Azolla pinnata'' R.Br. and ''Lemna minor'' L. for removal of lead and zinc from polluted water. ''Water Research 24:2 177-83.] It is 25-30% protein and can be added to chicken feed
Poultry feed is food for farm poultry, including chickens, ducks, geese and other domestic birds.
Before the twentieth century, poultry were mostly kept on general farms, and foraged for much of their feed, eating insects, grain spilled by cattl ...
.[Basak, B., et al. (2002)]
Azolla (''Azolla pinnata'') as a feed ingredient in broiler ration.
''International Journal of Poultry Science'' 1:1 29.[Alalade, O. A. and E. A. Iyayi. (2006)]
Chemical composition and the feeding value of azolla (''Azolla pinnata'') meal for egg-type chicks.
''International Journal of Poultry Science'' 5:2 137.
Applications in environmental studies
Recent studies show the usefulness of ''Azolla pinnata'' in the remediation of environmental pollutants. There are two main methods for utilising ''A. pinnata'' to clean up environmental pollutants. The first method is by adsorption
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which a f ...
, which required the ''A. pinnata'' fronds to be processed into powder and agitated with the wastewater for a fixed duration. The pollutant will adhere to the organic functional groups on the surface of the ''A. pinnata'' powder. In adsorption studies, ''A. pinnata'' was reported in the remediation of dye wastewater containing methyl violet 2B, malachite green
Malachite green is an organic compound that is used as a dyestuff and controversially as an antimicrobial in aquaculture. Malachite green is traditionally used as a dye for materials such as silk, leather, and paper. Despite its name the dye is ...
, rhodamine B
Rhodamine B is a chemical compound and a dye. It is often used as a tracer dye within water to determine the rate and direction of flow and transport. Rhodamine dyes fluoresce and can thus be detected easily and inexpensively with fluorometers.
...
, acid red 88 and acid blue 25.
The second remediation method is phytoremediation, where living ''A. pinnata'' is suspended on the surface of the wastewater. ''A. pinnata'' was primarily studied due to its high tolerance to environmental pollutants, and ability to hyperaccumulate heavy metals.Phytoremediation
Phytoremediation technologies use living plants to clean up soil, air and water contaminated with hazardous contaminants. It is defined as "the use of green plants and the associated microorganisms, along with proper soil amendments and agronom ...
of industrial wastewater containing heavy metals (such as zinc, lead, chromium, mercury, cadmium, copper, arsenic
References
External links
USDA Plants Profile - ''Azolla pinnata''
*
{{Taxonbar, from=Q2875199
Salviniales
Freshwater plants
Ferns of Asia
Ferns of Africa
Ferns of Australia
Nitrogen-fixing crops