Results for “population”

population

Group of individuals of a given taxon occupying a particular geographic area or specified habitat.

Used in 487 profiles

viable population

A population of fish in a state that maintains its potential for survivial and evolutionary change.

Used in 2 profiles

biological species concept

Most popular concept of species in vertebrate zoology. Defines species as members of populations that do or potentially could interbreed and produce fertile offspring in nature, regardless of appearance, therefore somewhat more restrictive than the phylogenetic species concept. In theory species are thus separated from one another by some form of reproductive isolation, though in practice this does not always hold true. Often abbreviated to BSC.

natural selection

Term introduced by Charles Darwin referring to the nonrandom mechanism of evolution by which certain biological traits become either more or less common in a population due to differential, environmentally-influenced reproduction. Better-adapted individuals tend to produce more offspring, thus the population evolves, and this process can result in populations that gradually become specialised to inhabit particular ecological niches and can eventually result in the emergence of new species.

depensation

Reduction in breeding population size leading to reduced fecundity in the overall population or stock of a species.

subspecies

Taxonomic rank below species, written in the form of a trinomen. Often applied to a geographically-separated population within a species that retains the capability to produce fertile offspring with other populations but may exhibit phenotypic differences.

Used in 78 profiles

aff.

Abbreviation of the word 'affinis', meaning related but not identical to. Used in the fields of systematics and taxonomy when referring to undescribed specimens or populations that resemble, but are clearly different to, a described species.

algae shrimp

Somewhat misleading vernacular name for the freshwater shrimp Caridina multidentata Stimpson 1860, a popular addition to freshwater aquaria due to its reputation for consuming algae, though in reality it is unable to survive on a diet of algae alone. Formerly referred to as C. japonica De Man 1892 (that name is now regarded as a junior synonym of C. multidentata) and also known as the Amano shrimp. Exhibits an amphidromous life cycle in nature and is thus difficult to breed in captivity, though it has been achieved.

algal bloom

A population explosion of unicellular algae, normally resulting from an increase or excess of available nutrients.

Used in 3 profiles

allopatric

Occurring in separate, nonoverlapping geographic areas. Often used to refer to geographically-separated, reproductively-isolated populations of related organisms. Opposite of sympatric.

Used in 2 profiles

aragonite

Naturally-occurring, crsytalline form of calcium carbonate with a notable buffering capacity. Popular as a substrate or substrate additive in marine and freshwater aquaria where pH and hardness must be maintained at high levels, and has a more rapid, effective effect than coral sand, for example.

Artemia

Commonly known as brine shrimp; a genus of phyllopod crustacean inhabiting salt lakes and brines. Cultivated as food for aquarium fishes and available live, frozen or freeze-dried. Its newly-hatched nauplii are also a popular food for fish fry.

Used in 1,159 profiles

biomass

The total mass of living matter present in a given individual, habitat, population, or sample.

biotope

An area of uniform environmental conditions and species distribution containing a specific assemblage of plants and animals. Similar to 'habitat' but refers to a biological community rather than a single species or population.

Used in 313 profiles

bloom

A population explosion of phytoplankton such as algae.

Used in 16 profiles

C number

Coding system used to organise and refer to unidentified catfishes, though not necessarily undescribed or distinct species, of the genus Corydoras. Works in tandem with the similar CW number system. The system was invented by German aquarist Hans-Georg Evers and first appeared in the magazine 'DATZ' but is now in popular use worldwide.

Used in 67 profiles

cf.

Abbreviation of the word 'confer', meaning 'compare with'. Used in the fields of systematics and taxonomy to denote specimens or populations that resemble a described taxon but differ in some respects and thus may or may not represent a distinct species.

community

A group of organisms or populations coexisting and interacting with one another in a given region under relatively similar environmental conditions. The different organisms influence each other's abundance, distribution, and evolutionary adaptation.

Used in 875 profiles

CW number

Coding system used to organise and refer to unidentified catfishes, though not necessarily undescribed or distinct species, of the genus Corydoras. Works in tandem with the similar C number system. The system was invented by Ian A. M. Fuller in reference to his website 'Corydoras World' but is now in popular use worldwide.

Used in 65 profiles

ecotype

A distinct population of a species adapted to occupy a particular habitat due to localised natural selection.