Glossary

97 terms beginning with B · showing 41–80

1. bioball

   Type of biological filter medium consisting of a plastic ball designed in such a way that the available surface area for bacterial colonisation is maximised. The precise form differs depending on manufacturer.

2. biocenose

   A group of organisms forming a self-sufficient ecological community in a particular habitat.

3. biochemistry

   The chemical composition of an organism, living system or biological entity; the study of chemical substances and processes occurring within living organisms.

4. biocide

   A chemical agent that is toxic or lethal to living organisms.

5. biodiversity

   The number, variety, and genetic variation of organisms found within a specified geographic region, both within and between species and ecosystems. Often used as a measure of overall ecosystem health.

   Used in 16 profiles

6. bioerosion

   Erosion of oceanic or terrestrial substrates by living organisms.

7. biofilm

   Aggregate of microorganisms adhering to one another and forming a complex, carpeting structure on living or non-living solid surfaces. Often associated with surfaces that are submerged or regularly in contact with water.

   Used in 146 profiles

8. biofilter

   Pollution control technique employing living matter to capture and biologically degrade potential pollutants. Aquarium biofilters tend to contain a medium with a large specific surface area (SSA) favouring colonisation by billions of beneficial microorganisms.

   Used in 6 profiles

9. biogeography

   Study of the geographic distribution of plants, animals and ecosystems in both space and geological time.

   Used in 13 profiles

10. biological filtration

    See biofilter.

11. 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.

12. bioluminescence

    Emission of visible light by living organisms including certain fishes.

13. biomass

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

14. biome

    A major regional or global biotic community normally characterised by the dominant vegetation and local climatic conditions, e.g., deserts, tropical rainforests, tundra. The two major aquatic biomes are freshwater and marine but these are often broken down into less-generalised categories.

15. biometrics

    Statistical study of biological data and phenomena.

16. bioregion

    A biological region defined by characteristics of the natural environment rather than by man-made divisions and tending to contain distinctive flora, fauna and ecosystems. Also known as 'ecoregion'.

17. biota

    The living organisms inhabiting a given region.

18. biotic

    Consisiting of, associated with or derived from living organisms. Biotic factors in an environment include the organisms themselves plus predation, competition and other interrelationships.

19. 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

20. biotope aquarium

    Arguably misapplied term used fashionably when describing an aquarium set up to resemble the natural habitat of specific fish(es) including replication of water chemistry, vegetation and sympatric fish species.

    Used in 17 profiles

21. bivalve

    A mollusc belonging to the class Bivalvia which includes clams, oysters, mussels, scallops, etc.. Members are characterised by possessing a shell comprising two hinged valves.

    Used in 6 profiles

22. blackwater

    In ichthyological and aquarium literature typically refers to water rich in humic acids and poor in nutrients such as that associated with ancient peat swamps or parts of the Amazon river drainage, and thus differs from clearwater and whitewater. Fish species inhabiting such environments typically require similar conditions in captivity, especially if wild caught.

    Used in 169 profiles

23. bloodworm

    The freshwater larvae of certain midges which appear bright red due to their high haemoglobin content. Some species of the non-biting Chironomidae family are produced commerically for fish food with the larvae frozen or freeze-dried.

    Used in 1,068 profiles

24. bloom

    A population explosion of phytoplankton such as algae.

    Used in 16 profiles

25. blue-green algae

    See 'cyanobacteria'.

26. body depth

    The vertical distance between the dorsal and ventral margins of the body measured at the base of the pectoral fin where it joins the body. In most icthyological works the greatest dimension, normally anterior to the dorsal fin, is taken but in some cases body depth is measured at the origin of pectoral, pelvic and first anal. Fins or fin bases are not included in the measurement, however.

    Used in 85 profiles

27. bogwood

    Non-petrified wood that has been preserved in a peat bog, often used as decoration in aquaria.

    Used in 114 profiles

28. bony fishes

    See Osteichthyes.

29. boulder

    A rock with grain size in excess of 256 mm diameter.

    Used in 370 profiles

30. brackish

    Refers to water with a salinity between that of freshwater and seawater, technically 0.5 - 30 grams of salt per litre, equivalent to 0.5 - 30 parts per thousand (ppt).

    Used in 114 profiles

31. branched rays

    A soft or segmented fin ray which is distally forked/divided into two.

    Used in 51 profiles

32. branchial

    Relating to, of, or resembling the gills of a fish.

    Used in 5 profiles

33. branchial arch

    One of the bony or cartilaginous arches situated on either side of the pharynx that form the support for the gills.

    Used in 2 profiles

34. branchial cavity

    Cavity located inside the mouth and enclosing the gills; also known as 'gill cavity'.

35. branchiostegal membrane

    The membrane, sometimes referred to as the gill membrane, connecting the branchiostegal rays and enclosing the ventral portion of the branchial cavity. Normally extended when the opercle of a fish is open, sealing the branchial cavity and creating a vacuum in the mouth, and also used during threat, courtship and other communicative behaviours in many species.

    Used in 5 profiles

36. branchiostegal ray

    One of the dermal, bony (sometimes cartilaginous), bilaterally paired, flattened struts inserting on the epihyal and/or ceratohyal (sometimes the interhyal and hypohyal) that supports the branchiostegal membranes.

    Used in 4 profiles

37. breeding cycle

    In fishes, the period of time between hatching and first spawning within a particular generataion.

    Used in 3 profiles

38. breeding line

    A group of identical, pure-breeding diploid or polyploid organisms, distinguished from others of the same species by a unique phenotype and genotype. Important in production of line breeding ornamental fish strains.

39. breeding stock

    Fishes raised and stocked for captive breeding.

    Used in 1 profile

40. breeding trap

    Net or plastic container suspended or floated in an aquarium and used to isolate gravid female livebearers or fry collected from the main aquarium. Available in a number of designs, with plastic ones generally containing two compartments separated by a grille or opening large enough that fry, but not adults, can pass through.