In limnology

Limnology

Limnology , also called freshwater science, is the study of inland waters. It is often regarded as a division of ecology or environmental science. It covers the biological, chemical, physical, geological, and other attributes of all inland waters...

, sessility is that quality of an organism which rests unsupported directly on a base, either attached or unattached to a substrate

Substrate (marine biology)

Stream substrate is the material that rests at the bottom of a stream. There are several classification guides. One is:*Mud – silt and clay.*Sand – Particles between 0.06 and 2 mm in diameter.*Granule – Between 2 and 4 mm in diameter....

. It is a characteristic of vegetation which is anchored to the benthic environment. There are two families of sessile rotifer

Rotifer

The rotifers make up a phylum of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John Harris in 1696, and other forms were described by Anton van Leeuwenhoek in 1703...

s: Flosculariidae and Collothecidae. The circalittoral zone of coast

Coast

A coastline or seashore is the area where land meets the sea or ocean. A precise line that can be called a coastline cannot be determined due to the dynamic nature of tides. The term "coastal zone" can be used instead, which is a spatial zone where interaction of the sea and land processes occurs...

al environments and biome

Biome

Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...

s are dominated by sessile organisms such as oyster

Oyster

The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....

s. Carbonate platform

Carbonate platform

A carbonate platform is a sedimentary body which possesses topographic relief, and is composed of autochthonous calcareous deposits . Platform growth is mediated by sessile organisms whose skeletons build up the reef or by organisms which induce carbonate precipitation through their metabolism...

s grow due to the buildup of skeletal remains of sessile organisms, usually microorganism

Microorganism

A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...

s, which induce carbonate precipitation through their metabolism.

Sessile organisms such as barnacle

Barnacle

A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...

s and tunicate

Tunicate

Tunicates, also known as urochordates, are members of the subphylum Tunicata, previously known as Urochordata, a group of underwater saclike filter feeders with incurrent and excurrent siphons that is classified within the phylum Chordata. While most tunicates live on the ocean floor, others such...

s need some mechanism to move their young into new territory. This is why the most widely accepted theory explaining the evolution

Evolution

Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

 of a larva

Larva

A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

l stage is the need for long-distance dispersal ability. Wayne Sousa

Wayne Sousa

Wayne Sousa is a well-known biologist and ecologist. He works at the University of California, Berkeley as a professor and chair of the Department of Integrative Biology. His research in community ecology has been in two broad areas: the role of disturbance in structuring natural communities and...

's 1979 study in intertidal disturbance added support for the theory of nonequilibrium community structure, “suggesting that open space is necessary for the maintenance of diversity in most communities of sessile organisms.”

See also

• Sessility (botany)
  Sessility (botany)
  In botany, sessility is a characteristic of plants whose flowers or leaves are borne directly from the stem or peduncle, and thus lack a petiole or pedicel...
  
  , flowers or leaves that grow directly from the stem or peduncle of a plant
• Sessility (medicine)
  Sessility (medicine)
  In medicine, sessility is a characteristic of tumors and polyps that lack a stalk, as opposed to those that are pedunculated....
  
  , tumors and polyps that lack a stalk
• Sessility (zoology)
  Sessility (zoology)
  In zoology, sessility is a characteristic of animals which are not able to move about. They are usually permanently attached to a solid substrate of some kind, such as a part of a plant or dead tree trunk, a rock, or the hull of a ship in the case of barnacles. Corals lay down their own...
  
  , animals which are not able to move about