Biodiversity

Threatened species

The Action Plan for Australian freshwater fishes

R. Wager and P. Jackson
Environment Australia, June 1993
ISBN 0 6421 6818 0

Glossary

aestivation
inactivity or dormancy during drought periods.
anadromous
refers to fishes which migrate from salt water to fresh water to spawn.
bioaccumulation
the accumulation of chemicals through the food chain by living organisms.
brackish
slightly salty.
catadromous
refers to fishes that migrate from fresh water to estuarine or salt water to spawn.
channelisation
artificial modification of a watercourse to ensure maximum flow and minimise flooding.
conspecific
belonging to the same species.
congeneric
belonging to the same genus.
demersal
refers to fish eggs which are neutrally or negatively buoyant and sink to the substrate.
de-snagging
removing logs or branches from a watercourse.
detritus
material from decomposing plants and animals.
diadromous
refers to fishes that migrate between fresh water and marine environments in either direction.
emergent
protruding above the water surface (eg emergent vegetation).
endemic
native or restricted to a particular geographic area.
eutrophication
the enrichment of waterbodies with nutrients, often leading to excessive plant growth and oxygen depletion.
exotic
refers to an organism from another zoogeographic region; usually applied to species from another country or continent
fingerling
refers to a young individual fish of a large species when it is about the size of a finger.
fish way
a structure allowing fish passage around an artificial barrier in a stream (eg fish ladders).
flow regime
the prevailing water flow pattern of a stream.
fry
newly hatched larvae which have used their yolk and are actively feeding.
impoundment
general term for any confined water body, usually due to artificial structures but may be natural.
instream habitat
specific place in a stream where an animal lives (usually submerged).
introduction
(of an organism) the intentional or accidental dispersal by human agency of a living organism outside its historically known range.
larva
newly hatched fish in which the yolk sac is still present (plural – larvae, adjective – larval).
lentic
refers to standing or still waters such as lakes.
lotic
refers to flowing waters such as rivers.
native
refers to an organism that naturally occurs in Australia.
noxious
dangerous or harmful as a pest.
pelagic
refers to fishes which inhabit open waters or near the surface, or to eggs or larvae which occur in these areas; pelagic eggs are buoyant or semi buoyant.
pH
a measure of acidity or alkalinity.
plankton
small animals (zooplankton) and plants (phytoplankton) which mainly float or drift near the surface of rivers, lakes or the sea.
planktivorous
describes a fish that eats plankton.
recruitment
the process of adding to the population or increasing the total numbers of a fish species.
regulated streams
streams in which the natural flow of water is artificially controlled or modified (through impoundments, locks or hydro-electricity schemes).
Re-introduction
(of an organism) the intentional movement of an organism into a part of its native range from which it has disappeared or become extirpated in historic times as a result of human activities or natural catastrophe.
Re-stocking
the movement of numbers of plants or animals of a species with the intention of building up the numbers of individuals of that species in an original habitat.
riparian
pertaining to or on a bank of a lake or river.
salinity
a measure of the amount of dissolved inorganic material in the water. Sea water has a salinity of about 34 (parts per thousand); freshwater has a salinity of less than 3.
school
a group of fishes moving together and behaving in a co-ordinated manner.
siltation
the process in which lighter soil fractions are transported into a waterway and carried downstream to be deposited in low flow or still areas as silt.
snag
logs or branches in a stream.
substrate
the bottom or a firm supporting surface which can act as a site for attachment.
taxon
group of similar animals; usually refers to genus or smaller grouping (plural – taxa).
translocation
the movement of living organisms from one area with free release in another; applies to the movement of species both within and between zoogeographic regions (see introduction, re-introduction and re-stocking).

Before you download

Most publications are available as PDF files. Adobe Acrobat Reader  is required to view PDF files.

If you are unable to access a publication, please contact us to organise a suitable alternative format.

Key

   Links to another web site
   Opens a pop-up window