This document discusses key areas of tilapia husbandry including water quality, systems, stock management, feeding, and disease monitoring. It emphasizes that while tilapia are tolerant of poor water quality, optimal conditions are needed to maximize growth performance. Water quality parameters like dissolved oxygen above 5mg/L, unionized ammonia below 0.1mg/L, and nitrite below 1mg/L are recommended. Tilapia grow best in intensive systems like circular tanks or raceways with water flows below 5cm/sec and photoperiods of 18 hours light. Good stock management includes uniform sizing, regular grading, and starting densities of 20kg/m3. Feeding multiple small meals per day is

1. Tilapia Husbandry
Mark Burdass

2. Key Areas
• Water Quality
• Systems
• Stock Management
• Feeding
• Disease monitoring

3. Water Quality
• Tilapia are very tolerant to poor water quality
• Often quoted as very tolerant to typically lethal
WQ parameters for other fish
• For Example
– Tolerant to DO levels of 0.1mg/l
– Tolerant to Total Ammonia Nitrogen of 16mg/l
– Tolerant to Nitrite levels of 25mg/l
• However, what’s not mentioned is the massive
effect on behaviour and production performance
these poor WQ parameters have!

4. Xu, Liu, Cuic and Miao, 2006

5. Water Quality
• To maintain good production efficiencies then
the following should be targets.
• DO Levels above 4mg/l preferably above 5mg/l
• CO2 levels should be kept below 5mg/l (for
every mg of oxygen used the fish excrete 1.4mg
of CO2)
• TAN levels below 1mg/l (<0.1mg/l UIA)
– Peak ammonia excretion is around 1 -5 hours after
feeding
• Nitrite levels below 1mg/l

6. Water Quality
• High suspended solids (SS) levels are often a
consequence of feeding in intensive systems.
• Tilapia (Oreochromis sp are filter feeders) and
so are very tolerant of high SS, and can take
levels well over 500mg/l
• However, need to be kept low (below 50mg/l)
as strongly associated with chronic disease
problems if allowed to persist

7. Water Quality
• Temperature
• One of the single most important
parameters for influencing growth
• Tilapia are very cold intolerant
• They become inactive below 16oC
• Feeding is strongly reduced below 20oC
• Sensitive to rapid temperature changes of
more than 4oC per day

8. Water Quality
• Even above 20oC there are consequences
for low temperatures
• Optimum temperatures are around 28oC
for O.niloticus.
• Temperatures below this have impacts on
growth performance.

9. Water Quality
El-Sayed & Kawanna, 2008

10. Water Quality Impact of temperature on % weight gain over 50 day
trial on O. niloticus fry
6000
5000
% weight gain
4000
3000 % Wt gain
2000
1000
0
20 25 30 35
Temperature (o C)
Impact of temperature on FCR over 50 day trial on O.
niloticus fry Impact of temperature on Cumulative Specific
Growth rate over 50 trial on O. niloticus fry
4
8
3.5
3 7.5
2.5 7
FCR
2 FCR
SGR
6.5 SGR
1.5
1 6
0.5
5.5
0
20 25 30 35 5
o 20 25 30 35
Temperature ( C)
Temperature (o C)

11. Water Quality
• Sub optimal temperatures also has an
impact on the immune system
• Tilapia will potentially become more
susceptible to disease organisms they
would normally shrug off!

12. Photoperiod
• Long photoperiods produce best results
for tilapia
• 18L:6D seems to give very good results
for growth
• Needs to be considered during the winter
months

13. Water Quality
• Water flows should be maintained to allow
self cleaning and maintain WQ
• However, tilapia are not trout! Keep flow
rates below 5cm/sec
• If water flows are too high they will
expend a lot of energy swimming and not
growing

14. Water Quality
• Salinity
• Tilapia are generally a salt tolerant
species, tolerating levels over 15 ‰
• This can be advantageous as could be
used as a general prophylactic treatment
against external parasites
• Has also been used to improve carcass
quality

15. Systems
• Hatchery Systems
• Eggs need to be kept moving
• Eggs should be incubated in McDonald
jars
• Yolk-sac fry can also be incubated this
way

17. Systems
• In intensive systems usually held in circular
tanks or raceways
• For fry production raceways are advantageous
as they have a better surface to volume ratio
– Reduces feeding competition between fry for the
floating food
• For on-growing tilapia round tanks or D ended
raceways give better flow dynamics and self
cleaning. These types of tank also reduce
aggression as there are no corners!

18. Systems

19. Stock Management
• Adult tilapia are a robust cichlid capable of
taking high levels of handling with minimal
physical damage
• However, fry are sensitive to handling.
• Also any handling will reduce growth
performance because of the stress
induced
• Keep handling to a minimum, this also
reduces risk to staff!

20. Stock Management
• Tilapia will readily form aggressive size
hierarchies that can lead to aggression and so
stress.
• To keep this to a minimum, ensure that the fish
at the start of a production cycle are very similar
in size
• Regular grading ensures that size hierarchies are
kept to a minimum
• Keep early stocking densities relatively low
(20kg/m3)
• This reduces aggression and also improves
growth potential of the fish during the start of
the production cycle

21. Stock Management
• Grading can be done with bar graders
though when they raise their fins they can
get stuck!
• It’s important to maintain reasonably
uniform size as the growth of the smallest
fish will be depressed by the more
dominant larger fish
• Some farms just grade by eye

23. Stock Management
• Stocking densities are really dictated by system capacity
• If oxygen is not being used then levels of 40kg/m3 are
relatively easy to obtain
• If oxygen is being used then levels of over 60kg/m3 are
possible
• However, a simple rule of thumb is to start relatively low
to increase growth potential and maximise FCR and SGR
• Increase stocking densities as production cycle
progresses
• Respond to deteriorating water quality parameters
• Poor water conditions may be tolerated by tilapia but
they will cause stress and so increase disease risk

24. Feeding
• Tilapia (Oreochromis) are plankton grazers not
predators!
• This means that they are best fed with multiple
meals during the day
• Feeders need to be able to ensure even food
distribution.
– Poor feeding can lead to uneven stock growth and
aggression
• Feeding by hand or good automatic feeders can
be effective
• Pellet size is important, they generally prefer
much smaller pellets compared to salmonids.

25. Feeding
• Tilapia will chew pellets so don’t be
tempted to overfeed. It can be easily
done!
• Feeding times
Size % BW per day Feed Frequency
(per day)
First feed – 1g 30 - 10 8
1 – 5g 10 - 6 6
5 – 20g 6-4 4
20 – 100g 4-3 3-4
>100g 3 3

26. Disease monitoring
• Tilapia are pretty hardy in terms of disease
• However, like most fish if they get stressed they
can get diseases.
• To avoid stress make sure that:
– Maintain a good WQ regime
– Well graded stock maintenance
– Limit handling and minimise handling stress
– Reasonable stocking densities
– Good quality food
– Good feeding regime
• Some evidence that probiotics in the feed can
maintain health in tilapia

27. Disease monitoring
• What to look for:
• Behavioural clues
– Flashing
– Erratic swimming
– Poor appetite
– Lethargy and loss of escape reaction
– Jumping
– Rapid opercular movements
• Physical clues
– Dark skin
– Eroded fins
– Mortality
– Exophthalmia
– Gill discolouration
– Excess mucus production

28. Conclusion
• Tilapia are a good aquaculture species
• Good growth rates are possible
• Very forgiving in terms of tolerances
• However, like all fish they get stressed
• Stress is a manageable phenomenon
• Maintaining a low stress environment by
good husbandry is the key to successful
production

29. Thank you