''Syringodium isoetifolium'', commonly known as noodle seagrass, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of flowering plant in the family

Cymodoceaceae Cymodoceaceae is a family of flowering plants, sometimes known as the "manatee-grass family", which includes only marine species. The 2016 APG IV does recognize Cymodoceaceae and places it in the order Alismatales, in the clade monocots. The fam ...

, growing underwater in marine habitats. It forms

seagrass meadow A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

s in shallow sandy or muddy locations in the

Indian Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asia ...

and

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

Description

''Syringodium isoetifolium'' can grow to a length of in single species stands, but may only reach when growing with other seagrass species. The plant has slender underground

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

s which send up shoots at intervals. The shoots are encased in a sheath at the base and each consists of two or three hollow, tubular leaves with smooth pointed tips. In calm waters, the shoots may be long and branched. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is a cyme, with male and female flowers appearing on separate plants. The fruits are small, hard, beaked nuts. The plant is somewhat fragile; leaves may float when they break off, and so may the seed heads, often floating well away from the original location before the seeds germinate.

Ecology

This seagrass is sensitive to light deprivation and a lowering of

salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

in its environment. In a major flooding event in

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

, half the seagrasses were lost in a shallow study area in

Moreton Bay Moreton Bay is a bay located on the eastern coast of Australia from central Brisbane, Queensland. It is one of Queensland's most important coastal resources. The waters of Moreton Bay are a popular destination for recreational anglers and are ...

, the ''Syringodium isoetifolium'' disappearing almost completely while ''

Zostera muelleri ''Zostera muelleri '' is a southern hemisphere temperate species of seagrass native to the seacoasts of South Australia, Victoria and Tasmania.Paul Friedrich August Ascherson. 1867. Sitzungsberichte der Gesellschaft Naturforschender Freunde zu ...

'' and other seagrass species survived, relatively unaffected. Another Australian study examined the likelihood of ''Syringodium isoetifolium'' becoming invasive if its range changed as a result of climate change. In this experiment, a small patch of ''Syringodium isoetifolium'' was established in a tropical subtidal area, and the area covered by the plant increased in size by 800% in a fifteen-year period, mostly through clonal growth.

Research

Marine fouling causes much economic loss from organisms growing on the hulls of ships, pipelines and other submerged structures. Seagrasses have developed defence mechanisms against such

epibiont An epibiont (from the Ancient Greek meaning "living on top of") is an organism that lives on the surface of another living organism, called the basibiont ("living underneath"). The interaction between the two organisms is called epibiosis. An epi ...

s, and few fouling organisms grow on them. A

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...

ic extract of ''Syringodium isoetifolium'' was assessed as a natural antifouling agent. It was found to inhibit growth of

microalgae Microalgae or microphytes are microscopic algae invisible to the naked eye. They are phytoplankton typically found in freshwater and marine systems, living in both the water column and sediment. They are unicellular species which exist indiv ...

and

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

bacteria, as well as the limpet ''

Patella vulgata ''Patella vulgata'', common name the common limpet or common European limpet is a species of sea snail. It is a typical true limpet; a marine gastropod mollusc in the family Patellidae, with gills.Gofas, S. (2014). Patella vulgata Linnaeus, 1758 ...

'' and the brown mussel ''

Perna perna ''Perna perna'', the brown mussel, is an economically important mussel, a bivalve mollusc belonging to the family Mytilidae. It is harvested as a food source but is also known to harbor toxins and cause damage to marine structures. It is nati ...

'', all of which cause marine fouling. The extract was non-toxic to

brine shrimp ''Artemia'' is a genus of aquatic crustaceans also known as brine shrimp. It is the only genus in the family Artemiidae. The first historical record of the existence of ''Artemia'' dates back to the first half of the 10th century AD from Urmia La ...

s and showed promise as an agent to replace the toxic chemicals that have been used historically. The

secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norm ...

s involved seem to be fatty acids in the range C16 to C24.

References

{{Taxonbar Cymodoceaceae