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Flashcards in Freshwater Fish (lecture 2) Deck (25):
1

freshwater fish

occupy freshwater habitat for a significant part of lofe cycle

2

freshwater evolutionary perspective

only four fish follow it (lungfish, north and south saratoga, and salamanderfish)
-all evolved in freshwater

3

Gwandan relic(only live in freshwater)

lungfish, saratoga, and salamander

4

Marine colonizer(marine ancestors)

catfish, eel, rainbowfish, galaxiids, blackfish, lampreys, and murray cod

5

reason for few Australian species

-fish need water(Australia is highly variable and pretty dry and arid)
-runoff (low runoff since Australia is 80% arid)
-not looking hard enough
(neglected group of Australia wildlife)
-not looking in the right places (KImbley region have found incredibly new species, but not visited)

6

types of habitats

torresian, eyrean, bassium

7

torresian

-monsoonal, warm
-north coast
-wet/dry season
-wide flood plain

8

eyrean

-arid, ephemeral bodies water bodies
-inland
-source on West of Great Divide
-fluctuating, unpredictable levels
-warm, slow and turbid
-massive floodplain
-salt lakes

9

bassium

-high rainfall, cooler, permanent water
-east coast
-source on East of Great Divide
-fall rapidly to the sea
-clear and cool
-relatively stable flow
-mountain lakes

10

Australia's hydrologic background (time series of flow)

gauged streams
-nationally-80% of stream do not flow continuously over time
-victoria-50%

much greater percentage in ungauged catchments

high inter-annual variability in duration of zero flows

challenging environment for fish to persist in

many exploit refuges

11

Australia's specie richness of freshwater fish compared to the rest of the world

-low
-206 exclusively freshwater native species
-about 70% endemic, especially in Tasmania, south-west WA and the Kimberly region
-71 non freshwater dependent species
-26 exotic or introduced species

12

migration patterns during life cycle

diadromous
-anadromous, catadromous,
amphidromous

obligate freshwater
-potamodromous

13

diadromous

-using two different habitats
-fresh and salt water

14

anadromous

-type of diadromous
-sea to stream
-spends adult life in marine then move to freshwater to spawn
-ex.
lampreys, Tas whitebait

15

catadromous

-type of diadromous
-stream to sea
-spend adult life in freshwater then moves to marine to spawn
-ex.
eel, barramundi

16

amphidromous

-type of diadromous
-non-breeding migration, both ways
-dont move to spawn, but move to take on new food source
-ex.
Australian bass

17

potamodromous

-type of obligate
-freshwater migration
-dont experience environment stress from salt to freshwater
-move during spawn
-ex.
silver perch

18

threatening procesess

habitat change and introduction of exotic species

19

habitat change

-river regulation
-salinisation, pollution, and eutrophication

20

river regulation

a habitat change

dams
-Australia has variable rainfall
-used for human

consumptions
barriers from moving to freshwater
-lead to fragment
population (higher chance of extinction)

prohibits the nutrients for down stream food chains

alter flow regimes

high flows occur in the summer instead of the environmental spring due to dams
-effects fish spawn

cutting down brush
-bringing more salt to the surface
-loss of habitat

21

salinisation, pollution and eutrophication

-a habitat change

-95% of Australia's original wetlands degraded or lost due to rural development and mining

-particularly severe in heavily populated coastal areas and farming areas

-salinisation is caused by land clearing resulting in a rise of the salt-laden water table

-agricultural chemicals

22

introduced or exotic species

trout, mosquito fish, and carp

23

trout

-introduce specie
-introduce for angling to feel like the old country
-preservation of trout fishery is strong
-predators of native fish

24

mosquito fish

-introduce specie
-used for mosquito control but failed
-competes with natives

25

carp

-accidental
-number one pest
-impact debated
-bottom feeder
-destructs habitat beds
-shear biomass