''Zoanthus sociatus'', commonly known as the green sea mat or button polyp, is a zoanthid usually found in shallow reef zones of tropical regions from

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

southeastern Brazil The Southeast Region of Brazil ( ) is composed of the states of Espírito Santo, Minas Gerais, Rio de Janeiro (state), Rio de Janeiro and São Paulo State, São Paulo. It is the richest region of the country, responsible for approximately 53% of t ...

. ''Z. sociatus'' is currently being studied for its use against human

lymphatic Lymph () is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to be recirculated. At the origi ...

parasites.

Taxonomy

''Zoanthus sociatus'' has

nematocyst A cnidocyte (also known as a cnidoblast) is a type of cell containing a large secretory organelle called a ''cnidocyst'', that can deliver a sting to other organisms as a way to capture prey and defend against predators. A cnidocyte explosively ...

s, which makes it a

cnidaria Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...

n. As it has polyp morphology, it is an

anthozoan Anthozoa is one of the three subphyla of Cnidaria, along with Medusozoa and Endocnidozoa. It includes sessile marine invertebrates and invertebrates of brackish water, such as sea anemones, stony corals, soft corals and sea pens. Almost all ...

. It also has tentacles in multiples of 6, so it falls under the subclass

Hexacorallia Hexacorallia is a Class (biology), class of Anthozoa comprising approximately 4,300 species of aquatic organisms formed of polyp (zoology), polyps, generally with 6-fold symmetry. It includes all of the stony corals, most of which are Colony (b ...

. It is in the order Zoanthidea due to its lack of a calcium carbonate skeleton. Forms elaborate piecemeal mats of normally green to turquoise polyps. They are often found on reef flats exposed to high light intensity and intermittently strong currents.

Stolon In biology, a stolon ( from Latin ''wikt:stolo, stolō'', genitive ''stolōnis'' – "branch"), also known as a runner, is a horizontal connection between parts of an organism. It may be part of the organism, or of its skeleton. Typically, animal ...

-connected polyps normally have 30 short tentacles, polyps are extended continuously day and night and feed predominantly on

detritus In biology, detritus ( or ) is organic matter made up of the decomposition, decomposing remains of organisms and plants, and also of feces. Detritus usually hosts communities of microorganisms that colonize and decomposition, decompose (Reminera ...

, not

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

Habitat

''Z. Sociatus'' can be found in the lower

intertidal The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various sp ...

and upper subtidal zones on protected Caribbean reefs. It is a

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

colonial organism In biology, a colony is composed of two or more conspecific individuals living in close association with, or connected to, one another. This association is usually for mutual benefit such as stronger defense or the ability to attack bigger pre ...

. ''Z. sociatus'' grows in the reef

understory In forestry and ecology, understory (American English), or understorey (English in the Commonwealth of Nations, Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the Canopy (biology), forest ca ...

and on disturbed substrate. Z. sociatus can survive desiccation (an excessive loss of moisture) and lower levels of salinity. It appears to dominate other zoanthids.

Reproduction

Reproduction in ''Z. sociatus'' is mainly

asexual Asexual or Asexuals may refer to: *Asexual reproduction **Asexual reproduction in starfish *Asexuality, the lack of sexual attraction to anyone or lack of interest in or desire for sexual activity. **Gray asexuality, the spectrum between asexualit ...

although sexual reproduction may happen as well. There is extratentacular

budding Budding or blastogenesis is a type of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. For example, the small bulb-like projection coming out from the yeast cell is kno ...

, which is the creation of a new polyp from an old polyp, and fission, which is when a new fragment is formed. The size of a fragment is also controlled by the increasing rate of mortality with decreasing fragment size. A colony is generally genetically the same. Even when a colony is sexually reproductive, a large proportion of polyps remain infertile, which demonstrates the greater importance of asexual reproduction and growth. ''Z. sociatus'' colonies do not become reproductive until they reach a certain size. They use external fertilization, and are mostly hermaphroditic, although some are male or protogynous (female and then male). ''Z. sociatus'' was found to reproduce seasonally in Panama, and synchronizes the release of gametes with extremely low tides.

Diet

''Z. sociatus'' polyps obtain nearly half of their required energy from the zooxanthellae, organism that ''Z. Sociatus'' forms symbiosis with. Therefore, the rest of the energy must be obtained through feeding. Zoanthids have nematocysts on their mesenterial filaments that are used for prey capture. ''Z. sociatus'' will eat mostly anything that is the right size such as from Artemia cysts and dissolved organic matter. While zoanthids are less efficient heterotrophs, they produce more energy photosynthetically due to their lack of a calcified skeleton. The lack of a skeleton allows more light to reach the chloroplasts. To digest prey, it uses both

extracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...

and

intracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...

methods.

References

*http://www.advancedaquarist.com/issues/feb2003/invert.htm *http://www.sealifebase.org/summary/speciessummary.php?id=44798 *https://www.thecephalopodpage.org/MarineInvertebrateZoology/zoanthussociatus.html *http://www.ingentaconnect.com/content/umrsmas/bullmar/1983/00000033/00000001/art00009 *http://onlinelibrary.wiley.com/doi/10.1002/bscb.19810900913/abstract sociatus Animals described in 1786 {{Hexacorallia-stub