Fish

Question 1

What are the 4 types of fish?

Answer 1

• Cartilaginous fish
• Bony fish
• Jawless fish
• Lungfish

Question 2

What are the 4 ways in which fish are kept?

Answer 2

• Pet fish
• Aquaria
• Farmed
• Laboratory

Question 3

Label the following:

Answer 3

Question 4

What is the purple line showing on this image?

Answer 4

The lateral line - sensory system that stetects the pressure of the water allowing the fish to detect other fish, predators and how deep they are in the body of water

Question 5

What is found under the scales and what is it’s purpose?

Answer 5

Skin - osmotic barrier, produces a mucous layer hat acts as lubrication and as a defence against pathogens

Question 6

Fish do not have a diaphragm or lungs so what is the name given to the body cavity?

Answer 6

Coelom

Question 7

What is the name given to fish because their body temperature is the same as the temperature of the water?

Answer 7

Ectotherms

Question 8

What is the function of a swim bladder and what is the difference that can be found?

Answer 8

Maintain bouncy
2 kinds depending on fish, on is a gas gland that allows gas in and out of blood and the other is attached to the GI system

Question 9

What has a longer GI tract on fish, carnivore’s or herbivores and why?

Answer 9

Herbivores longer - allows digestion + absorption of vegetable material as less nutrient dense

Carnivores shorter - for rapid digestion and absorption as dense nutrient and protein diet

Question 10

How can the liver and pancreas be found in fish?

Answer 10

They can be found combined

Question 11

What is the largest organ in fish and which is the most powerful?

Answer 11

Largest = liver
Powerful = kidney (can have 1 or 2)

Question 12

How many changers does the fish heart have and what are their names?

Answer 12

4 - run in sequence
venous sinus - atrium - ventricle - bulbous arteriosus

Question 13

What is the primary function of gills in fish and what structures allow this?

Answer 13

Gas exchange - water passes in mouth and out through gills

Rakers prevent damage from debris
Arches hold the gills in position
Filaments and lamellae create large surface area for oxygen absorption

Question 14

What is an extra function that gills have?

Answer 14

Assist in excretion of nitrogenous waste

Question 15

Water doesn’t contain much oxygen, how do fish optimise their oxygen absorption?

Answer 15

Blood flows in a counter current system to oxygen

Question 16

Match to fish to the description:

Salt water
Fresh water

Body has higher salt concentration than surrounding water
Body has lower salt concentration than surrounding water

Answer 16

Salt water - Body has lower salt concentration than surrounding water
Fresh water - Body has higher salt concentration than surrounding water

Question 17

What does most of a fish energy go towards?

Answer 17

Maintaining bodily fluid levels as more salt outside the body mans it tries to come into the body and vice versa

(so salt water fish excrete a lot of salt and hardly pee, fresh water fish pee a lot and maintain as much salt as possible)

Question 18

What organs are involved in osmoregulation in fish?

Answer 18

Kidney, gills and GI tract

Question 19

What are the 6 main components that contribute towards good water quality?

Answer 19

1. Ammonia and nitrate
2. Oxygenation and CO2
3. Chemically clean water
4. Water hardness, salinity, pH, temperature
5. Low levels of organic pollution
6. Stability not fluctuation

Question 20

Is clear water a sign of good quality?

Answer 20

No

Question 21

What issues do ammonia and nitrate pose to fish?

How can their levels be monitored?

What causes these rises in levels?

How can a rise in levels be prevented?

Answer 21

Cause stress for fish and physical damage to their tissues (bright red gills = ammonia pollution)

Not detectable so cannot be monitored

Constant pollution from fish, food and live plants

Biological filtration with good bacteria, sterilisation of surfaces (careful of good bacteria!!)

Question 22

What promotes oxygen circulation in water?

What can be added to help with oxygen levels?

What changes oxygen levels in ponds throughout the day?

What does high oxygen mean vs low?

Answer 22

Water movement that disturbs the surface

Air stones and mechanical filters

Temperature

high O2 means low CO2 levels and vice versa

Question 23

What are chemicals that pose a threat to the water quality?

What can be done to keep the water as chemically free as possible?

Why should vets be aware of the measures taken to reduce chemicals in the tank?

Answer 23

Pesticides, chlorine from the tap (gill tissue necrosis), heavy metals ie. copper in tank treatments, organophosphates

Chemical filtration - black sponge - charcoal - can absorb and detoxify water

Medicine given to fish is chemicals so must make sure the fish will actually receive medication and that the filters aren’t removing it

Question 24

Why should you be aware of water hardness, salinity, pH and temperature?

What temperature do goldfish like compared to tropical and marine?

Answer 24

Different species have different requirements and often narrow limits
All fish in the tank should be similar
Goldfish 16-20ºC
Tropical and marine 27ºC

Question 25

Why is organic pollution a risk to fish?

Answer 25

Ammonia can easily build up and.. .. creates ideal conditions for: Pests Parasites Disease Fungus Opportunistic bacteria

Question 26

What causes organic pollution in fish tanks?

Answer 26

decomposing faeces, uneaten food, algae, other detritus (often hidden in substrate so people don't notice)

Question 27

What does 'stability not fluctuation' mean in reference to water. quality?

Answer 27

Ensuring that pH, temperature and other parameters remain as close to a constant as possible Changes cause stress as the fish are constantly trying to adapt to the new environments which is not normal in the natural environment

Question 28

Explain the nitrogen cycle:

Answer 28

NH3 (ammonia) and NH4 (ammonium) produced by decaying food and plant matter, fish faeces and dead fish Both converted into less toxic NO2 (nitrite) by Nitrosomonas bacteria Converted into safer NO3 (nitrate) by Nitrobacter bacteria Nitrates can be taken up by plants and removed by water changes during clean out REMEMBER - nitrate is GREAT nitrite is SHITE!!

Question 29

What causes brown blood disease in fish?

Answer 29

Ammonia

Question 30

Table the components of a good tank set up?

Answer 30

Question 31

Some tanks have UV sterilisers, how do these work?

Answer 31

Bulb in casing outside of tank and water passed through and the UV kills any pathogens in the water

Question 32

What are corals? Why is it important to have an understanding of them?

Answer 32

Symbiotic species, photosynthesise, rely on bacteria that live in them Very sensitive to changes in water so die very easily and very expensive

Question 33

Why should your sponge filters not be washed under the tap?

Answer 33

Kills all the good bacteria triggering new tank syndrome even if there was a well established environment

Question 34

What is new tank syndrome?

Answer 34

Ammonia spikes to high rapidly and fish dead overnight

Question 34

What does overstocking the fish tank cause?

Answer 34

Overloads the biofilter leading to ammonia build up and therefore new tank syndrome

Question 35

What should be considered when creating a community?

Answer 35

- water parameters and habitat requirements - schooling or solo - swimming levels - compatibility - predators - aggression and intimidation

Question 36

What type of feeder are fish? What are the 3 types of feeders? What is a common disease in fish caused by overfeeding?

Answer 36

Opportunistic Surface, mid-range and bottom (see image) Fatty liver disease - fatal

Question 37

Why are blue-green and red algae blooms problematic and why do they start growing?

Answer 37

Thrive off of nitrates and phosphates Contribute to low oxygen levels

Question 38

Why can fungus pose a threat to fish?

Answer 38

Can become opportunistic and grow on the fish

Question 39

What type of feed is usually given to omnivores? carnivores? herbivores?

Answer 39

Can have a varied diet of formulated food (pellets etc.), fresh food, live food and frozen food Prefer live prey (invertebrates) that they can hunt (risk of disease or parasites), frozen cubes, freeze dried invertebrates Graze aquarium plants, fresh veg., algae/seaweed tablets

Question 40

What diets are farmed fish usually on? What diets are most public aquaria on?

Answer 40

High proteins and lipid prepared pellets for optimal breeding (for salmon and then given to other species) Wet fish diets, usually human standard chunks of fish but always risk of disease or parasite

Question 41

What are the standard procedures when looking at fish as a vet?

Answer 41

- take history - observe community - test water quality - check rest of environmental husbandry (diet, stocking, lighting, biofilter)

Question 42

What does a phosphorus deficiency cause in fish?

Answer 42

Causes their jaw to become stuck open

Question 43

What are some key behavioural changes and concerns in fish?

Answer 43

- circling - bottom-sitting (all in tank will be) - drifting - hovering without response to stimuli - head-standing - tail-walking - flashing (itchy) - piping or gasping - colour changes

Question 44

What are some physical signs of illness in fish?

Answer 44

Fin rot Fungud Ulcers Cloudy eyes Inflamed gills Egg bound

Question 45

What are some diagnostic tests that can be done on fish?

Answer 45

Skin scrapes - not scale removal and be careful of mucous layer - move slide cranial-caudal along scales gently Gill clips - tiny clip as highly vascularised - lift operculum to access gill tissue Fin clips - again a tiny clip all for histology

Question 46

When would you need to use imaging with fish?

Answer 46

Radiography (should use GA) - abnormal shape - abnormal swimming - buoyancy disorder - suspected blockage or foreign object Ultrasound (can be done in water so no gel required) - suspected tumour - sexing

Question 47

Where can you take a blood sample in fish? What can be investigated?

Answer 47

Tail vein (ventral to spine at 90º angel) Cardiac puncture in dead fish Oxygen transport capacity, immune potential, stress levels, disease, chemical intoxication, nutritional status, cellular abnormalities

Question 48

When should fish be sedated? How should the fish be prepared? What should be done if sedation is more than a few minutes? How is it given and reversed?

Answer 48

Before handling or stressful procedures 12-24hr starvation period to prevent regurgitation into gill tissue and to limit nitrogen waste excretion Gil ventilation to keep them under (sedation in water) and oxygenated Dissolved in water fish is in and revered by placing fish in water without it