Glossary: B

Batesian mimic

a form of mimicry in which a harmless species evolves to resemble one or several harmful species. The harmless species is then protected from predation by resembling the harmful species.


A horny substance, commonly known as whalebone, that grows as plates from the upper jaws of certain whales, and forms a fringelike filter for extracting plankton such as krill from seawater.


A barrier, such as a low earth dam, which impounds water for irrigation.

basal metabolic rate

the minimum number of kilocalories a resting animal requires to sustain basic physiological processes.

benign introduction

An attempt to establish a species, for the purpose of conservation, outside its recorded distribution, but within an appropriate habitat and eco-geographical area.


Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

beta diversity

See diversity - beta.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


helps break down and decompose dead plants and/or animals


the ability of some living organisms to produce light and the emission of this biologically produced light.


A measure of the abundance of an animal in term of the mass (weight) of the animals, stated as either the total mass of the animals in a given location or per unit area.


A major habitat category, based on distinct plant assemblages which depend on particular temperature and rainfall patterns. E.g. tundra, temperate forest and rainforest, etc. The biomes we use are described in: Campbell, N. A. 1993. Biology. 3rd Edition. Benjamin/Cummings Publ. Co., and Raven, P. H., and G. B. Johnson. 1992. Biology. 3rd Edition. Mosby-Year Book, Inc.


Something that is alive, or used to be alive.


having two margins which are toothed, like a comb.


Referring to animal that walks on two legs.


a type of appendage characteristic of members of the arthropod group, Crustacea. The appendage branches from a basal portion, the protopodite, into two distal branches, the endopodite and the exopodite. Each of these branches might be made up of multiple segments. There are many variations on these appendages and their functions. Compare to uniramous.

blastopore forms anus

Blastopore: external opening of the archenteron in the gastrula during development.


The opening of the nostril(s) of a whale, located on the top of it's head, through which the whale breathes and from which the spout is produced.


A layer of fat beneath the skin.


a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.


Referring to northern regions. Specifically, the region south of the Arctic Circle and north of latitude 50 deg. N; the term may also refer to an area dominated by coniferous forest.


a member of the mammalian family Bovidae, within the order Artiodactyla. This family includes cows, bison, buffalo, antelopes, gazelles, sheep, goats, muskoxen, and many others.


1.In brachiopods (Phylum Brachiopoda), a pair of feathery structures forming part of the lophophore, they are used in food collecting. 2. In crinoids (Phylum Echinodermata, Class Crinoidea), the long, plated, flexible arms containing a water vessel, from which the tube feet arise. When feeding the tube feet are extended, at other times they are covered by brachial plates. Smaller arms coming from the main brachia are called pinnules and are made up of pinnular plates. Singular: brachium.


To move around in trees by arm-swinging from branch to branch.

brackish water

areas with salty water, usually in coastal marshes and estuaries.


Leaping from the water surface (usually by whales).

breeding season

the time of the year during which mating occurs.


Having inconspicuous dark streaks or flecks on a gray or tawny background.


One of a family of American epiphytic herbaceous plants including the pineapple and Spanish moss.


noun: the offspring of a single birth or set of eggs, or any group of young that is being cared for together by an adult.

verb: to incubate eggs.

brood parasite

lays eggs in the nests of another animal, of the same or different species, who then provides parental care to the offspring


An herbivore that feeds on shoots and leaves of trees and/or shrubs, as opposed to grasses (compare grazer).


relating to the mouth or oral cavity.


a sac-like space made up of fibrous tissue and containing a thick, lubricating fluid (synovial fluid). Bursae (plural) are found in areas of vertebrate bodies where friction between skin, muscle, ligaments, or bones might occur. They help to reduce this friction.


Fish taken in a fishery which are not of the species intended for harvest.


Bundle of strong threads used to attach the animal (adult mussels and many larval bivalves) to the substratum. Synapomorphy of the Bivalvia.