Senior High School

Aquaculture - Grade 12
Alternative Delivery Mode
Quarter 1 - Module 1: Prepare and maintain fish grow-out operation
First Edition, 2020

Republic Act 8293, section 176 states that: No copyright shall subsist in anywork of
the Government of the Philippines. However, prior approval of the government agency or
office wherein the work is created shall be necessary for exploitation of such work for profit.
Such agency or office may, among other things, impose as a condition the payment of
royalty.
Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names,
trademarks, etc.) included in this book are owned by their respective copyright holders.
Every effort has been exerted to locate and seek permission to use these materials from
their respective copyright owners. The publisher and authors do not represent nor claim
ownership over them.

Development Team of the Module

Writer/s: Reynaldo D. Baldo (SHS-SST I Pagudpud National High School)
Illustrator and Layout Artist: Reynaldo D. Baldo
Proofreader, In-House Content and Language Editors:
Management Team
Editor: Felisa T. Nolasco
Master Teacher I

ii
 Preface

This module was prepared to help you achieve the required competency in preparing
grow-out facilities. This module will be your basis and/or source of information in acquiring
knowledge and skill in preparing grow-out facilities.

This module covers all the procedures done to prepare a grow-out facilities: ponds,
tanks, pens and cags like, draining and drying, harrowing and leveling of the pond,
application of lime into the pond bottom, elimination and/or control of pest and predators,
growing of natural food setting up frames and among others.

iii
 Introduction

Rural aquaculture in the Philippine setting will be difficult to define and appreciate
without having to view it against aquaculture in general. In the country, the fisheries sector is
classified into capture fisheries, aquaculture and post-harvest, where capture fisheries is
subdivided into municipal, commercial and inland fisheries (FAO).

As an archipelago, the Philippines is considered to have one of the highest per capita
fish consumption in the world and there is a global declining trend of capture fisheries
therefore there is a call for intensified promotion of aquaculture activities in potential areas
for fish production. In addition there is a need to fill the gap in fish production as the
estimated requirement for fry in the Philippines is about 3.5 billion annually while local
production is only 2.5 billion a year (Pineda, L. 2019).

Preparation of nursery pond is an important aspect of hatcher operation because this will
determine the survival and quality of fingerlings to be produce. However, nursery stage
comes after breeding. This entails the rearing of newly hatched fish or larvae to bigger size
to encourage better preformance and survival when grown to marketable size. Nursery pond
preparation involves several steps that one must follow to ensure that the fish will be
provded with suitable conditions.

iv
 GLOSSARY OF TERMS

Assimilate - to take in and appropriate as nourishment

Aquatic weeds- unwanted plants which grow in ponds.
Chemical/Inorganic fertilizers – manufactured fertilizers containing nitrogen, phosphorous and
potassium in varying portions.
Compost- organic material(especially plants) which has been decomposed and is suitable for use as
fertilizer
decomposition - the decay or breakdown of organic materials into simple compounds available for
assimilation by phytoplankton.
Dissolved oxygen- oxygen that is dissolved in water and which respired by aquatic organisms
Diversion ditch/canal- a ditch or canal which is dug to channel excess water away from a pond,
especially during heavy rains.
Fertilizer – a substance added to water to increase the production of natural fish food organisms.
Food chain – the pathways through which nutrients added to a pond are converted into fish flesh.
Green manure- manure composed of green manure plant matter
Leach out- to be drawn out due to the presence of moisture
Manure/organic fertilizer – animal or plant matter used as fertilizer in ponds.
Microscopic – invisible to the eye without the aid of a microscope or magnifying glass.
Natural fish food organisms – plankton, insects and other aquatic organisms that fish eat.
Organic fertilizers/manure - fertilizers composed of animal or plant materials which must be
decomposed to release their minerals and nutrients.
Oxygen depletion/low oxygen – a condition, normally occurring at night, in which oxygen
dissolved in pond water has been depleted mainly because of the decomposition of organic matter
and respiration of organisms in the pond.
Phytoplankton – the plant component of plankton.
Phytoplankton bloom – an increase in phytoplankton abundance resulting from fertilization.
Plankton – the various, mostly microscopic, aquatic organisms (plants and animals) that serve as a
food for larger aquatic animals and fish.
Secchi disk – a circular disk measuring approximately 20 cm in diameter which is used to measure
the abundance of plankton in water.
Turbidity – an opaque or unclear appearance imparted to water by the presence of suspended
foreign particles (soil, plankton, etc.)
Volatilize- to turn into a gas and escape into the atmosphere.
Watershed- an area from which water drains to a single point
Zooplankton – the animal component of plankton.

v1
 Senior High School

Aquaculture NC II
12
Quarter 1 - Module 5:

Compute fertilizer requirement

1
 For the learner:
Welcome to the Aquaculture NC II. This module was designed to provide you
with fun and meaningful opportunities for guided and independent learning at your
own pace and time. You will be enabled to process the contents of the learning
resource while being an active learner. This module has the following parts.

What I Need to Know

This will give you an idea of the skills or competencies you are expected to learn in the
module.

What I Know
This part includes an activity that aims to check what you already know about the lesson
to take. If you get all the answers correct (100%), you may decide to skip this module.

What’s In
This is a brief drill or review to help you link the current lesson with the previous one.

Whats New
In this portion, the new lesson will be introduced to you in various ways such as a story,
a song, a poem, a problem opener, an activity or a situation.

What is it
This section provides a brief discussion of the lesson. This aims to help you discover
and understand new concepts and skills.

What’s More
This comprises activities for independent practice to solidify your understanding and
skills of the topic. You may check the answers to the exercises using the Answer Key at the
end of the module.

What I have Learned

This includes questions or blank sentence/paragraph to be filled in to process what you
learned from the lesson.

2
 What I Can Do
This section provides an activity which will help you transfer your new knowledge or skill
into real life situations or concerns.

Assessment
This is a task which aims to evaluate your level of mastery in achieving the learning
competency.

Additional Activities
In this portion, another activity will be given to you to enrich your knowledge or skill of the
lesson learned.

Answer Key
This contains answers to all activities in the module. At the end of this module you will
also find:

References
This is a list of all sources used in developing this module.

The following are some reminders in using this module:

1. Use the module with care. Do not put unnecessary mark/s on any part of the
module. Use a separate sheet of paper in answering the exercises.
2. Don’t forget to answer What I Know before moving on to the other activities
included in the module.
3. Read the instruction carefully before doing each task.
4. Observe honesty and integrity in doing the tasks and checking your answers.
5. Finish the task at hand before proceeding to the next.
6. Return this module to your teacher/facilitator once you are through with it.

If you encounter any difficulty in answering the tasks in this module, do not hesitate to
consult your teacher or facilitator. Always bear in mind that you are not alone.
We hope that through this material, you will experience meaningful learning and gain
deep understanding of the relevant competencies. You can do it!

What I need to know

This lesson will give you insights and knowledge in pond preparation especifically in
computing fertilizer rewuirement.

Learning Objectives:

After reading this INFORMATION Sheet, YOU MUST be able to:

3
 1. Understand the basic knowledge in computing fertilizer requirement.
2. Apply knowledge and skills in computing fertilizer requirement.
3. Explain the importance of computing fertilizer requirement in preparation of grow
out facilities.

What I know

Before you go through the lesson, try to answer this pre-test. This will enable
you to find out what you already know and what you still need to know about
“computing fertilizer requirement”.

Self-Assessment:
Multiple Choice: Choose the letter of the correct answer.

1. What are the two types of fertilizers applied in the fish pond?
A. Organic and Inorganic C. Single and Double
B. Complete and Incomplete D. None of the above

2. It is a method of pond fertilization wherein the fertilizer is placed in stock tide to bamboo
suspended in the water.
A. Platform method C. Sack method
B. Bamboo method D. Fertilization

3. Why it is necessary to fertilize ponds?

A. For the production of natural food
B. To neutralize pH of the water
C. A and B
D. None of the above

4. How do organic fertilizer work?

A. Organic fertilizers decompose and release N, P, K
B. Organic fertilizers provide attachment sites for bacteria and other microorganisms
C. Plant materials give direct nutrients to fishes
D. All of the above

5. It is a commercial fertilizer used in side dressing.

A. Organic fertilizer C. Inorganic fertilizer
B. Complete fertilizer D. Incomplete fertilizer

4
 What’s in?

A fish pond is a unique environment created by man. It must be managed properly ton
achieve good fish production. For centuries fish farmers have increased fish yields in ponds
by using inorganic or chemical fertilizers and organic fertilizers or “manures”.

What’s new?

Why fertilizes the ponds?

Microscopic green plants called algae or “phytoplankton” form the base of the food chain
for fish. All green plants need light, proper temperature and nutrients for growth. If sufficient
light and proper temperature are present, the nutrients in chemical fertilizers (nitrogen,
phosphorous and potassium) are readily assimilated by phytoplankton and their abundance
increases.

Manure contains the same nutrients. They are released and become available to
phytoplankton form dense communities pond water turns a greenish or brownish color. This
called a phytoplankton bloom.

As phytoplankton multiply, they are eaten directly by someone fish or by other mostly
microscopic aquatic animals called “zooplankton” phytoplankton and zooplankton
(collectively called “plankton”) also as food for larger aquatic organism. Through a complex
chain of interaction fertilizer production of natural food organisms eaten by fish. Different fish
may have different food preferences. Some can filter plankton while others eat aquatic
insects and others may feed on decomposing material. The following diagram illustrate this.

Measuring the effect of fertilization

Response to fertilization can be measured by the abundance of phytoplankton. When

phytoplankton is abundant, it makes water a turbid green or brownish color. If the pond water
is not very muddy, the turbidity cause by phytoplankton can serve as a measure of
phytoplankton can serve as a measure of phytoplankton abundance.

A Secchi disk is a standard way to measure visibility in water. The disk measure 20 cm
in diameter and is painted black and white in opposing quarters as shown below. A simple
disk can be made from a round can lid. The disk is attached to a wooden stick or a rope
marked off I centimeters. Measure plankton density by lowering the disk into the water with
your back to the sun while viewing the disk from directly above. The depth at which the disk
just disappears from sight is the secchi disk reading.

It is often easier for a framer to use his arm and hand instead of a secchi disk. The
principle is the same. The person’s arm become a meter stick and upturned palm of the
hand becomes a disk as illustrated below. Rules on how to interpret the result of either

5
secchi desk or arm and hand and what management actions to take depend on what fish is
being cultured and on what fertilizer is being used.

Differences between chemical fertilizers and manures

Chemical fertilizers are concentrated nutrients for green plants. The qualities that have
made them popular in modern agriculture are: 1) they can be stored for a long time, and 2)
relatively little is needed since the nutrients are in a concentrated form. These are important
advantages over manures if labor and transportation are costly. Two disadvantages of
chemical fertilizers, especially for isolated farms operated on a limited budget, are that they
are usually expensive and available only from commercial suppliers.

Another important consideration about chemical fertilizer is their potential for being
wasted. Adding chemical fertilizer to a pond initially stimulates phytoplankton growth.
However, if too much is added plankton can become so dense that sunlight penetration
through the water is restricted. When this happen algae cells may have more than enough
nitrogen and phosphorus available in the water, but they do not receive sufficient sunlight.
No additional plankton will then be produced. Keeping phytoplankton abundance within the
limits suggested for Secchi disk or arm measurement helps ensure that excess fertilizer is
not applied.

Chemical fertilizer may not be eaten directly by fish. Manure, however, can serve
several roles. It releases nutrients for phytoplankton through decomposition; certain fish can
digest specific components of manure; fish may digest by bacteria, fungi and other
organisms contained in manure even though the manure itself may no nutritional value.
Large quantities of manure are needed to fertilize pond. This is its main disadvantage. There
is a danger in adding too much manure to a pond at one time. Decomposition may deplete
oxygen in the water or cause harmful substance to accumulate. Fish may die as a result
however, with proper management this problem can be avoided or corrected in where
manures are available, they are often the fertilizer of choice.

Food chains

Nutrients in chemical fertilizer are “food” for green plants, and have no direct food value
for fish. When chemical is added to a pond, phytoplankton becomes more abundant. They
may then be eaten directly by fish or by zooplankton and insects which are subsequently
eaten by fish. This step-by-step process is called a food chain.

A step in the food chain can be eliminated by adding manure instead of chemical
fertilizer to a pond because many fish will consume manure directly. Manure may also be
eaten by zooplankton or insects which are later eaten by fish or it may be decomposed by
bacteria and another organism. Decomposition releases nutrients for assimilation by
phytoplankton. A simplified food chain illustrating direct and indirect consumption of fertilizer
nutrients by fish follows.

Chemical fertilizers for fish ponds

Chemical fertilizers are normally used to improve soil fertility and increase agricultural
crop yields. In fish ponds they stimulate phytoplankton production which increases fish
yields. They contain inert filler material mixed with three important minerals, nitrogen (N),
phosphorous (as P205) and potassium (as K20 or potash) which are needed by
phytoplankton in fish ponds. A commonly available chemical fertilizer is 12-24-12. It contains
12 percent nitrogen, 24 percent phosphorous and 12 percent potassium. This equals 48%

6
fertilizer an 52% filler material by weight. Fertilizers high in phosphorous are especially
good for phytoplankton production in fresh water ponds. New fresh water ponds and salt
water ponds also require nitrogen. After several years, the organic content in the mud of
these ponds will increase and may be needed for increased production in aged ponds. The
Table below is a list of several chemical fertilizers used in fish ponds and their compositions.

Table: NPK Composition of several fertilizers used in fish ponds

NPK composition of different fertilizers
Fertilizer Percent Composition
(N) (P2O5) (K2O)
Ammonium nitrate 33-35 0 0
Ammonium sulphate 20-21 0 0
Ammonium phosphate 16 20 0
Calcium nitrate 15.5 0 0
Diammonium 18 48 0
phosphate
Double superphosphate 0 32-40 0
Muriate of potash 0 0 50-62
Potassium nitrate 13 0 44
Potassium sulphate 0 0 50
Sodium nitrate 16 0 0
Superphosphate 0 18-20 0
Tripple superphosphate 0 44-54 0
Urea 42-47 0 0

Applying chemical fertilizers to ponds

Weekly application rates for chemical fertilizers may range from 1.25 to 1.75 grams of
P205/m2 of pond surface area. The amount of fertilizer needed can be calculated using
information from table 1. For example: to calculate the amount of superphosphate needed to
give 1.25 grams of P205/m2 in a 100 m2 pond the following calculation is done.

[ (1.25 g/m2) / 0.20] x 100 m2 = 0.625 Kg/100 m2/week

In this calculation 0.20 (or 20%) is the percent P205 content from Table. The pond would
receive an initial application of 0.625 kg of fertilizer. The weekly amount would then be
increased or decreased as needed based on Secchi disk readings.

Solid chemical fertilizers should not be thrown into a pond. They will sink to the bottom
and nutrients will lost in the mud. Chemical fertilizers can be applied in several ways to keep
them out of the bottom mud.

1.Platform method:

A table platform may be built of wood, bamboo or zinc sheets. The platform surface rests
30 cm below the water surface. Place a two-week dose of fertilizer on top of the platform.
Wave action will distribute nutrients as they dissolve. Fertilizer is added as needed to
maintain the desired phytoplankton abundance. This usually occurs when the water clears
enough to allow the platform to be seen.

2.Nylon bag:

7
 Nylon or cloth bags used to transport fertilizer, onions, rice or flour may be filled with the
required dose of fertilizer and tied to a post below the water surface. Begin with a two-week
dose of fertilizer. Dissolved nutrients pass through the bag into the water. More than one bag
may be needed for large ponds. Add fresh fertilizer periodically and discard undissolved filler
material left in the bag.

3.Dissolved in water:

The quantity of fertilizer needed may be dissolved in buckets of water. Resulting “liquid
fertilizer” is then dipped out of the bucket and splash over the entire pond surface. This
method disperses nutrients into the water column faster than other methods of fertilization
and allows a phytoplankton response to be achieved quickly. Best results are obtained by
adding liquid fertilizer in daily amounts. Farmers will visit their ponds daily to measure
phytoplankton abundance and will be made aware of management needs.

Some reasons for poor response to chemical fertilization

A pond will respond to fertilization by turning green. This may happen within 24 hours. If
a pond does not turn green within one to six weeks of fertilization one of the following factors
may be responsible.

1.Muddy water:

When mud particles are suspended in pond water and sunlight penetration is reduced
phytoplankton growth will be inhibited in spite of fertilization. Control the problem by
correcting its cause.
a) Plan grass on newly constructed pond dikes to control erosion.
b) Keep the surrounding watershed planted to prevent and control erosion.
c) Channel muddy water away from ponds by building diversion ditches.
d) Do not fill a pond by muddy water.
e) Muddy ponds can sometimes be cleared by adding organic matter and fertilizer to the
water.

It may take several weeks for organic matter to effectively remove suspended mud
particles. Once water clears to a depth of 20 to 30 cm fertilization may be attempted. Some
recommendations include:
1) Make two or three applications of animal manure at 20 kg/100 m2 of pond.
2) Make one or more application of 20 to 40 kg of superphosphate/100 m2 at 2-3-week
intervals.

2. Too much shade:

Phytoplankton are green plants and need sunlight for growth. A fish pond shaded from
sunlight will not respond to fertilization. Prevent tall plants and trees from shading your pond.
Routine branch trimming and dike cleaning are necessary.

3.Water weeds:

DO NOT FERTILIZE WEEDY PONDS! Fertilizer is added to fish ponds to provide

nutrients for phytoplankton. If your pond is full weeds, adding fertilizer will only make the
weeds grow faster. Once weeds are established, they steal nutrients from the phytoplankton.

8
Weeds also shade the water surface and prevent sunlight penetration which is essential for
phytoplankton growth. Remove weeds before fertilizing.

4. Excess water flow:

People not familiar with fish culture often think fish should be cultured in constantly
flowing water. Flushing water through a pond may help remedy situations where fish are
under stress or appear sick, but this action can also flush fertilizers and nutrients out of a
pond. This inhibits phytoplankton growth. To avoid this do not allow a continuous flow of
water through the pond. Add only enough water to replace evaporation and seepage, or
correct problems. Control excessive water flow by using the following measures appropriate.
1. Build diversion ditches to channel excess water around the pond.
2. Enlarge the existing pond and/or construct another pond above the existing one in a
terrace fashion.
3. Build inlet control structures such valves, flood gates, etc.

5.Lime may be needed:

In many areas the only water source for ponds is rain that runs off the surrounding
watershed. This water may be acidic. Fish may not survive or grow well in ponds which are
filled with this water unless lime is applied to neutralize the acidity. Liming will promote
phytoplankton growth and increase fish production.

Apply lime into a pond by spreading the needed amount evenly over the dry bottom
before filling it with water. If a pond is already full, lime maybe spread over the surface with a
shovel. In large ponds, a boat may be use to spread lime evenly over the surface. Ponds
requiring lime should be limed after each draining if lime available at a reasonable price. If
pond soil has a pH above 6.5, lime is not needed. The previously mentioned factors
inhibiting response to fertilizers must be corrected before liming can enhance the effect of
fertilization.

The amount of lime added to a pond depends on the acidity. Soil testing laboratories
equipped to measure acidity of pond bottom soils can make specific recommendations on
the amount of lime required to neutralize acidity. In the absence of such assistance, a
rule-of-thumb is that 1000 to 2000kg of agricultural lime/ha (this is 10 to 20kg/100m2) will
neutralize soil acidity under most conditions. There are several forms of lime, but finely
ground agricultural limestone is best. Quicklime is dangerous. It burns if it is inhaled or
touches the skin. Farmers using quicklime should exercise extreme care.

Table: Application rates for different liming materials when soil testing is not
available
1. Coarsely ground agricultural lime: 1000 to 2000 kg/ha
2. Finely group agricultural 1000 to 1200 kg/ha
limestone:
3. Hydrated(builders or slaked) lime: 600 to 1000kg/ha
4. Quicklime: 500 to 800 kg/ha

It will not hurt to add lime if the reason for poor fertilizer response is not clear.
Agricultural lime is safe to apply while fish are still in the pond. Applying excess quicklime or
hydrated lime can kill fish. Quick or hydrated lime should be applied before stocking fish. If
several applications of the lime fail to increase production of phytoplankton other actions
may be necessary to improve conditions in the pond.

9
6.Not enough fertilizer:

Sometimes the amount of fertilizer applied is insufficient to stimulate phytoplankton

response. If this suspected increase the amount and/or frequency of application

Storing chemical fertilizers

Do not store chemical fertilizers longer than necessary. If storage is required place
chemical fertilizers in a dry,well-protected location. Excess humidity can damage the
fertilizer. Bags of fertilizer can be stored on a wooden or bamboo platforms elevated above
ground.

Some general considerations

1. Buy the fertilizer you need. Some companies sell a variety of fertilizers. Inquire from
extensionists and other farmers which fertilizers they recommend for fish ponds. Fertilizers
grades are usually marked on the bags or box containing the fertilizer. Some companies
guaranty this analysis. For example, a 20-20-5 grade should mean that the fertilizer contains
20% nitrogen, 20%phosphorus and 5% potassium by weight. By chemical fertilizers from a
reputable dealer.

2. It is difficult to determine when chemical fertilizer is no longer usable. Nitrogen in

chemical fertilizer can volatilize when it comes in contact with moisture. The container
holding the fertilizer becomes wet if this happens. Other nutrients may be leached out during
this process. Fertilizer bags and boxes usually have an inner plastic liner to guard against
damage from moisture. Do not buy fertilizer in containers which appear wet or which have
been stored in a damp area.

Organic fertilizer for fish ponds

Organic fertilizers are usually animal manures or plant wastes and cutting (green
manure). manure from chickens, goats, sheep, ducks, pigs, rabbits, cattle and horses are
excellent fertilizers for fish ponds. Other examples of organic fertilizers suitable for ponds are
digested sludge from biogas generators, molasses from sugar cane factories, composted
vegetation, table scraps and waste water from animal slaughter houses. Examples of
materials that are NOT good organic fertilizers are rice hulls, sugar cane stalks, sawdust or
other materials that require a long time to decay.

How do organic fertilizer work?

1. Organic fertilizer decomposes and release nitrogen, phosphorous and potassium which
are used by phytoplankton for growth and reproduction. In this way more natural food
organism are produced for fish to eat.
2. Organic fertilizers, especially animal manures, provide nutrients and attachments sites
for bacteria and other microscopic organisms. These organisms provide nutrients for fish
even though in some cases the manure itself may have no direct food value when eaten.
3. Many “green manures” and the undigested food in animal manures are digestible and
provide direct nutrition when eaten by fish. This is in addition to their effect as fertilizers
and attachment sites for fish food organisms as described above. The result is
enhanced fish production.

10
Amount or manure needed

1. Animal manures:

Manures vary in nutrient quality depending on the quality of food eaten by the animals.
For example, animals like pigs and chicken which are given high quality commercial rations
will have manure higher in nutrient quality than animals like horses and cattle which feed on
grasses. The amount of pig or chicken manure needed for a pond is therefore less than the
amount of cattle or horse manure to achieve equivalent result. The moisture content of the
manure also affects its quality. Dry manure will have more or some chemical nutrients than
an equal of weight of wet manure because it is more concentrated, but the food value may
be lower because bacteria and other organism may have already removed much of the
digestible material.

Animal manures are usually applied to ponds on the basis of weight or per area of pond
surface (kilograms of manure per hectare, per 100 square meters, etc.) or on an animal per
area basis such as one pig per 100 square meters of pond surface area. Use the table as a
rule-of-thumb to determine approximately how many kilograms of manure or how many
animals are needed for the desired effect. By dividing the weekly dose into daily applications,
low oxygen problems will be less likely to occur and food in the manure will be more
effectively utilized by the fish.

Table: Animal manure application rates and number of animals needed to supply
manure to 100m2 of ponds.
Manure Source Application Rate Number of Animals
(kg/100m2/week) (per 100m2 of pond)
Cattle 10 a. 0.3 (all day)
b. 0.6 (night only)
Chicken 6-8 10-15
Duck 6-8 10-15
Goat/Sheep 10 a. 4 (all day)
b. 8 (night only)
Horse/Donkey 10 c. 0.5
Pig 6-8 d. 0.5-1

Chicken, pigs and ducks may be confined and fed a commercial ration. Chickens may
be raised over pig pens which are built over fish ponds. Uneaten food and manure can then
be washed or fall directly into fish ponds. Cattle, buffalo, sheep and goats are normally
pasture-fed. Their manure falls in the fields where it is difficult to collect and apply to ponds.
If these animals are corralled and fed near ponds, manure can be easily collected or flushed
into ponds. Animals may be corralled constantly or only at night. Less manure will be
available if the animals are confined only at night. More animals will therefore be needed per
pond surface area than if constant confinement is used.

Large animals should not have unrestricted access to ponds because their hooves will
breakdown pond dikes causing shallow weedy areas to develop. These areas become
mosquito breeding grounds. Ponds should be protected with the fence and access of large
animals limited to one small area of pond shoreline. Manure and urine will be concentrated
there and flushed into the pond during rains.

11
2. Plant or “green” manure

Vegetable matter, grasses, garden weeds, spoiled fruits and vegetables and other plant
wastes can be used as fish pond fertilizer. They may be chopped into small pieces and
mixed together into compost pile. A mixture of animal and green manure s provides a good
fertilizer. Compost should be kept moist, not saturated or dry, so it rots quickly. To control
acidity 2.5 kg of finely ground lime may be mixed with 100 kg of compost material. Compost
piles should be turned and mixed weekly to promote aeration and rapid decomposition.
Compost piles shrink as the material decomposes.

Apply compost to fish ponds at a rate of 20 to 25 kg/100m2 of pond surface area every
ten days as a rule-of-thumb. The size of pond that can be effectively fertilize depends upon
the quantity of compost material.

Place compost material into corrals built of bamboo or wood measuring at least
two-meter-long by one meter wide. Pile cut weeds, grasses and other soft plants and scraps
inside the frame. Stir the pile weekly to promote continued decomposition. Compost can be
withheld and/or removal from corrals if low oxygen develops until the problem is corrected.

Oxygen problems caused by organic fertilizers

Oxygen depletion frequently occurs after large doses of manure are added to pond at
irregular intervals. This is the most serious condition with using organic fertilizers. As manure
decomposes oxygen is consumed from the water.

When oxygen is low fish come to the surface of the water and appear to gulping air.
They are trying to breath. This would be similar to a person who has been breathing under a
cover for an extended time. Oxygen is used up and the cover must be removed to let in fresh
air.

In ponds low oxygen usually occurs at night and is lowest just before dawn because
phytoplankton have not produced oxygen during the night. Low oxygen can also become a
serious problem when secchi disk reading fall below 20cm indicating that plankton are too
abundant. See details on reading a secchi disk in Introduction for Fish pond fertilizer. Low
oxygen can kill fish. If only a few fish die every day the problem may be disease. If large
numbers die suddenly at night low oxygen is probably the cause. Even if fish do not die from
low oxygen, they are weakened and more likely to become sick.

Avoiding and correcting low oxygen problems

1. Suspend fertilizer application until low-oxygen problem has been corrected and fish stop
gulping at the water surface.
2. Add fresh water to the pond immediately to revive the fish, and continue adding water until
the fish stop gulping at the surface
3. While adding fresh water, drain some of the old water off pond bottom. The bottom layers
have the least oxygen.

Application rules for organic fertilizer

1. The first application may be two weeks prior to stocking fish to increase natural food
abundance. When using manure provided by enclosed livestock, place the animals to their
pens and begin them feeding them two weeks prior to stocking fish. This is especially true if
the pond was not previously manured

12
2. Do not over fertilizer. Manure should be applied to ponds to keep plankton abundance
within recommended limits.

3. Avoid adding large doses of manure at irregular intervals. Maintain a scheduled routine or
adding manure based on observations of water quality. This allows decomposition to
proceed at a slower rate and avoids oxygen depletion.

4. Organic fertilizer can be used in combination with chemical fertilizer. If the pond is muddy
add manure first to precipitate suspended soil particles. This will enhance the effectiveness
of chemical fertilizers in increasing phytoplankton abundance.

5. Keep sechi disk reading of plankton abundance within the range of 20 to 30 cm and
check the pond before sunrise to detect oxygen problems. Have fresh water available for
flushing a pond if low oxygen develops. Suspend or reduce fertilization until the low oxygen
problem is corrected.

6. Remember that many organic fertilizers are also eaten by fish. Weekly amount of manure
can be divided into smaller daily doses to facilitate this. Daily doses are best applied at
mid-morning to avoid creating oxygen problems.

What is it?

In the discussion on the computation of fertilizer requirement, answer the following

briefly and give evidences and/or justification of your answers if needed.

1. Is fertilizer applied to increase the growth of natural food? Why or why not?

2. Is broadcasting the best method in applying fertilizer into the pond?

3. Differentiate the two types of fertilizers

Rubrics to be used in grading:

4  Explanation or answer demonstrates strong understanding of the concept
 Student completely explain the concept using appropriate vocabulary
3  Explanation demonstrates good understanding of the concept
 Explanation is nearly complete but some gaps exist; vocabulary is appropriate
2  Explanation demonstrates some understanding of concept
 Explanation is vague or inconsistent with missing or inappropriate vocabulary
1  Explanation demonstrates limited understanding of concept
 Minimal explanation is provided and explanation is unclear with missing and
inappropriate vocabulary
0  Student was unable to offer any explanation

13
 What more?

Analyze the following questions or situation and answer. Present some proof or
justification of needed to solidify your answer.

1. Could you apply fertilizer even if fish are present in the pond? What do you think will
happen?

2. How often do you think is the application of fertilizer in the pond?

3. What are the three basic nutrients supplied by the fertilizer? Give the benefits of each
nutrients to the plants.

Rubrics to be used in grading:

4  Explanation or answer demonstrates strong understanding of the concept
 Student completely explain the concept using appropriate vocabulary
3  Explanation demonstrates good understanding of the concept
 Explanation is nearly complete but some gaps exist; vocabulary is appropriate
2  Explanation demonstrates some understanding of concept
 Explanation is vague or inconsistent with missing or inappropriate vocabulary
1  Explanation demonstrates limited understanding of concept
 Minimal explanation is provided and explanation is unclear with missing and
inappropriate vocabulary
0  Student was unable to offer any explanation

What I have learned?

LET US REMEMBER:

1. The most serious condition that occurs when using organic fertilizer is __________.

2. What do you call the plant wastes that can be used as fertilizer?

3. The two types of fertilizers that can be applied in ponds are _______, __________.

4. _________ are microscopic green plants used as food for fishes.

5. What do you call when there is an increase in the number of algae present in the
pond?

14
 What I can do?

Understand each question and give your answers

1. Besides secchi disc, what other instrument or tool can be used to measure the effect
of fertilization?

2. What is the indicator that the fertilizer or the fertilization is effective?

3. What are the factors that you need to consider in applying fertilizers?

4. Give the types of organic manure suitable for fish ponds.

Rubrics to be used in grading:

4  Explanation or answer demonstrates strong understanding of the concept
 Student completely explain the concept using appropriate vocabulary
3  Explanation demonstrates good understanding of the concept
 Explanation is nearly complete but some gaps exist; vocabulary is appropriate
2  Explanation demonstrates some understanding of concept
 Explanation is vague or inconsistent with missing or inappropriate vocabulary
1  Explanation demonstrates limited understanding of concept
 Minimal explanation is provided and explanation is unclear with missing and
inappropriate vocabulary
0  Student was unable to offer any explanation

Assessment

Self-Check:

Multiple choice: Choose the letter of the correct answer

Multiple Choice: Choose the letter of the correct answer.

1. What are the two types of fertilizers applied in the fish pond?
A. Organic and Inorganic C. Single and Double
B. Complete and Incomplete D. None of the above

2. It is a method of pond fertilization wherein the fertilizer is placed in stock tide to bamboo
suspended in the water.
A. Platform method C. Sack method
B. Bamboo method D. Fertilization

15
3. Why it is necessary to fertilize ponds?
A. For the production of natural food
B. To neutralize pH of the water
C. A and B
D. None of the above

4. How do organic fertilizer works?

A. Organic fertilizers decompose and release N, P, K
B. Organic fertilizers provide attachment sites for bacteria and other microorganisms
C. Plant materials give direct nutrients to fishes
D. All of the above

5. It is a commercial fertilizer used in side dressing.

A. Organic fertilizer C. Inorganic fertilizer
B. Complete fertilizer D. Incomplete fertilizer

Additional activity

Activity Sheet 1.1

I. Directions: Answer the following questions

1. 100 kgs. of 8-12-5 fertilizer grade from superphosphate (20% P2O5), urea (45% N) and
muriate of potash (60% K2O). do you need a filler? If yes, how many? If no, why?

2. Complete the table below

Name of fertilizer Chemical Complete/Incomplete/
formula/Composition organic
Urea
(NH4)3PO4
Sargassum seaweeds
(NH4)2SO4
NPK fertilizer 14-14-14

16
 Answer key

Self-Check:
1. A
2. B
3. C
4. D
5. D

References

Bocek, A. (ed.). Introduction to Fishpond Fertilization. International Center for Aquaculture

and Aquatic Environments, Swingle Hall, Auburn University, Alabama 36849-5419 USA

Bocek, A. (ed.). Chemical Fertilizers for Fish Ponds. International Center for Aquaculture
and Aquatic Environments, Swingle Hall, Auburn University, Alabama 36849-5419 USA

Bocek, A. (ed.). Organic Fertilizers for Fish Ponds. International Center for Aquaculture and
Aquatic Environments, Swingle Hall, Auburn University, Alabama 36849-5419 USA

Boyd, C.E. 1980. Water Quality in Warm Water Fish Ponds. Alabama Agricultural
Experimental Station, Auburn University, Auburn, Alabama

Boyd, C.E. 1982. Water Quality in Warm Water Fish Ponds. Alabama Agricultural
Experimental Station, Auburn University, Auburn, Alabama

Mair, G.C and T.A. Abella (eds). 1997. Technoguide on the Production of Genetically Male
Tilapia (GMT). Freshwater Aquaculture Center (FAC), Central Luzon State University,
Nueva Ecija, Philippines

Stickney, P.R. 1990. Principles of Aquaculture. John Wiley and Sons, Inc. Washington, USA

17
 Senior High School

Aquaculture NC II
12
Quarter 1 - Module 6:

Apply fertilizer to enhance growth of

natural food

18
 For the learner:
Welcome to the Aquaculture NC II. This module was designed to provide you
with fun and meaningful opportunities for guided and independent learning at your
own pace and time. You will be enabled to process the contents of the learning
resource while being an active learner. This module has the following parts.

What I Need to Know

This will give you an idea of the skills or competencies you are expected to learn in the
module.

What I Know
This part includes an activity that aims to check what you already know about the lesson
to take. If you get all the answers correct (100%), you may decide to skip this module.

What’s In
This is a brief drill or review to help you link the current lesson with the previous one.

Whats New
In this portion, the new lesson will be introduced to you in various ways such as a story,
a song, a poem, a problem opener, an activity or a situation.

What is it
This section provides a brief discussion of the lesson. This aims to help you discover
and understand new concepts and skills.

What’s More
This comprises activities for independent practice to solidify your understanding and
skills of the topic. You may check the answers to the exercises using the Answer Key at the
end of the module.

What I have Learned

This includes questions or blank sentence/paragraph to be filled in to process what you
learned from the lesson.

19
 What I Can Do
This section provides an activity which will help you transfer your new knowledge or skill
into real life situations or concerns.

Assessment
This is a task which aims to evaluate your level of mastery in achieving the learning
competency.

Additional Activities
In this portion, another activity will be given to you to enrich your knowledge or skill of the
lesson learned.

Answer Key
This contains answers to all activities in the module. At the end of this module you will
also find:

References
This is a list of all sources used in developing this module.

The following are some reminders in using this module:

1. Use the module with care. Do not put unnecessary mark/s on any part of the
module. Use a separate sheet of paper in answering the exercises.
2. Don’t forget to answer What I Know before moving on to the other activities
included in the module.
3. Read the instruction carefully before doing each task.
4. Observe honesty and integrity in doing the tasks and checking your answers.
5. Finish the task at hand before proceeding to the next.
6. Return this module to your teacher/facilitator once you are through with it.

If you encounter any difficulty in answering the tasks in this module, do not hesitate to
consult your teacher or facilitator. Always bear in mind that you are not alone.
We hope that through this material, you will experience meaningful learning and gain
deep understanding of the relevant competencies. You can do it!

What I need to know

This lesson will give you insights and knowledge in pond preparation especifically in
applying fertilizer to enhance the growth of natural food.

Learning Objectives:

After reading this INFORMATION Sheet, YOU MUST be able to:

20
 1. Understand the basic knowledge in applying fertilizer to enhance the growth of
natural food.
2. Apply knowledge and skills in applying fertilizer to enhance growth of natural food.
3. Explain the importance of applying fertilizer to enhance the growth of natural food in
the preparation of grow-out facilities

What I know

Before you go through the lesson, try to answer this pre-test. This will enable
you to find out what you already know and what you still need to know about
“applying fertilizer to enhance the growth of natural food”.

Self-Assessment:
Multiple Choice: Choose the letter of the correct answer.

1. The following are types of natural food maybe present in the pond except ____?
A. Lablab B. Lumut C. Brown algae D. Rice bran

2. It is a collective term for microscopic organisms suspended in the water.

A. Lumut B. Plankton C. Phytoplankton D. Zooplankton

3. This is a filamentous green alga present in the ponds.

A. Lumut B. Plankton C. Zooplankton D. all of the above

4. Which of the following is the component of lablab in plants?

A. Blue green algae C. Green algae
B. Diatoms D. Detritus

5. It is a complex association of minute plants and animals forming a brownish, greenish,

yellowish mat on the pond bottom and sometimes float on the pond surface as patches.
A. Plankton B. Lablab C. Lumut D. Rice bran

What’s in?

Aquaculture animals have to obtain all their nutritional requirements except for part of
the mineral requirement through the foods they consume. In nature, most of them subsist on
live foods consisting pf plants and animals obtained from the environment, but some do
ingest and possibly utilize detritus along with associated organisms.

Experience in aquaculture seems to show that most adult finfish and crustaceans can be
weaned to accept inert foods, even though there are advantages in providing some live

21
foods. But larval stages of many of these species have to depend entirely on live food. The
initial source of food for many larval organisms is phytoplankton.

What’s new?

GROW NATURAL FOOD

Under natural conditions aquaculture systems like ponds are stocked with fish when
abundant growth of natural food is present. This is obtained with correct fertilizer application
which will be discussed in the next learning activity.

If natural food is available in sufficient amount it is enough to support the maximum

growth of fish. Basically, natural fish food organisms are the ideal food for fish.

Why natural food?

The nutritional value of natural food organisms in pond is enough to support maximum
fish growth. Natural food is rich in protein. Often containing 40-60% protein in dry matter
basis. Albertcht and Breitsprecher (1969) stated that mean protein, carbohydrates and lipid
content of fish food organisms in ponds are 52.1, 27.3 and 7.7 %, respectively.

What are the classes of natural food?

1. Chlorophyceae

These are plankton that make up an extremely large and important class of green algae.
It includes unicellular, colonial, or filamentous algae. Cells of the unicellular and colonial
Chlorophyceae may have two or more flagella.

Plankton that belongs to this class are almost entirely restricted to freshwater and
terrestial habitat. The main feature of this class is the use of starch as the principal food
reserve and the green chloroplasts with chlorophylls a and b.

2. Cyanophyceae

Cyanophyceae is a class of blue-green algae and coliform bacteria. These are algal-like
bacteria with photosynthetic capabilities that can contaminate surface water supplies mostly
during warm summer months.

3. Bacillariophyceae

Bacillariophyceae has been used to refer to all diatoms or to refer to the raphe-bearing
pennate diatoms.

22
There are three types of natural food grown for nursery operations
A. Lab-lab

Described as the complex association of minute plants and animals that form a brownish,
greenish or yellowish mat on the pond bottom and sometimes float on the pond surface as
patches. This comprises of several species of blue-green algae, green algae, diatoms,
rotifers, crustaceans, larvae, insects, roundworms and detritus.

Lab-lab grows well during the dry months in ponds with hard bottoms and salinities of
25-32 ppt. a pond with abundant growth of lab-lab can produce 1,5000-2,500 kilograms per
hectare per year of fish. This food is usually desired for milkfish.

How to grow lab-lab?

1. Spread chicken manure evenly over the pond bottom.
2. For a more rapid effect mix fertilizer with water in plastic containers and let it
stand overnight. Spread evenly over the pond the next day.

Table 10. Recommended rate of fertilizer per hectare

New ponds Old ponds
Crop/cycle
(1-4 years) (at least 5 years)
1 st
2,000 kg/ha 1,500 kg/ha
2nd 1,000 kg/ha 500 kg/ha
3rd
500 kg/ha 500 kg/ha
4 th
500 kg/ha 500 kg/ha

3. Fill the pond with water up to 5 cm depth.

4. Allow the pond to dry for 3 days.
5. Refill water to an average depth of 7.5-10 cm.
6. Apply16-20-0 at 15 kg/ha every weekly but not less than 3 days prior stocking.
7. Three days before stocking slowly drain 25% of the pond water.
8. Refill with water to the desired level (20-30 cm)
9. Add more water slowly to avoid distributing the lab-lab.
10. Maintain the level of water.
11. Stop fertilization 20 days before harvest.

B. Lumut

This is a filamentous or grass green algae or lumut such as Chaetomorpha linum (Lumut
jusi), Cladophora sp. and Entermorpha intestinales (bitukang manok) may be grown in areas
where lab-lab grows poorly. The ideal pond condition for lumut is with soft bottom, salinity of
25 ppt and below and water depth of 20-60 cm.

Lumut is poorly digested by milkfish fry and fingerlings. This is usually decomposed and
dried before feeding for better results. This natural food is basically grown for milkfish.

23
How to grow lumut?
1. The same fertilization program used for lablab is applied.
2. Growth naturally occurs but seeding maybe necessary when few lumut grew.
3. Lumut seed stock may be taken from ponds where they grow or from green-algae
nurseries.
4. Select fibrous or silky types.
5. Plant by staking, sowing or speaking.
6. Unlike lab-lab, abundant growth is not totally needed because of space
competition with fish.
7. Pond grown with lumut may produce 900-1250 kg/ha/year of fish.

What is silo method?

Silo method is concept derived from agriculture. This method is a storage of silage for
livestock feed which can make production more efficient. Silo is tested by SEAFDEC/AQD
as an alternative for broadcasting, a laborious and strenuous method. For aquaculture, a
similar method is used in Taiwan where chicken manure (1-2 tons/ha) and rice bran
(600-1,200 kg/ha) are placed in perforated bags set at equal distances within the pond
system. The platform method is used for inorganic fertilization. The silo and the platform
methods are based on the principle of gradual release of nutrients into the water and its
distribution by water movement.

How to grow lab-lab using silo method?

1. Completely dry the pond bottom for 1-2 weeks
2. Sink three bamboo wicker baskets into the dried pond bottom to about 1/3 its
height with equal distant from each other
3. Equally divide a mixture of chicken manure at 2,000 kg/ha and rice bran at 150
kg/ha and urea (45-0-0) among the baskets
4. Make a basal application of mono ammonium phosphate (16-20-0) at 50 kg/ha and
urea (45-0-0) at 25 kg/ha to make the breakdown of organic fertilizer fast
5. Fill the ponds gradually with water from depth just covering the pond bottom until
40 cm is reached in one to one-and-a half months time
6. Broadcast inorganic fertilizer every 15 days at 25 kg/ha of 16-20-0 and 12.5 kg/ha
or urea
7. With this method there is moderate to abundant growth of lab-lab (floating type, the
more nutritious type)
8. Lab-lab growth is high even up to 90 days of culture unlike when broadcast method
is used, lablab growth is good only for 60 days.

C. Plankton

This is the collective term used for microscopic organisms suspended in water. It is not
as widely grown as lab-lab for milkfish, but it is for tilapia and other freshwater culture
species.

24
 Some fishermen however, grow lab-lab in the dry season and plankton in the wet
season. Production ranges from 600-1200 kg/ha/year.

How to grow plankton?

1. Drain the pond
2. Dry the pond under the sun until it cracks
3. Fill with water after 1 to 7 days
4. Increase water to an average depth of 60 cm but it is better if up to 75-100 cm
5. Apply inorganic fertilizer on a platform or sack during or after filling the pond
6. Rates of application are:
18-46-0 at 22 kg/ha
16-20-0 at 50 kg/ha
16-20-0 at 25 kg/ha with 0-20-0 at 25 kg/ha
7. Stock the pond with fry after one week of fertilizer application
8. Apply fertilizer at the same rate every after two weeks
9. Maintain water visibility at 20-30 cm
10. Stop fertilizer application two weeks before harvest

Types of Plankton
Microplankton
These are also called net plankton. Composed of organisms that can be seen with the
aid of a microscope.

Macroplankton
These are plankton that composed of organisms that can be seen by the naked eye.

Zooplankton
These are plankton composing different animal organisms in the pond.

Phytoplankton
These are plankton composing different plant organisms in the pond.

Macrophytes that can be used as natural food

1. Azolla

Azolla (mosquito fern, duckweed fern, fairy moss, water fern). Azolla is a highly
productive plant. It doubles its biomass in 3–10 days, depending on conditions. It’s high in
protein and minerals, fixes nitrogen, is palatable to chickens, pigs, goats, ducks and cows,
and can be grown on any closed body of water.

How to grow Azolla?

1. Gather azolla, and bring it home in a plastic cover, then put it in a tub that has water in it. It
will be fresh for only 2 days. It should not be exposed to sunlight.
2. Make a pit that is 5 feet by 3-3 ½ feet.
3. Now fill the pit with water.

25
4. Fertilize with pre decomposed animal manure
5. Put the azolla

2. Duckweed

Duckweed, or water lens, are flowering aquatic plants which float on or just beneath the
surface of still or slow-moving bodies of fresh water and wetlands. Duckweed is an important
high-protein food source for waterfowl and also is eaten by humans in some parts of
Southeast Asia. As it contains more protein than soybeans, it is sometimes cited as a
significant potential food source.

How to grow duckweed?

1. Collection of duckweed
2. Fertilize the pond with pre-decomposed manure
3. Fill the pond with freshwater and add the duckweed
4. Like many plants, duckweed will thrive in direct sunlight

Some plankton that can be produced by fertilization of ponds

1. Euglena sp.
They are protists, which means they show
characteristics seen in both plants and animals.
Carry out photosynthesis using chlorophyll pigments
and also feed on other organisms by engulfing them
in their cell membranes through a process known as
phagocytosis. Often identified by their red eyespots
and the presence of flagella, which they use to
detect light.

2. Navicula sp.
A genus of boat-shaped algae, primarily aquatic,
eukaryotic, and photosynthetic organism. It is a diatom
known for its ability to creep about on each other. It is
thought that around the outside of navicula’s shell is a
girdle of protoplasmthat can flow and thus act as a tank
track.

26
3. Clamydomonas
Big genus of round, oval or cylindrical. A motile
unicellular algae. Two anteriorly inserted whiplash
flagella used in swimming. Eyespot present in the
anterior portion of the chloroplast. It consist of two or
three, more or less parallel rows of linearly arranged fat
droplets.

4. Tintinopsis
Syringe-like shape in nature. Complex
single-cell (Eukaryota) organisms. The
hair-like projections pointing out of the top of
the shell are the cilia of the ell. The cilia
generate a water flow across the mouth of
the cell, bringing food into contact and move
the tintinnid. Their swimming pattern is rather
‘jumpy’ or ‘dancing’- they are part of the
‘choreotrichs’ which means dancing hairs
from their swimming behavior and cilia.

What is it?

You have just learned how to grow natural food for fishes in your fishponds especially in
for grow-out culture. You also learned about the different natural foods grown and can be
grown for your fishes in the pond. To summarize the lesson answer the following questions.

1. What are the natural foods grown for fish?

2. What natural food is desired for milkfish?

3. What natural food is desired for tilapia?

Rubrics to be used for grading:

4  Explanation or answer demonstrtaes strong understanding of the concept
 Student completely explain the concept using appropriate vocabulary
3  Explanation demonstrates good understanding of the concept

27
  Explanation is nearly complete but some gaps exist; vocabulary is appropriate
2  Explanation demonstrates some understanding of concept
 Explanation is vague or inconsistent with missing or inappropriate vocabulary
1  Explanation demonstrates limited understanding of concept
 Minimal explanation is provided and explanation is unclear with missing and
inappropriate vocabulary
0  Student was unable to offer any explanation

What more?

Answer the following briefly and give explanation if needed for justification of your
answers.

1. What should be applied in pond to induce the production of natural food?

2. When is natural food grown?

3. Why grow natural food?

Rubrics to be used in grading:

4  Explanation or answer demonstrtaes strong understanding of the concept
 Student completely explain the concept using appropriate vocabulary
3  Explanation demonstrates good understanding of the concept
 Explanation is nearly complete but some gaps exist; vocabulary is appropriate
2  Explanation demonstrates some understanding of concept
 Explanation is vague or inconsistent with missing or inappropriate vocabulary
1  Explanation demonstrates limited understanding of concept
 Minimal explanation is provided and explanation is unclear with missing and
inappropriate vocabulary
0  Student was unable to offer any explanation

What I have learned?

LET US REMEMBER:

1. _________ is a natural food that is also called water lens.

2. A natural food that is filamentous in nature is ____________.

3. __________ is a complex association of phytoplankton and zooplankton.

4. What do you call the blue green algae?

28
5. What class does the navicula sp belong?

What I can do?

Complete the table below.

Name of natural food/ Where it thrives?/ How to

where does it feeds? grow?

29
 Assessment

Self Check:

Multiple choice: Choose the letter of the correct answer

1. The following are types of natural food maybe present in the pond except ____?
A. Lablab B. Lumut C. Brown algae D. Rice bran

2. It is a collective term for microscopic organisms suspended in the water.

A. Lumut B. Plankton C. Phytoplankton D. Zooplankton

3. This is a filamentous green algae present in the ponds.

A. Lumut B. Plankton C. Zooplankton D. all of the above

4. Which of the following is the component of lablab in plants?

A. Blue green algae C. Green algae
B. Diatoms D. Detritus

30
5. It is a complex association of minute plants and animals forming a brownisg, greenish,
yellowish mat on the pond bottom and sometimes float on the pond surface as patches.
A. Plankton B. Lablab C. Lumut D. Rice bran

Additional activity

Activity Sheet 1.1

I. Directions: Answer the following questions

1. What are the different classes of natural food for fishes?Give two or more examples of
each class and show photos of each.
2. How are you going to grow the following natural foods- azolla, lemna, duckweed.
3. What is the difference between phytoplankton and zooplankton?
4. What is the difference between microphytes and macrophytes? Give two or more
examples of each type by showing photos.

Rubrics to be used in grading:

4  Explanation or answer demonstrtaes strong understanding of the concept
 Student completely explain the concept using appropriate vocabulary
3  Explanation demonstrates good understanding of the concept
 Explanation is nearly complete but some gaps exist; vocabulary is appropriate
2  Explanation demonstrates some understanding of concept
 Explanation is vague or inconsistent with missing or inappropriate vocabulary
1  Explanation demonstrates limited understanding of concept
 Minimal explanation is provided and explanation is unclear with missing and
inappropriate vocabulary
0  Student was unable to offer any explanation

Answer key

Self Check:
1. D
2. B
3. A
4. C
5. B

31
 References

Abella, T.A. Pag-aalagang Tilapia brochure. Freshwater Aquaculture Center, Central Luzon
State University, Nueva Ecija, Philippines

Bagarino, T. U. 1999. Ecology and Farming of Milkfish. Southeast Asian Fisheries

Development Center-Aquaculture Department, Iloilo, Philippines.

Baldo, R.D. (2017). Organic Aquaculture of Nile Tilapia In Skyponds of Ilocos Norte. Mariano
Marcos State University, College of Aquatic Sciences and Applied Technology. Pias Sur,
Currimao, Ilocos Norte.

Bangus Technical Committee. 2004. Lab-lab and how to produce in milkfish ponds.
PCARRD Technical Bull. Series No. 8-A:PCARRD, Los Banos, Laguna, Philippines.

Boyd, C.E. 1980. Water Quality in Warm Water Fish Ponds. Alabama Agriculture
Experimental Station, Auburn University, Auburn, Alabama.

http://lifeofplant.blogspot.com/2011/05/chlorohyceae.html?m=1

http://tolweb.org/Bacillariophyceae/125298

https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/cyanophyceae#:~
text=Cyanophyceae%20(blue%2Dgreen%20algae),%2C%20or%20septic%2Dtank%20odo
r.

Huet, M. 1970. Textbook of Fish Culture: Breeding and Cultivation of Fish. Fishing News
Books Ltd. 436pp.

Mair, G.C. and T.A. Abella (eds). 1997. Technoguide on the Production of Genetically Male
Tilapia (GMT). Freshwater Aquaculture Center (FAC), Central Luzon State University,
Nueva Ecija, Philippines.

Traditional Bangus Culture. 1995. Aqua Farm News Vol. XIII (No. 6). November-December
1995.

Saturno, J.O. Limnology Manual. College of Fisheries, Central Luzon State University,
Munoz, Nueva Ecija, Philippines.

32