Définition : Common species and uncommon species are designations used in ecology to describe the population status of a species. Commonness is closely related to abundance. Abundance refers to the frequency with which a species is found in controlled samples; in contrast, species are defined as common or uncommon based on their overall presence in the environment. A species may be locally abundant without being common.
Définition : Stress tolerant species live in areas of high intensity stress and low intensity disturbance. Species that have adapted this strategy generally have slow growth rates, high rates of nutrient retention, and low phenotypic plasticity. Stress tolerators respond to environmental stresses through physiological variability. These species are often found in stressful environments.
Définition : Appendix II lists species that are not necessarily now threatened with extinction but that may become so unless trade is closely controlled. It also includes so-called "look-alike species", i.e. species whose specimens in trade look like those of species listed for conservation reasons. International trade in specimens of Appendix-II species may be authorized by the granting of an export permit or re-export certificate. No import permit is necessary for these species under CITES (although a permit is needed in some countries that have taken stricter measures than CITES requires). Permits or certificates should only be granted if the relevant authorities are satisfied that certain conditions are met, above all that trade will not be detrimental to the survival of the species in the wild. (See Article IV of the Convention)
Définition : A taxon is Least Concern when it has been evaluated against the criteria and does not qualify for Critically Endangered, Endangered, Vulnerable or Near Threatened. Widespread and abundant taxa are included in this category.
Définition : Living in the fluid medium (water or air) but unable to maintain their position or distribution independently of the movement of the water/air mass (adapted from Lincoln et al., 1998).
Définition : Marine sediment that accumulates within shallow regions of the oceanic basin close to continents, such as the continental shelf, or continental slope
Définition : 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. The former type may have been the first step toward multicellular organisms
Définition : The marine benthic biome (benthic meaning 'bottom') encompasses the seafloor and includes such areas as shores, littoral or intertidal areas, marine coral reefs, and the deep seabed.
Définition : A depression caused by erosion by water or ice. Low-lying land bordered by higher ground; especially elongate, relatively large gently sloping depressions of the Earth's surface, commonly situated between two mountains or between ranges of hills or mountains, and often containing a stream with an outlet.
Définition : Capable of the biological process in which new individuals are produced by either a single cell or a group of cells, in the absence of any sexual process.
Définition : Capable of the biological process in which new individuals are produced by either a single cell or a group of cells, in the absence of any sexual process.
Définition : Capable of creating a new organism by combining the genetic material of two gametes, which may come from two parent organisms or from a single organism, in the case of self-fertilizing hermaphrodites.
Définition : A structural quality inhering in a bearer by virtue of the bearer's being thicker or more closely packed together; pressed tightly together.
