Lecture 23 Flashcards
What are the two classifications of jawed fish?
bony fish (teleosts) cartilaginous fish (elasmobranchs)
Do all fish require water to breed?
yes
What are two examples of fish which change sex in response to social change?
anemonefish
swordfish
What are two examples of fish which keep their temperature above ambient temperature?
tuna
white shark
What is the term for temperature being dependent on the environment?
poikilotherms
Can most fish be described as herbivores, omnivores or carnivores?
carnivores
Are most fish neutrally buoyant or negatively buoyant?
neutrally buoyant
What are four ways fish can swim?
vertically
on their side
inverted
in relation to the surface
What is a Demersal species?
a species which lives in relation to an edge e.g. top/wall/bottom
What is a Pelagic species?
an Oceanic species
What is the predominant determinant of fish health?
water quality
What are four features of water which is extremely important?
pH
hardness
expected chemicals
unexpected chemicals
What are three examples of ‘expected chemicals’ found in water?
ammonia
nitrites
nitrates
What happens to the partial pressure of oxygen when water temperature increases?
partial pressure of oxygen decreases
What can rapid temperature change cause?
buoyancy
Where is there the highest concentration of oxygen in a fish tank?
at air-water interfaces
What disease can super saturation of nitrogen lead to?
gas bubble disease
How can water movement lead to increased oxygen requirement in the water?
it can disturb sediment leading to increased decomposition of detritus
What can stress lead to?
opportunistic infections
What is a commensual of fish?
Aeromonas hydrophila
What behaviour can fish show which are kept alone?
stereotypic behaviour
What effect can increasing stocking density have on bullying?
decreases it
What is ‘upside down goldfish’ usually caused by?
taking in gas
Do ornamental lakes have filtration system?
no
In what kind of housing are Koi fish often kept?
display ponds
What problem does breeding traps avoid?
parental cannibalism
What should transportation of fish involve?
double bagging in thick polythene bags in a rigid container
What characteristic of gravel makes under gravel filtration a problem?
if the gravel is too fine
What does UV filter assistance do?
stops algal bloom
Is visual examination of water a good way to inspect water quality?
no
What fish behaviour may suggest poor water quality?
gasping
What are two things found in tap water which may be a problem for fish?
chloring
antiparasitics
What is the problem with live plants in fish tanks?
they often die back and cause increased biological oxygen demand
What is flaked fish food often lacking in?
roughage
What is a problem with ponds being too shallow?
does not give enough space for overwintering fish to avoid the ice when the pond freezes over
Why are larger ponds better than small ponds with regards to heat?
better thermal buffering capacity
How can water depth affect reproduction?
decrease in water depth can trigger spawning
Can fish can sunburn?
yes
Why should fish tanks be placed out of direct sunlight?
because it encourages agal growth
What is the problem with mixing fish and non-fish?
if the non-fish die they can reduce the oxygen in the tank
How can tap water be treated to reduce the chlorine?
leaving the tap water overnight
What substance in the tank causes new tank disease?
nitrites
What should the level of nitrites in tank water be?
zero
What kind of water makes testing for nitrites less effective?
hard water
