{{Short description|Living things grouping together, usually for common benefit}} {{For|the political term|Colony}}
[[File:Phalacrocorax penicillatus (Brandt's Cormorant) colony, Point Lobos - Diliff.jpg|thumb|350px|A colony of Brandt's cormorants in Point Lobos, California]]
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 prey.<ref name=Jackson1977>{{cite journal|doi=10.1086/283203|title= Competition on Marine Hard Substrata: The Adaptive Significance of Solitary and Colonial Strategies|year=1977|last1=Jackson|first1=J.B.C.|journal=The American Naturalist|volume=111|issue=980|pages=743–767|bibcode= 1977ANat..111..743J|s2cid= 84687243}}</ref>
Colonies can form in various shapes and ways depending on the organism involved. For instance, the '''bacterial colony''' is a cluster of identical cells (clones). These colonies often form and grow on the surface of (or within) a solid medium, usually derived from a single parent cell.<ref>{{Cite web|url=http://www.biology-online.org/dictionary/Colony|title=Colony – Biology-Online Dictionary|website=www.biology-online.org|language=en|access-date=2017-05-06}}</ref>
Colonies, in the context of development, may be composed of two or more unitary (or solitary) organisms or be modular organisms. '''Unitary organisms''' have determinate development (set life stages) from zygote to adult form and individuals or groups of individuals (colonies) are visually distinct. '''Modular organisms'''<ref>{{Cite journal|last1=Hiebert|first1=Laurel S.|last2=Simpson|first2=Carl|last3=Tiozzo|first3=Stefano|date=2020-04-19|title=Coloniality, clonality, and modularity in animals: The elephant in the room|journal=Journal of Experimental Zoology Part B: Molecular and Developmental Evolution|volume=336|issue=3|language=en|pages=198–211|doi=10.1002/jez.b.22944|pmid=32306502|s2cid=216030034|issn=1552-5007|url=https://hal.archives-ouvertes.fr/hal-02982659/file/Coloniality.pdf}}</ref> have indeterminate growth forms (life stages not set) through repeated iteration of genetically identical modules (or individuals), and it can be difficult to distinguish between the colony as a whole and the modules within.<ref>{{cite book | display-authors=1 | first1=Michael | last1=Begon | first2=Robert W. | last2=Howarth | first3=Colin R. | last3=Townsend | title=Essentials of Ecology | edition=4th | publisher=Wiley | year=2014 | isbn=978-0-470-90913-3}}</ref> In the latter case, modules may have specific functions within the colony.
In contrast, solitary organisms{{snd}}such as jaguars{{snd}}do not associate with colonies; they are ones in which all individuals live independently and have all of the functions needed to survive and reproduce.
Some organisms are primarily independent and form facultative colonies in reply to environmental conditions while others must live in a colony to survive (obligate). For example, some carpenter bees will form colonies when a dominant hierarchy is formed between two or more nest foundresses<ref name="DunnRichards2003">{{cite journal|doi=10.1093/beheco/14.3.417|title= When to bee social: interactions among environmental constraints, incentives, guarding, and relatedness in a facultatively social carpenter bee|year=2003|last1=Dunn|first1=T.|last2=Richards|first2=M.H.|journal=Behavioral Ecology|volume=14|issue=3|pages=417–424|doi-access=free}}</ref> (facultative colony), while corals are animals that are physically connected by living tissue (the coenosarc) that contains a shared gastrovascular cavity.
== Types == === Social colonies === [[Image:Apis florea nest.JPG|thumb|right|''Apis florea'' colony, Thailand. The nest is 20 cm in diameter and contains approximately 3600 cells on each side. The curtain of bees covering the comb with the queen is 3–4 bees thick (~10 mm).]] Unicellular and multicellular unitary organisms may aggregate to form colonies. For example, * Protists such as slime molds are many unicellular organisms that aggregate to form colonies when food resources are hard to come by, as together they are more reactive to chemical cues released by preferred prey. * Eusocial insects like ants and honey bees are multicellular animals that live in colonies with a highly organized social structure. Colonies of some social insects may be deemed superorganisms.<ref>{{cite journal |last1=Canciani |first1=M. |last2=Arnellos |first2=A. |last3=Moreno |first3=A. |date=2019 |title=Revising the Superorganism: An Organizational Approach to Complex Eusociality |journal=Frontiers in Psychology |volume=10 |page= Article 2653 |article-number=2653 |doi=10.3389/fpsyg.2019.02653 |pmid=31849768 |pmc=6901679 |doi-access=free }}</ref> * Some animals, including various species of birds and mammals, form breeding or nesting colonies, potentially for more successful mating and to better protect offspring. ** The Bracken Cave is the summer home to a colony of around 20 million Mexican free-tailed bats, making it the largest known concentration of mammals.<ref name=natgeo>{{cite journal | title = Quietly Conserving Nature | last = Grove | first = Noel | journal = National Geographic | date = December 1988 | volume = 174 | issue = 6 | page = 822}}</ref>
=== Modular organisms === [[File:Marrus orthocanna.jpg|thumb| The pelagic ''Marrus orthocanna'' is a colonial siphonophore assembled from two types of zooids]] Modular organisms are those in which a genet (or genetic individual formed from a sexually-produced zygote) asexually reproduces to form genetically identical clones called ramets.<ref name=Winston2010>{{cite journal|doi=10.1093/icb/icq146|title= Life in the Colonies: Learning the Alien Ways of Colonial Organisms|year=2010|last1=Winston|first1=J.|journal=Integrative and Comparative Biology|volume=50|issue=6|pages=919–933|pmid=21714171|doi-access=free}}</ref> ====Clonal colony====
A clonal colony a group of ramets from one genet that live in close proximity or are physically connected. Ramets may have all of the functions needed to survive on their own or be interdependent on other ramets. For example, some sea anemones go through the process of pedal laceration in which a genetically identical individual is asexually produced from tissue broken off from the anemone's pedal disc. In plants, clonal colonies are created through the propagation of genetically identical individuals by stolons or rhizomes.
====Colonial organisms====
Colonial organisms are clonal colonies composed of many physically connected, interdependent individuals. The subunits of colonial organisms can be unicellular, as in the alga ''Volvox'' (a coenobium), or multicellular, as in the phylum Bryozoa. Colonial organisms may have been the first step toward multicellular organisms.<ref>{{cite book | display-authors=1 | first1=Bruce | last1=Alberts | first2=Dennis | last2=Bray | first3=Julian | last3=Lewis | first4=Martin | last4=Raff | first5=Keith | last5=Roberts | first6=James D. | last6=Watson | title=Molecular Biology of the Cell | edition=3rd | location=New York | publisher=Garland Science | year=1994 | isbn=0-8153-1620-8 | url=https://archive.org/details/molecularbiology00albe | access-date=2014-06-11 | url-access=registration }}</ref> Individuals within a multicellular colonial organism may be called ramets, modules, or zooids. Structural and functional variation (polymorphism), when present, designates ramet responsibilities such as feeding, reproduction, and defense. To that end, being physically connected allows the colonial organism to distribute nutrients and energy obtained by feeding zooids throughout the colony. The hydrozoan Portuguese man o' war is a classic example of a colonial organism, one of many in the taxonomic class.<ref>{{Cite web|url=http://animaldiversity.org/accounts/Hydrozoa/|title=Hydrozoa|website=Animal Diversity Web|language=en|access-date=2017-05-06}}</ref>
=== Microbial colonies === [[File:Candida albicans PHIL 3192 lores.jpg|thumb|Clonal micro colonies of the fungus Candida albicans on an agar plate]] A '''microbial colony''' is defined as a visible cluster of microorganisms growing on the surface of or within a solid medium, presumably cultured from a single cell.<ref>{{Cite book | last1 = Tortora | first1 = Gerard J. | first2 = Funke | last2 = Berdell R. | first3 =Case | last3 = Christine L. | title = Microbiology, An Introduction | location = Berlin | publisher = Benjamin Cummings | year= 2009 | pages = 170–171 | isbn = 978-0-321-58420-5 }}</ref> Because the colony is clonal, with all organisms in it descending from a single ancestor (assuming no contamination), they are genetically identical, except for any mutations (which occur at low frequencies). Obtaining such genetically identical organisms (or pure strains) can be useful; this is done by spreading organisms on a culture plate and starting a new stock from a single resulting colony.<ref>{{cite journal |last1=Sanders |first1=E.R. |date=2012 |title=Aseptic Laboratory Techniques: Plating Methods |url=https://www.jove.com/t/3064/aseptic-laboratory-techniques-plating-methods |journal=Journal of Visualized Experiments |issue=63 |article-number=e3064 |doi=10.3791/3064 |pmid=22617405 |pmc=4846335 }}</ref>
A '''biofilm''' is a colony of microorganisms often comprising several species, with properties and capabilities greater than the aggregate of capabilities of the individual organisms.<ref>{{cite journal |last1=Nadell |first1=Carey D. |last2=Xavier |first2=Joao B. |last3=Foster |first3=Kevin R. |title=The sociobiology of biofilms |journal=FEMS Microbiology Reviews |date=January 2009 |volume=33 |issue=1 |pages=206–224 |doi=10.1111/j.1574-6976.2008.00150.x |pmid=19067751 |url=https://academic.oup.com/femsre/article/33/1/206/2683812?login=false|url-access=subscription }}</ref>
==Ontogeny in eusocial insects== Colony ontogeny refers to the developmental process and progression of a colony. It describes the various stages and changes that occur within a colony from its initial formation to its mature state.<ref>{{cite journal |last=Jeanne |first=R. L. |year=1986 |title=The evolution of the organization of work in social insects |journal=Monitore Zoologico Italiano-Italian Journal of Zoology |volume=20 |pages=119–133}}</ref> The exact duration and dynamics of colony ontogeny can vary greatly depending on the species and environmental conditions.<ref>{{cite journal |last=Keller |first=L. |year=1998 |title=Queen lifespan and colony characteristics in ants and termites |journal=Insectes Sociaux |volume=45 |issue=3 |pages=235–246|doi=10.1007/s000400050084 |s2cid=24541087 }}</ref><ref>{{cite journal |last1=Keller |first1=L. |last2=Genoud |first2=M. |year=1997 |title=Extraordinary lifespans in ants: A test of evolutionary theories of ageing |journal=Nature |volume=389 |issue=6654 |pages=958–960|doi=10.1038/40130 |bibcode=1997Natur.389..958K |s2cid=4423161 |url=https://serval.unil.ch/notice/serval:BIB_8F93055ACAEF }}</ref> Factors such as resource availability, competition,<ref>{{cite journal |last1=Cronin |first1=Adam L. |last2=Fédérici |first2=Pierre |last3=Doums |first3=Claudie |last4=Monnin |first4=Thibaud |title=The influence of intraspecific competition on resource allocation during dependent colony foundation in a social insect |journal=Oecologia |date=1 February 2012 |volume=168 |issue=2 |pages=361–369 |doi=10.1007/s00442-011-2098-6 |pmid=21833638 |bibcode=2012Oecol.168..361C |url=https://link.springer.com/article/10.1007/s00442-011-2098-6 |language=en |issn=1432-1939|url-access=subscription }}</ref> and environmental cues can influence the progression and outcome of colony development.<ref>{{cite journal |last1=Chouvenc |first1=Thomas |last2=Basille |first2=Mathieu |last3=Li |first3=Hou-Feng |last4=Su |first4=Nan-Yao |title=Developmental Instability in Incipient Colonies of Social Insects |journal=PLOS ONE |date=25 November 2014 |volume=9 |issue=11 |article-number=e113949 |doi=10.1371/journal.pone.0113949 |doi-access=free |pmid=25423502 |pmc=4244189 |bibcode=2014PLoSO...9k3949C |language=en |issn=1932-6203}}</ref>
During colony ontogeny for eusocial insects such as ants and bees, a colony goes through several distinct phases, each characterised by specific behavioural patterns, division of labor, and structural modifications. While the exact details can vary depending on the species, the general progression typically involves a number of well-defined stages, detailed below.<ref>{{cite journal |last=Bourke |first=A. F. G. |year=1999 |title=Colony size, social complexity and reproductive conflict in social insects |journal=Journal of Evolutionary Biology |volume=12 |issue=2 |pages=245–257|doi=10.1046/j.1420-9101.1999.00028.x |s2cid=85187599 |doi-access=free }}</ref><ref>{{cite book |last1=Alexander |first1=R. D. |last2=Noonan |first2=K. M. |last3=Crespi |first3=B. J. |year=1991 |title=The evolution of eusociality |editor1-first=N. G. |editor1-last=Jablonski |editor2-first=V. |editor2-last=Jain |editor3-first=H. |editor3-last=Jarchow |editor4-first=P. |editor4-last=Schulze-Makuch |editor5-first=T. |editor5-last=Deutsch |series=The biology of the naked mole-rat |volume=3 |page=44}}</ref>
===Founding stage=== In this initial stage, a single female individual or small group of female individuals, often called the foundress(es), queen(s) (and kings for termites) or primary reproductive(s), establish a new colony. The foundresses build a basic nest structure and begin to lay eggs. The foundresses can also perform non-reproductive tasks at this early stage, such as nursing these first eggs and leaving the nest to gather resources.
===Worker emergence=== This is also known as the ergonomic stage. As the eggs laid by the foundresses develop, they give rise to the first generation of workers. These workers can assume various tasks, such as foraging, brood care, and nest maintenance. Initially, the worker population is relatively small, and their tasks are not as specialised. As the colony grows, more workers emerge, and the division of labor becomes more pronounced. Some individuals may specialise in tasks like foraging, defense, or tending to the brood, while others may take on general tasks within the nest.<ref>{{cite journal |last1=Friedmann |first1=D. |last2=Johnson |first2=B. |last3=Linksvayer |first3=T. |year=2020 |title=Distributed physiology and the molecular basis of social life in eusocial insects |journal=Hormones and Behavior |volume=122 |article-number=104757 |doi=10.1016/j.yhbeh.2020.104757 |pmid=32305342 |s2cid=216030233 |doi-access=free }}</ref> These specialised tasks can change throughout the life of a worker.
===Reproductive phase=== At a certain point in the colony ontogeny, usually after a period of growth and maturation, the colony produces reproductives, including new virgin queens (princesses) and males. These individuals have the potential to leave the nest and start new colonies, ensuring the transmission of the gene pool of its natal colony.
===Colony death=== Over time, colonies may go through a senescence phase where the reproductive output declines, and the colony's overall vitality diminishes. Eventually, the colony may die off or be replaced by a new generation of reproductives. After the death of the queen in a monogyne colony, possible fates other than colony death include serial polygyny (when a virgin queen of the colony replaces the dead queen as the primary reproductive) or colony inheritance (when a worker takes over as primary reproductive).{{cn|date=November 2023}}
== Life history ==
Individuals in social colonies and modular organisms receive benefit to such a lifestyle. For example, it may be easier to seek out food, defend a nesting site, or increase competitive ability against other species. Modular organisms' ability to reproduce asexually in addition to sexually allows them unique benefits that social colonies do not have.<ref name="Winston2010" />
The energy required for sexual reproduction varies based on the frequency and length of reproductive activity, number and size of offspring, and parental care.<ref name=KunzOrrell>{{cite journal|title= Energy Costs of Reproduction|year=2004|last1=Kunz|first1=T.H.|last2=Orrell|first2=K.S.|journal=Encyclopedia of Energy|volume=5|pages=423–442|doi=10.1016/B0-12-176480-X/00061-9}}</ref> While solitary individuals bear all of those energy costs, individuals in some social colonies share a portion of those costs.{{cn|date=November 2023}}
Modular organisms save energy by using asexual reproduction during their life. Energy reserved in this way allows them to put more energy towards colony growth, regenerating lost modules (due to predation or other cause of death), or response to environmental conditions.{{cn|date=November 2023}}
== See also == {{Wiktionary|colony}} {{col div|colwidth=30em}} * Ant colony * Bee colony * Bird colony * Clonal colony * Coenocyte * Colonisation (biology) * Coral reef * Eusociality * Superorganism * Swarm * Birth colony * ''Austroplatypus incompertus'' {{colend}}
== References == <references />
Category:Community ecology Category:Microbiology terms Category:Habitat Category:Environmental terminology