Fish Flashcards
FM01
these are fish that adapt over a wide range of temperatures
Eurythermic
these are fis hthat tolerate a narrow range of temperatures;
most marine fish
Stenothermic
what happens to the amount of dissolved oxygen and toxicity of ammonia in water when the temperature is increased?
- reduces amount of dissolved oxygen
- increases toxicity of ammonia
what is the salinity of fresh water?
0.5 ppt
what is the approximate salinity of sea water
~35 ppt
this is the ratio of the weight of the water sample to distilled water at 4 degrees C
specific gravity
what pH range can the majority of pet fish be kept at?
6-8
what might high water pH indicate?
elevated levels of ammonia
what 3 things will the toxicity of chlorine/chloramine in water depend on
- pH (low)
- temperature (high)
- dissolved oxygen (low)
chlorine or chloramine?
unstable;
leave in an open container for 24h
chlorine
chlorine or chloramine?
stable;
addition of compounds or carbon filter (chemical filter) in order to be removed
chloramine
name the nitrogenous compound that can be in the fish tank
metabolic waste product;
primary end product of protein catabolism;
excreted via gills and kidneys;
toxic;
levels should be kept at 0mg/L
ammonia
name 4 causes of elevated ammonia in a fish tank
- overcrowding
- immature or damaged biological filter
- excessive food
- decomposed plant material
name 3 types of filters for fish tanks
- biological
- mechanical
- chemical
name the type of fish tank filter
effective against nitrifying bacteria and nitrogenous waste;
sensitive to antibiotics and stocking densities;
takes time to establish
biological filter
name the type of fish tank filter
removes debris like sand and floss
mechanical
name the type of fish tank filter
removes dissolved organic compounds
chemical filter
name the type of chemical filter for a fish tank
removes chloramine
carbon filter
name the type of chemical filter for a fish tank
reduces nitrogenous waste
ozone
name the type of chemical filter for a fish tank
disinfection
UV
this improves gas exchange in a fish tank by increasing the water surface area through aeration
air pump
what is the minimum size of a fish tank
30x30x45 cm
36 L of water
how should a fish be transported?
(3 things)
- plastic bag with water from tank
- cover with opaque wrapping
- polystyrene container for isolation
how much water is needed in the bag for transport of a fish
1L per cm of fish
name 5 parts of the fish physical appearance that should be assessed to determine health status
- eyes
- fin and skin condition
- mucus production
- spinal deformities
- distended abdomen
name 2 abnormal eye conditions a sick fish might show on physical appearance
- cloudy
- bulging (exophthalmia)
name 4 abnormal fin and skin conditions a sick fish might show on physical appearance
- discolouration
- growths/swellings
- ulcers
- fungal infection
name 3 measurable clinical signs that can be assessed in fish
- food consumption
- respiratory rate (operculum movement)
- posture in water column
name 3 behaviours that can be observed in a hyperactive fish
- erratic swimming
- rubbing
- jumping
what method is used to anaesthetise fish
add anaesthetic agent to the water
(‘inhalation anaesthetic’)
name 3 anaesthetic agents used for fish
- MS222 (tricaine methane sulphate)
- 2-phenoxyethanol (Aqua-sed)
- Clove oil/Eugenol/Isoeugenol (Aqui-S)
name 2 ways to test the depth of anaesthesia in a fish
- ataxia
- loss of righting reflex and response to stimuli (squeeze base of tail)
how to monitor the resp rate of a fish?
observe movements of operculum
name the level of anaesthesia in a fish
normal swimming behaviour ad reaction to external stimuli
level 0;
normal
name the level of anaesthesia in a fish
still swimming but reduced reaction to external stimuli;
equilibrium normal;
normal opercular rate
level 1;
light sedation
name the level of anaesthesia in a fish
no swimming;
loss of equilibrium (rolls over, belly up) but may still try to right itself;
normal to slightly decreased opercular rate;
still maintains a tail reaction
level 2
deep sedation/light anaesthesia
name the level of anaesthesia in a fish
complete loss of equilibrium;
complete loss of reactivity (negative tail reaction);
very slow opercular rate;
slow heart rate
level 3
surgical anaesthesia
name the level of anaesthesia in a fish
total loss of opercular movement followed by cardiac arrest;
EUTHANASIA STAGE
level 4
medullary collapse
name 3 ways to take a skin sample of fish
- impression smear
- biopsy
- skin scrape
name the common fish disease
protozoan ectoparasite dinoflagellate;
imbeds in the gills, skin and fins;
causes discomfot to the fish and reduced feeding;
Tx: immersion in salt baths
Freshwater Velvet Disease
(Piscinodinium pillulare)
name the common fish disease
a ciliate;
penetrates the host’s skin creating a white spot;
leads to secondary bacterial infection;
free swimmin stages of the parasites are susceptible to Tx;
lifecycle is 3-7d at 24-26C);
Tx: formalin or salt
White Spot or Ich
(Ichthyophthirius multifiliis)
name the common fish disease
asymptomatic in fish;
can manifest itself as localised non-healing ulcers or internal granulomas;
range of non-specific clinical signs may be noted such as emaciation and anorexia;
confirm via PCR, ZN stains or culture;
ZOONOTIC
Mycobacterium
name the 2 main species of Mycobacterium that affect fish
M. marinum & M. fortuitum
name the common fish disease
frequently encountered gram neg bacterium;
affinity for gills, skin and fins;
erosive/necrotic lesions (whitish plaque with reddish periphery);
may lead to systemic disease;
Tx: controlled water temp reduction and Bactericides (oxytet)
Columnaris disease, saddleback, cotton wool disease
(Flavobacterium columnare)
name 3 risk factors for Columnaris disease, saddleback, cotton wool disease
- physical injury
- low oxygen
- high nitrite
name the common fish disease
most common water mould disease in fresh water fish;
primarily secondary invader;
invades epidermal tissue usually around head or fins with white cotton wool-like appearance
Saprolegnia (Oomycota)
name 3 predisposing factors for Saprolegnia (Oomycota) in fish
- wounds
- stress
- fall in water temp
how should fish be euthanised?
anaesthetic overdose followed by destruction of the CNS (pithing)
