By Beatrice Franklin,2014-08-11 06:53
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     Glossary of biogeographic terms




    R.K. Johnson, B.J. Zahuranec*, D. Boltovskoy** and

    A.C. Pierrot-Bults***

     formerly Grice Marine Laboratory University of Charleston, Charleston, SC 29412 USA

     Sadly Bob Johnson died before this Glossary was finished

    * U. S. Office of Naval Research, Arlington, VA 22217, USA

    ** Univerdidad de Buenos Aires, Buenos Aires, Argentina

    *** Zoological Museum Amsterdam, University of Amsterdam,The Netherlands

     This glossary of terms applicable to Pelagic Biogeography has been prepared as part of the work of SCOR Working Group 93, "Pelagic Biogeography." The decision to prepare such a glossary was made at the first meeting of the Working Group at Amsterdam, 6 - 8 November, 1990. The need to more clearly communicate and utilize common concepts and terminology was in fact evident at the First International Conference on Pelagic Biogeography, where it was not clear that workers were using such essential terms as “biogeography” to convey the same meaning. This Glossary is one attempt by Working Group 93 to address that problem.

     The terms are given in alphabetical order in English with a Spanish translation of the term only when the term and/or the spelling is different. An alphabetical list of Spanish terms is given at the end of this document. The descriptions are given only in English. This list can thus also serve as a dictionary for Spanish speaking people to find the right term in English.

     In preparation of this Glossary we have cast our net broadly and include terms applicable in aquatic biogeography sensu lato, including freshwater and

    coastal ecosystems.

     Please note the following abbreviations, used widely:

    cf confer: compare with definitions of terms that follow;

    eg exempli gratia for example;

    qv quod vide: definition for indicated (preceding) term will extend and clarify

     the present definition;

    syn synonym


     Glossary of biogeographic terms

     We have not attempted to list names, much less diagnoses, for the taxonomic groups that are the principal players in pelagic biogeography nor the proper names of pelagic biogeographic regions or provinces as used by various authors. To have done so would have greatly increased the size of the Glossary, we believe to the detriment of its usefulness.

     Every term we list can be found in use in the literature and defined elsewhere. We have invented nothing, save our own interpretation. The usefulness, if any, of this work is our deliberate effort to bring together terms from what are in fact connected but commonly disparate disciplinary areas - biological oceanography, phylogeny, ecology, physiology, ichthyology, evolutionary biology, physical oceanography, chemical oceanography, biogeography, meteorology, and others. We thank our colleagues for their help in improving this work. The choices and omissions, deliberate or not, as well as the errors, are our own.

“When I use a word,” Humpty Dumpty said in rather a scornful tone, “it means just what I

    choose it to mean—neither more nor less.”

Lewis Carroll (183298), English author, mathematician. Through the Looking-Glass, ch. 6 (1872).


     Glossary of biogeographic terms


abiotic factors

    factores abióticos

    (1) Physical or chemical parameters "forcing" (cf forcing functions) distribution patterns.

    (2) Nonliving forces or situations controlling or influencing the dynamics of living systems.



    Ecology: A measure of population density, the number, mass or weight of organisms present in a defined area or volume ( cf standing crop / standing stock; P/B ratio).



     (1) Pertaining to the zone of modal ocean basin depth, below 2000 m, lying seaward to and deeper than the bathyal (qv) zone.

    (2) Encompassing the ocean floor at depths between 2 and 6 km.

abyssal circulation

    circulación abisal

    Applies to large-scale oceanic water movement, density-driven, at depths between 2 and 6 km.



    A subdivision of the oceanic benthic environment at depths between 2 and 6 km.



    A subdivision of the oceanic pelagic environment occupying the strata between 2 and 6 km.

accepted name

    nombre aceptado

    Taxonomy: A name adopted by an author as the correct name for a taxon.

accidental species

    especie accidental

    Rare species in a community ( cf Braun-Blanquet classification ), either chance invaders from another community or relicts from a previous community (cf exclusive, indifferent,

    preferential, or selective species).



    Response of an animal that enables it to tolerate a change in a single factor in its environment

    (eg temperature). (cf acclimitization).


    aclimatación transitoria

    A reversible adaptive response that enables an organism to tolerate environmental change (eg seasonal climatic change).


     Glossary of biogeographic terms


    Of or pertaining to littoral rocky shores as habitat.

action spectrum

    espectro de acción

    Graphic depiction of the efficiency of different wave lengths of light in promoting a given photoresponse (eg in photosynthesis or phototropism).

active pool

    existencia activa

    A component of a biogeochemical (qv) cycle in which the nutrient or active substance

    exchanges rapidly between the biotic and abiotic components - usually smaller or much smaller than the reservoir pool (qv).



    (1) The condition of showing fitness (qv) for a particular environment, as applied to the

    characteristics of a structure, function, or entire organism.

    (2) The process by which fitness is acquired.

adaptive peaks and valleys

    valles y picos adaptativos

    Symbolic contour map showing relative Darwinian fitness or adaptive value of genotypic characters or characteristics, represented by adaptive peaks (high fitness) and valleys (low fitness).

adaptive radiation

    radiación adaptativa

    (1) Evolutionary divergence of members of a single phyletic line into a series of rather different niches or adaptive zones.

    (2) A burst of evolution with rapid divergence from a single ancestral form resulting in exploitation of an array of habitats (cf tachytelic, punctuated equilibria).

adaptive zone

    zona adaptativa

    Comprises the "living space" of a taxon in the associated environmental regime or regimes, habitat or niche. The adaptive specialization that fits the taxon to the given environmental circumstances may be broad or narrow (eg stenophagy vs omnivory).

adjacently sympatric

    simpátrico adyacente

    Of or pertaining to those aspects of a parapatric (qv) speciation event whereby the daughter

    species are minimally isolated geographically.


    Taxonomy: The form of a name which can be validly published and the use of a name in accordance with provisions of the applicable international code, such as the ICZN (qv) for



     Glossary of biogeographic terms



    Closely applied to; growing on; attached along entire length.



    (1) Mass motion in the atmosphere or ocean. In the ocean, the transport of water due to wind forcing or density driven circulation.

    (2) The transport of organisms or materials by large-scale water movement. (cf upwelling, convection).

affinity index

    índice de afinidad

    Measure of the relative similarity of the composition of two samples. Reciprocal affinity is a measure of distance.

age class

    clase de edad

    A category comprising individuals of a given age within a population; a cohort.

age-specific death rate

    tasa de mortalidad específica

    The death rate for a given age class in a population calculated as the number dying in age class

    x divided by the number that attain age class x; designated by l. x

age-specific fecundity rate

    tasa de fecundidad específica

    The average number of female young per female produced per unit time by an individual of specified age; designated by m. x


    especie agámica

    Species which replicate asexually.



    A contagious distribution (qv) in which values, observations or individuals are more clustered or grouped together than in a random (qv) distribution, indicating that the presence of one organism or value increases the probability of another occurring nearby. Also known as overdispersion (qv).



    (1) Oceanography: Inorganic or organic clumping of particles, with or without associated living organisms (cf marine snow).

    (2) Ecology: A group of individual items (soil particles, organisms, etc.) occurring together in


    cluster, in which the average inter-individual distance within the cluster is significantly less than the average inter-individual distance outside of the cluster.


     Glossary of biogeographic terms



    (1) The process of forming an aggregate or cluster.

    (2) A synonym for cluster.

    (3) A group of organisms that is formed when individuals are attracted or limited to a patchily

    distributed environmental resource (cf patchiness).


    Of or pertaining to a beach community.

agonistic behavior

    comportamiento antagónico

    Describes behavioral interaction between two rival organisms of the same species that may involve aggression, threat, appeasement, or avoidance, often involving stereotyped or ritual behavior.

air-sea interface

    interfase aire-agua

    The zone of contact between atmosphere and marine hydrosphere.


    Of or pertaining to shallow inshore environments and communities.



    Reflectivity (eg of the earth, atmosphere, sea surface, land surface) measured as a percentage of incident solar radiation.



    A finite series of logical steps or instructions by which a particular numerical or algebraic problem can be solved.



    The set of alternative gene forms at a given chromosomal locus.



    Release by an organism of a chemical substance into the environment that acts as an inhibitor to the germination or growth of another organism. Most common among plants and




    Occurring in two or more communities within a given geographical region.


     Glossary of biogeographic terms

allochronic speciation

    especiación alocrónica

    (1) Neontology: Speciation without geographical separation through the acquisition of different

    breeding seasons or patterns.

    (2) Paleontology: Speciation occurring by the sequential replacement of species through time.

allochronic species

    especie alocrónica

    Paleontology: Species which do not occur at the same time level (cf synchronic species).



    Not indigenous or native; acquired. May apply to species, food or nutrient input, or to sediment transported to be deposited within the system of reference.



    Differential rate of growth such that size of one part (or more) of the body changes in proportion to another part of the body or the whole, but at a constant exponential rate.

allopatric speciation

    especiación alopátrica

    Species formation during geographical isolation (cf sympatric speciation, centrifugal


    as a result of fragmentation of the original breeding population and subsequent genetic divergence of daughter populations (cf parapatric, dichopatric).



    (1) The condition of species or populations occupying mutually exclusive (but often adjacent) geographic areas (cf sympatry).

    (2) Applied to species that occupy separate habitats and do not co-occur as breeding adults in nature.



    Used of populations or species that occupy different macrohabitats (cf syntopic).



    Taxonomy: A paratype of different sex than the holotype and designated by the original author; has no formal ICZN status.



    Genetics: alternative forms of alleles at the same locus.


     Glossary of biogeographic terms

allozyme frequency

    frecuencia alozímica

    Allozyme frequency is the total number of times a given allozyme is detected among individuals in a sample, divided by sample size. By "one gene, one enzyme", allozyme frequency (where detectable and not modified by nongenetic factors) provides a direct index of allelic frequency at a given locus.

alpha taxonomy

    taxonomía descriptiva

    Descriptive taxonomy (qv), concerned primarily with the recognition and description of species, usually on the basis of morphological characters.


    Used of offspring or species that show a marked delay in the attainment of independent self maintenance. (cf precocial).



    The daily, seasonal or lifetime geographic range of an organism.



    Interaction of species populations in which one population is inhibited whilst the other population is unaffected by the interaction (cf commensalism, competition, mutualism,

    neutralism, parasitism, predation, and protocooperation). Classic example: an elephant stepping on the nest of a ground-dwelling bird. Better example: trophic group amensalism as in bioturbation effects inhibiting settlement of benthic suspension feeders.



    Referring to a lake that has no overturn whatever because it is perennially frozen.



    Prefix meaning both, as in amphi-American, species or higher taxa occurring in both the eastern Pacific and western Atlantic, ie both sides of the American land mass.



    See antitropical.



    Animals that spawn in freshwater but spend most of their lives in seawater, eg

    salmon (Oncorhynchus, Salmo).



    (1) Referring to evolutionary advance (cf grade).

    (2) Any evolutionary change along a single, unbranching lineage (cf cladogenesis).


     Glossary of biogeographic terms



    Describes a feature or character state in two taxa which can be functionally similar or virtually identical (at least superficially) but which cannot be traced back to the same feature or character state in any common ancestor. Analogous features commonly derive from convergence or homoplasy (cf homologous). The feature or character state itself is termed an analogy.

ancestral character state

    estado de carácter ancestral

    Phylogeny: the known or presumed primitive state (qv) characteristic of the sister outgroup

    (qv) to the group of interest, (cf plesiomorphous).



    (1) Statistics: Abnormal feature or characteristic, departing from mean or expected value. (2) Oceanography: Departure from mean state. Various kinds of anomalies are widely used in oceanographic or geophysical measurements, eg magnetic anomalies are measurable additions

    to or subtractions from the expected local magnetic field due to "fossil magnetic effects" related to polarization reversals of the earth's field. These effects helped demonstrate seafloor spreading.



    The absence of free diatomic oxygen, O. As used in the pelagic literature, also 2

    applies to large hypoxic (qv) water masses in which free oxygen may be at or below

    the threshold of field detectability but in which hydrogen sulfide is not detectably present (eg Eastern Pacific, Arabian Sea).



    Zone of the Antarctic (Southern) Ocean and the continent of Antarctica, including the subantarctic and south Subtropical Convergence (qv); extending from the 0S, the approximate limit of northward ice drift. continental margin northward to about 40



    Referring to an area of above average pressure (high pressure cell) in the ocean or atmosphere, characterized by generalized downwelling within the central region of the cell. The circulation pattern is such that when visualized from above, motion of a particle on the right side is southward in the Northern Hemisphere (clockwise) and northward in the Southern Hemisphere (cf cyclonic, gyre).

antitrade wind

    viento antialisio

    Upper altitude wind in low latitudes that flows counter (poleward) to the lower altitude trade wind (qv).

antitropical species

    especie antitropical


     Glossary of biogeographic terms

    Species occurring in the north and/or south subtropical and/or temperate zones but absent in the intervening tropical (equatorial zone). Biantitropical (or amphitropical) is used to describe this condition for the same species in both hemispheres.

aphotic zone

    zona afótica

    The depths of the ocean in which there is no sunlight, in which the only light present is produced by bioluminescent organisms.



    Phylogeny: Evolutionarily advanced (derived) character state. Applied to features shared by a group of organisms that distinguish these organisms from others. The term means "new featured" (cf derivative).



    Pertaining to the benthic environment and benthos of the continental slope between 65 and

    1050m; the upper part of the abyssal zone.



    A group of islands.

Arctic Ocean

    Océano Artico

    Smallest and shallowest (mean depth = 1,205 m) of the world's five main ocean basins. Area = 2. The shallowness is related to the extreme width of the surrounding 14,090,000 km

    continental shelves, up to 1,700 km wide. Covered by floating pack ice, up to 3 to 4 m thick, over much of its surface.

area cladogram

    cladograma de área

    A cladogram (qv) in which area names are substituted for species names (cf OTU). Steps in

    construction: (1) erect cladogram, (2) determine distribution of component OTU's, (3) substitute the names of areas occupied by those OTU's into the cladogram, (4) find the most parsimonious set of events accounting for the correspondence (and differences) between the phylogenetic and geographic cladograms.



    Living in sand; psammic.


    círculo de especies

    A group of closely related species distributed as a partially overlapping mosaic within a geographic area.


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