Fish Husbandry Flashcards
What do fish need from their environment?
Water, Oxygen , Stable conditiosn (Water chemsitry & Temp), Complete balance diet
What can poor husbandry lead to?
Increase stress, Decrease immunity
How do you maintain water quality?
Correct stocking density, Filtration system, Aeration, Monitor Temp, Regular cleaning & partial water changes, Regular water quality testing
What does it take to maintain healthy fish?
Compatible sepcies together, Quarantine new fish for 4 weeks before introduction, Provide good quality food
What are the water quality components you need to be aware of?
Dissolved gases, Nitrogenous compounds, Temo, pH, Hardness, Alkalinity, Salinity + other
List the dissolved gases
Oxygen, Nitrogen, Carbon dixoide
Why might dissolved oxygen fall to fatally hypoxic levels?
Overstocking, overfeeding, lots of rotting organic matter actively degraded by bacteria, too many plants
Where is the main source of dissolved oxygen in most bodies of water?
Photosynthesis by submerged plants but plants require daylight (using up OD) so large decreses in OD may occur during the night if plants are preent
When should you especially measure dissolved oxygen levels?
Early in the monring
What are the oxygen requirements?
Varies with species, age, size & health of fish, Increses with feeding & stress, Most fish require at least 6mg/I dissolved oxygen
Why might there be carbon dioxide in the water?
Produce via respiration by the fish, bacteria and plants at night
When are the dissolved levels of carbon dioxide?
Just before down and in fish who are left in a sealed plastic bag for long periods
What nitrogenous compounds might be present in bodies of water?
Fish excere ammonia (NH₃) from gills + kindets, Bacteria use ammonia as energy source (convert to nitrie NO₂⁻) and Other bacteria convert nitrie into nitrate NO₃²⁻) Ammonia & Nitrite are v. toxic
Can you draw out the nitrogen cycle?
Optimum levels of Ammonia
0mg/l
Optimum levels of nitrite
0ml/l
Optimum levles of nitrate
<50mg/l
How do you prevent “New tank syndrome’?
Several weeks for bacteria to become establoshed & for filter to function efficiently in new tanks/ponds before adding fish
Can you draw out what occurs during new tank syndrome?
What two bacteria are needed to establihs a filter?
Nitrosomonas & Nitrobacter
What Is the process of filter maturation referred to as?
Cycling
What does nitrosomonas do?
Oxidise ammonia to nitrite
What does nitrobacter do?
Oxidise nitraite to nitrate
How can we speed up the process of cycling?
Seed the filter with part mature media from an establihs tank, Use concentrated bacteria, Use hardy “seed fish” (~ethis)
Why must cycling a filter be monitored?
Parameters are monitored to determine when more stoack can be added, Addition of new animals will increase NH₃ = requires more bacteria to grow
After cycling how are nitrate levels controlled?
Via plants + regular water changes
What can excess nitrate lelves cause?
Excessive plant growth/algal blooms
Why is temperature important?
Fish are ectothrmic, Species dependant (all have optimum range but some tolerate wide ranges - goldfish 2-40)
What rates rely on temperautre?
Metabolic, feeding and grwoth
What can rapid changes in temperature cause?
Stress & Reduce resistance to disease
What does increase temperature lead to?
Decrease dissolved oxygen, Increase toxicity of ammonia (NH₄⁺ → NH₃)
What is the optimum pH levels of hobbyists for most fish speices?
06-8pH
What value of changes of pH during acclimitastion is recommnede?
0.3 or less per day
What could be an underlying cause for low pH?
Runoff from peaty soil into pond during heavy rain/due to poor drainage design, Tap water can be mildly acidic due to chlorine (formation of hydrochloric acid)
What could be an underlying cause for high pH?
Runoff from soil/concrete into pond during heavy rain/poor drainage design, Build-up of ammonia if filtration system not working properly/excessive decomposing waste patter present
Sailinity, What’s it about?
Most pet fish in the UK are freshwater, Marine species are much more challenging to keep & Only toleralte narrow ranges of salinity
Describe the simple treatment for freshwater fish
Salt (pure sodium chloride) can be used as a treatment for freshwarer fish at times of stress (transport/disease) dissolved in their water at specifc conc (eg. 2-6g/L)
How could chlorine be present in the water?
Tap water, Toxicity depends on pH, temp, dissolved oxygen and species of fish
How could metal solutes be present in the water?
Copper, Iron, Lead - leach out of metal water pipes
What household substances be present in water?
Pesticides, Aerosal sprays, Tobacco smoke
Describe the ideal freshwater aquarium management
Bigger = Better (Larger water volume → More stable water quality), Posistion away from direct sunlight, draughts & room heaters, Use aquarium heater for tropical fish
Lighting for freshwater aquariums
Artifical preferable to sunlight - controlled, Natural periods - 10-12h per day + Helps with plant growth
Aeration for freshwater aquariums
Filter usually provides sufficient aeration + water circulation in small hobbysit tanks, Additional provided via air pumps + air-stones
What filtration opetions are avilable for freshwater aquiariums?
Foam filter, Undergravel filter, Power filter, Trickle filter
What functions doe a filter carry out?
Mechanical (suspended debris) + Biological (encourage bacterial + micro-organism ammonia + frnitrie) filtration
Average lifespan of goldfish
25 (5-10)
Where would you position a pond?
Open area - Sun for most of the day (shade midday & shelter from winter winds), Away from trees & Overhanging bushes, Ground level (no-run-off), Access to water & electricity
Size of pond
Larger usually better in terms of stable conditions but cathcing fish becomes difficult
Filtration in ponds
Similar principle to those used in aquaria, Different types avilable
Ultraviolet lamps + Ponds
Can be used for large ponds + aquaria, Kill single-cell algae & other micro-organisms in water pumped systems
Pumps + Ponds
Helps with water movement & aeration, Essential if filter used, to keep water flowing through it
Ponds + Winter
At <4℃ cold water floats above warm water & freezes, Outdoor ponds at least 1m deep to allow fish to survive winter unless pond heater used, Ensure hole in ice for oxygen supply
How to feed fish?
Feed 2-4x/day only as much food that is consumed within 2-3 minutes + ensuring uneaten food is removed, Important not to overfeed
What to feed fish?
- Various types of commercially prepared food available,
- Should be mixed protein content & contain a range of vits & mins
- Consider the levels of water for each species feeds at choose the most appropraite food (surface/Mid/bottom = Flakes/stick/tablets etc), -
- Some fresh food may be fed dependant on speices
What is the majority of energy source for fish?
Protein - require 30-36% protein in diet
Feeding + Ponds
Well planted = Minimal additional feeding unless there is a high stocking rate, Same applies as previous, Reduce to single feed during daylight as temps decrease, No feeds when water temp <8℃
