Sessility is the biological property of an organism describing its lack of a means of self-locomotion. Sessile organisms for which natural motility is absent are normally immobile. This is distinct from the botanical concept of sessility, which refers to an organism or biological structure attached directly by its base without a stalk.
Sessile organisms can move via external forces (such as water currents), but are usually permanently attached to something. Organisms such as corals lay down their own substrate from which they grow. Other sessile organisms grow from a solid such as a rock, dead tree trunk, or a man-made object such as a buoy or ship's hull.[1]
Sessile animals typically have a motile phase in their development. Sponges have a motile larval stage and become sessile at maturity. Conversely, many jellyfish develop as sessile polyps early in their life cycle. In the case of the cochineal, it is in the nymph stage (also called the crawler stage) that the cochineal disperses. The juveniles move to a feeding spot and produce long wax filaments. Later they move to the edge of the cactus pad where the wind catches the wax filaments and carries the tiny larval cochineals to a new host.
Reproduction
Many sessile animals, including sponges, corals and hydra, are capable of asexual reproductionin situ by the process of budding. Sessile organisms such as barnacles and tunicates need some mechanism to move their young into new territory. This is why the most widely accepted theory explaining the evolution of a larval stage is the need for long-distance dispersal ability. Biologist Wayne Sousa'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".[2]
Blue mussels, Mytilus edulis, are sessile and exhibit clumping
Clumping is a behavior in sessile organisms in which individuals of a particular species group closely to one another for beneficial purposes, as can be seen in coral reefs and cochineal populations. This allows for faster reproduction and better protection from predators.[3]
^Sousa, Wayne P. (1979). "Disturbance in Marine Intertidal Boulder Fields: The Nonequilibrium Maintenance of Species Diversity". Ecology. 60 (6): 1225–1239. doi:10.2307/1936969.
^James H. Thorp; Alan P. Covich (2001). Ecology and Classification of North American Freshwater Invertebrates. Academic Press. p. 213. ISBN0-12-690647-5.
January 19, 2023
sessility, motility, other, uses, sessility, disambiguation, sessility, biological, property, organism, describing, lack, means, self, locomotion, sessile, organisms, which, natural, motility, absent, normally, immobile, this, distinct, from, botanical, concep. For other uses see Sessility disambiguation Sessility is the biological property of an organism describing its lack of a means of self locomotion Sessile organisms for which natural motility is absent are normally immobile This is distinct from the botanical concept of sessility which refers to an organism or biological structure attached directly by its base without a stalk Generally sessile Hydra attached to a substrate Sessile organisms can move via external forces such as water currents but are usually permanently attached to something Organisms such as corals lay down their own substrate from which they grow Other sessile organisms grow from a solid such as a rock dead tree trunk or a man made object such as a buoy or ship s hull 1 Contents 1 Mobility 2 Reproduction 3 Clumping 4 Predominance in coastal environments 5 Botanical sessility 6 See also 7 ReferencesMobility EditSessile animals typically have a motile phase in their development Sponges have a motile larval stage and become sessile at maturity Conversely many jellyfish develop as sessile polyps early in their life cycle In the case of the cochineal it is in the nymph stage also called the crawler stage that the cochineal disperses The juveniles move to a feeding spot and produce long wax filaments Later they move to the edge of the cactus pad where the wind catches the wax filaments and carries the tiny larval cochineals to a new host Reproduction EditMany sessile animals including sponges corals and hydra are capable of asexual reproduction in situ by the process of budding Sessile organisms such as barnacles and tunicates need some mechanism to move their young into new territory This is why the most widely accepted theory explaining the evolution of a larval stage is the need for long distance dispersal ability Biologist Wayne Sousa 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 2 Clumping EditMain article Clumping biology Blue mussels Mytilus edulis are sessile and exhibit clumping Clumping is a behavior in sessile organisms in which individuals of a particular species group closely to one another for beneficial purposes as can be seen in coral reefs and cochineal populations This allows for faster reproduction and better protection from predators 3 Predominance in coastal environments EditThe circalittoral zone of coastal environments and biomes are dominated by sessile organisms such as oysters Carbonate platforms grow due to the buildup of skeletal remains of sessile organisms usually microorganisms which induce carbonate precipitation through their metabolism Botanical sessility EditIn anatomy and botany sessility refers to an organism or biological structure that has no peduncle or stalk A sessile structure has no stalk See peduncle anatomy peduncle botany and sessility botany See also EditAnthozoa Ediacara biotaReferences Edit Pechenik Jan 2016 Biology of the Invertebrates ISBN 9781497006515 Sousa Wayne P 1979 Disturbance in Marine Intertidal Boulder Fields The Nonequilibrium Maintenance of Species Diversity Ecology 60 6 1225 1239 doi 10 2307 1936969 James H Thorp Alan P Covich 2001 Ecology and Classification of North American Freshwater Invertebrates Academic Press p 213 ISBN 0 12 690647 5 Retrieved from https en wikipedia org w index php title Sessility motility amp oldid 1134237192, wikipedia, wiki, book, books, library,
