Enhalus

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Enhalus
Enhalus acoroides01.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Alismatales
Family: Hydrocharitaceae
Genus: Enhalus
Rich. [2]
Species:
E. acoroides
Binomial name
Enhalus acoroides
Synonyms [4]
  • Stratiotes acoroidesL.f.
  • Enhalus koenigiiRich.
  • Vallisneria sphaerocarpaBlanco
  • Enhalus marinusGriff.

Enhalus is a monotypic genus of marine flowering plants. [5] The sole species is Enhalus acoroides. Enhalus is a large seagrass native to coastal waters of the tropical Indian and Western Pacific Oceans. [5] It is the only species of seagrass that does aerial surface pollination in which the pollen and the styles remain dry. [6] Enhalus is surface pollinated with male flowers that detach from the plant to float on the surface until they reach a female flower where pollination can occur. [5] Enhalus acoroides is considered a slow-growing, "climax" species. [7]

Contents

Description

Enhalus acoroides massive rhizomes (1.5 cm in diameter) help it stay anchored in soft mud substrates, withstanding wave action and tidal currents. it has long strap like leaves (30–150 cm) which make up a significant volume of total plant biomass of shallow water seagrass beds, because of the large structure of the leaves and where they are in the water column, they provide greater surfaces for Epibiont organisms to inhabit. [8] Fruit are round and large (4–6 cm in diameter) with dark, ribbed skin and 6-7 white seeds. The male plant bears a single pedunculate inflorescence or stem containing clusters of flowers, each is highly reduced in form to a small free floating device. Female Enhalus acoroides bears only a single inflorescence, but the peduncle of a female flower is much longer. [8]

Distribution and habitat

Enhalus acoroides is a littoral species living in shallow soft substrates like muddy or sand-flats and coral substrates depending the region of growth. It can be found as far east as Papua New Guinea and can range from the Red Sea south to northern Mozambique in the Indian Ocean. [9] It can be found in mixed meadows of seagrasses comprising 90% of the meadow biomass mainly with Thallassia hemprichii. [10] it can also be found living in isolated areas. Enhalus acoroides grows best just above the level of mean low water springs and grows to generally 4 meters deep. [6]

Reproduction

Enhalus acoroides is dioecious and able to reproduce sexually and asexually. [10] Enhalus acoroides create small isolated patches containing 25 to 200 shoots through lateral rhizome spreading. It can also produce pollen like other seagrasses but it is unique in that it is the only species of seagrasses that surface pollinates. During this process, the male flower will break off from the spathe and rise to the surface where it has numerous flowers inside its hydrophobic inflorescences. [10] Once at the surface it will release its pollen to a female inflorescence where it has reached the surface of the water by means of an elongated stalk surface. The developing fruit is drawn under the water to finish ripening. Flowering is a year round phenomenon and the amount of flowers being produced are strongly related to variations in mean water temperatures. [10]

Related Research Articles

Seagrass plants that grow in marine environments

Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families, all in the order Alismatales. Seagrasses evolved from terrestrial plants which recolonised the ocean 70 to 100 million years ago.

Seagrass meadow Underwater ecosystem

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 long green, grass-like leaves. They produce seeds and pollen and have roots and rhizomes which anchor them in seafloor sand.

Cymodoceaceae Family of aquatic plants

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Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from the parent or parents. Asexual reproduction produces new individuals without the fusion of gametes, clonal plants that are genetically identical to the parent plants and each other, unless mutations occur.

<i>Phyllospadix scouleri</i> Species of aquatic plant

Phyllospadix scouleri, or Scouler's surfgrass, is a flowering marine plant in the family Zosteraceae. It is native to the coastline of western North America from the Alaskan panhandle to Baja California.

<i>Halophila johnsonii</i> Species of aquatic plant

Halophila johnsonii, or Johnson's seagrass, is a small, asexual seagrass in the family Hydrocharitaceae. It occurs only on the southeastern coast of Florida, and was the first marine plant listed on the United States endangered species list, where it is listed as a threatened species. Female flowers have been observed, but even with decade long observational studies, neither male flowers nor seed have ever been observed.

<i>Nymphoides peltata</i> Species of aquatic plant

Nymphoides peltata is perennial, rooted aquatic plant with floating leaves of the family Menyanthaceae.

<i>Posidonia australis</i> Species of plant

Posidonia australis is a species of seagrass that occurs in the southern waters of Australia. It is sometimes referred to as fibreball weed. It forms large meadows important to environmental conservation. Balls of decomposing detritus from the foliage are found along nearby shore-lines.

<i>Phyllospadix</i> Genus of aquatic plants

Phyllospadix, surfgrass, is a genus of seagrass, a flowering plant in the family Zosteraceae, described as a genus in 1840. Phyllospadix grows in marine waters along the coasts of the temperate North Pacific.

<i>Thalassia</i> (plant) Genus of aquatic plants

Thalassia is a marine seagrass genus comprising two known species.

<i>Thalassia testudinum</i> Species of aquatic plant

Thalassia testudinum, commonly known as turtlegrass, is a species of marine seagrass. It forms meadows in shallow sandy or muddy locations in the Caribbean Sea and the Gulf of Mexico. Turtle grass and other seagrasses form meadows which are important habitats and feeding grounds. The grass is eaten by turtles and herbivorous fish, supports many epiphytes, and provides habitat for juvenile fish and many invertebrate taxa.

<i>Zostera marina</i> Species of aquatic plant

Zostera marina is a flowering vascular plant species as one of many kinds of seagrass, with this species known primarily by the English name of eelgrass with seawrack much less used, and refers to the plant after breaking loose from the submerged wetland soil, and drifting free with ocean current and waves to a coast seashore. It is a saline soft-sediment submerged plant native to marine environments on the coastlines of northern latitudes from subtropical to subpolar regions of North America and Eurasia.

<i>Cymodocea nodosa</i> species of plant in the family Cymodoceaceae

Cymodocea nodosa is a species of seagrass in the family Cymodoceaceae and is sometimes known as little Neptune grass. As a seagrass, it is restricted to growing underwater and is found in shallow parts of the Mediterranean Sea and certain adjoining areas of the Atlantic Ocean.

Blue carbon Carbon captured by the worlds marine ecosystems

Blue carbon is carbon sequestration by the world's oceanic and coastal ecosystems, mostly by algae, seagrasses, macroalgae, mangroves, salt marshes and other plants in coastal wetlands. This occurs through plant growth and the accumulation and burial of organic matter in the soil. Because oceans cover 70% of the planet, ocean ecosystem restoration has the greatest blue carbon development potential. Research is ongoing, but in some cases it has been found that these types of ecosystems remove far more carbon than terrestrial forests, and store it for millennia.

<i>Zostera noltei</i> Species of plant

Zostera noltii is a species of seagrass known by the common name dwarf eelgrass. It is found in shallow coastal waters in north western Europe, the Mediterranean Sea, Black Sea, Caspian Sea and Aral Sea and on islands in the Atlantic off the coast of northwest Africa. It is an important part of the intertidal and shallow subtidal ecosystems of estuaries, bays and lagoons.

<i>Halodule uninervis</i> species of plant in the family Cymodoceaceae

Halodule uninervis is a species of seagrass in the family Cymodoceaceae. It is native to the western Pacific and Indian Oceans. Common names include narrowleaf seagrass in English and a'shab bahriya in Arabic.

<i>Thalassodendron ciliatum</i> Species of aquatic plant

Thalassodendron ciliatum, the sickle-leaved cymodocea, is a species of plant in the Thalassodendron genus of seagrasses in the family Cymodoceaceae.

Zostera novazelandica Setchell is a species of seagrass in the family Zosteraceae found on the shores of New Zealand. It is regarded as a distinct species by some authors but considered as a synonym of Zostera muelleri Irmisch ex Ascherson by others. The Maori names for Zostera novazelandica are karepō, nana, rehia, and rimurehia.

Zostera muelleri is a southern hemisphere temperate species of seagrass native to the seacoasts of South Australia, Victoria and Tasmania. and New Zealand. Today, Zostera muelleri can be found in regions of Australia, New Zealand, and Papua New Guinea, as well as areas of the eastern Indian Ocean, and the southwest and western central Pacific Ocean. Zostera muelleri is a marine angiosperm, and is commonly referred to as eelgrass or garweed. It is a fast growing and readily colonizing species that serves as a feeding ground for wading birds and aquatic animals, and a breeding ground for juvenile fish and shrimp species.

<i>Syringodium isoetifolium</i> Species of aquatic plant

Syringodium isoetifolium, commonly known as noodle seagrass, is a species of flowering plant in the family Cymodoceaceae, growing underwater in marine habitats. It forms seagrass meadows in shallow sandy or muddy locations in the Indian and Pacific Oceans.

References

  1. Short, F.T.; Waycott, M. (2010). "Enhalus acoroides". IUCN Red List of Threatened Species . 2010: e.T173331A6992567. doi: 10.2305/IUCN.UK.2010-3.RLTS.T173331A6992567.en . Retrieved 13 November 2021.
  2. Mem. Inst. Par. ii. (1811) (Math.-Phys.)., 64. (Index Kewensis)
  3. Illustrations of the Botany of the Himalayan Mountains 1 1839 (APNI)
  4. Kew World Checklist of Selected Plant Families
  5. 1 2 3 Larkum, Anthony W.D.; Duarte, Carlos; Orth, Robert J., eds. (2005). "Taxonomy and biogeorgraphy of seagrasses". Seagrasses: Biology, Ecology and Conservation. Springer-Verlag New York, LLC. ISBN   978-1-4020-2942-4.
  6. 1 2 Phillips, R.C. and E.G. Meñez. 1988. Seagrasses. Smithsonian Contrib. Mar. Sci. 34, 104 pp.
  7. Duarte, Carlos M. (November 26, 1991). "Allometric scaling of seagrass form and productivity" (PDF). int-res.com.
  8. 1 2 BROUNS AND HEIJS, JOOP AND FRANCIEN (December 17, 1986). "STRUCTURAL AND FUNCTIONAL ASPECTS OF SEAGRASS COMMUNITIES AND ASSOCIATED ALGAE FROM THE TROPICAL WEST-PACIFIC" (PDF).
  9. IUCN (2007-10-17). "Enhalus acoroides: Short, F.T. & Waycott, M.: The IUCN Red List of Threatened Species 2010: e.T173331A6992567". IUCN Red List of Threatened Species . 2007-10-17. doi: 10.2305/iucn.uk.2010-3.rlts.t173331a6992567.en .
  10. 1 2 3 4 Rollon, Rene N. (March 10, 1998). "Spatio-temporal variation in shoot size and leaf growth of the two dominant Philippine seagrasses Enhalus acoroides (L.f.) Royle and Thalassia hemprichii (Ehrenb.) Aschers". balkema.nl.