• TABLE OF CONTENTS
HIDE
 Copyright
 Title Page
 Introduction
 Physical and chemical requirem...
 Food requirements
 Life cycles of Moina
 Nutritional value of Moina
 Procedure of Moina culture
 Additional points
 Sources of Moina






Group Title: Florida Cooperative Extension Service circular 1054
Title: Culture techniques of Moina
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00049211/00001
 Material Information
Title: Culture techniques of Moina the ideal Daphnia for feeding freshwater fish fry
Series Title: Circular
Physical Description: 5 p. : ill. ; 28 cm.
Language: English
Creator: Rottmann, R. W
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville
Publication Date: 1992
 Subjects
Subject: Moina   ( lcsh )
Daphnia   ( lcsh )
Freshwater fishes -- Feeding and feeds   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: R.W. Rottmann.
General Note: Title from cover.
General Note: "May 1992."
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00049211
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: oclc - 26320320

Table of Contents
    Copyright
        Copyright
    Title Page
        Page i
        Page ii
    Introduction
        Page 1
    Physical and chemical requirements
        Page 1
    Food requirements
        Page 1
    Life cycles of Moina
        Page 2
    Nutritional value of Moina
        Page 2
    Procedure of Moina culture
        Page 2
        Page 3
        Page 4
    Additional points
        Page 5
    Sources of Moina
        Page 5
        Page 6
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida




/0/

May 1992


Culture Techniques of Moina:

The Ideal Daphnia For

Feeding Freshwater Fish Fry


R.W. Rottmann

















Florida Cooperative Extension Service
Institute of Food and Agricultural Sciences
University of Florida
John T. Woeste, Dean


Circular 1054

























The information given herein is provided with the understanding that no discrimination is intended and
no endorsement by the University of Florida is implied. The listing of specific trade names or vendors does
not constitute an endorsement of these products or manufacturers in preference to others containing the
same ingredients or providing similar items.





i" '



W,".


R.W. Rottmann, Senior Biological Scientist, Fisheries and Aquaculture, IFAS, University of Florida.








Introduction
Daphnia are small freshwater crustaceans com-
monly called "water fleas". This common name
is the result not only of their size, but their short,
jerky hopping movement in water. The genera
Daphnia and Moina are closely related cladocerans.
They occur throughout the world and are collec-
tively known as daphnia.

Daphnia have a body consisting of a head and a
trunk (Figure 1). The antennae are the main means
of locomotion. Large compound eyes lie under the
skin on the sides of the head. One of the major
characteristic of daphnia is that the main part of
the body, the trunk, is enclosed in an external skel-
eton (carapace). Periodically, they molt or shed
their external shell. The brood pouch, where the
eggs and embryos develop, is on the dorsal side of
the female. In Daphnia, the brood pouch is com-
pletely closed, while Moina have an open pouch.


Figure 1. Adult Moina.


There is considerable size variation between
the genera. Moina are approximately half the
maximum length of Daphnia. Adult Moina (700
to 1,000 jm) are longer than newly-hatched brine
shrimp (500 pm) and approximately two to three
times the length of adult rotifers. Young Moina
(less than 400 gm), however, are smaller than
newly-hatched brine shrimp and approximately
the same size or slightly larger than adult rotifers.

As a result, Moina are ideally suited for feeding
freshwater fish fry. The newly-hatched fry of most
freshwater species can ingest young Moina as their
initial food. In addition, brine shrimp die quickly
in freshwater. In Singapore, Moina micrura grown
in ponds fertilized with mostly chicken manure or,
less frequently, with pig manure are used as the


sole food for fry of many ornamental tropical fish
species, with 95 to 99% survival to 3/4 inch (20 mm)
in length quite common. Unfortunately, there is
very little information concerning practical mass-
culture methods of Moina, and the available infor-
mation is in mimeograph documents, foreign jour-
nals, or other scarce publications.

Physical and chemical
requirements
Moina appear in high concentrations in pools,
ponds, lakes, ditches, slow-moving streams, and
swamps where organic material is decomposing.
They become especially abundant in temporary
water bodies which provide them with suitable
conditions for only a brief period. Moina are gener-
ally quite tolerant of poor water quality. They live
in water where the amount of dissolved oxygen
varies from almost zero to supersaturation. Moina
are particularly resistant to changes in the oxygen
concentration and often reproduce in large quanti-
ties in water bodies strongly polluted with sewage.
Species of Moina have been reported to play an
important role in the stabilization of sewage in
oxidation lagoons. The ability to survive in oxygen-
poor environments is due to their capacity to syn-
thesize hemoglobin. Hemoglobin formation is
dependent on the level of dissolved oxygen in the
water. The production of hemoglobin may also be
caused by high temperature and high population
density.

Moina are resistant to extremes in temperature
and easily withstand a daily variation of from 41
to 880F (5 31C); their optimum temperature is
75 to 880F (24 310C). The high temperature toler-
ance of Moina is of great advantage for both the
commercial fish farmers in the southern U.S. and
hobbyists culturing live food at home.

Food requirements
Moina feed on various groups of bacteria, yeast,
phytoplankton, and detritus (decaying organic mat-
ter). Bacterial and fungal cells rank high in food
value. Populations of Moina grow most rapidly
in the presence of adequate amounts of bacterial
and yeast cells as well as phytoplankton. Moina
are one of the few zooplankton which can utilize
the blue-green algae Microcystis aeruginosa. Both
plant and animal detritus may provide for the
growth and reproduction of Moina. The food value
of detritus depends on its origin and diminishes
with the age of the detritus.








Introduction
Daphnia are small freshwater crustaceans com-
monly called "water fleas". This common name
is the result not only of their size, but their short,
jerky hopping movement in water. The genera
Daphnia and Moina are closely related cladocerans.
They occur throughout the world and are collec-
tively known as daphnia.

Daphnia have a body consisting of a head and a
trunk (Figure 1). The antennae are the main means
of locomotion. Large compound eyes lie under the
skin on the sides of the head. One of the major
characteristic of daphnia is that the main part of
the body, the trunk, is enclosed in an external skel-
eton (carapace). Periodically, they molt or shed
their external shell. The brood pouch, where the
eggs and embryos develop, is on the dorsal side of
the female. In Daphnia, the brood pouch is com-
pletely closed, while Moina have an open pouch.


Figure 1. Adult Moina.


There is considerable size variation between
the genera. Moina are approximately half the
maximum length of Daphnia. Adult Moina (700
to 1,000 jm) are longer than newly-hatched brine
shrimp (500 pm) and approximately two to three
times the length of adult rotifers. Young Moina
(less than 400 gm), however, are smaller than
newly-hatched brine shrimp and approximately
the same size or slightly larger than adult rotifers.

As a result, Moina are ideally suited for feeding
freshwater fish fry. The newly-hatched fry of most
freshwater species can ingest young Moina as their
initial food. In addition, brine shrimp die quickly
in freshwater. In Singapore, Moina micrura grown
in ponds fertilized with mostly chicken manure or,
less frequently, with pig manure are used as the


sole food for fry of many ornamental tropical fish
species, with 95 to 99% survival to 3/4 inch (20 mm)
in length quite common. Unfortunately, there is
very little information concerning practical mass-
culture methods of Moina, and the available infor-
mation is in mimeograph documents, foreign jour-
nals, or other scarce publications.

Physical and chemical
requirements
Moina appear in high concentrations in pools,
ponds, lakes, ditches, slow-moving streams, and
swamps where organic material is decomposing.
They become especially abundant in temporary
water bodies which provide them with suitable
conditions for only a brief period. Moina are gener-
ally quite tolerant of poor water quality. They live
in water where the amount of dissolved oxygen
varies from almost zero to supersaturation. Moina
are particularly resistant to changes in the oxygen
concentration and often reproduce in large quanti-
ties in water bodies strongly polluted with sewage.
Species of Moina have been reported to play an
important role in the stabilization of sewage in
oxidation lagoons. The ability to survive in oxygen-
poor environments is due to their capacity to syn-
thesize hemoglobin. Hemoglobin formation is
dependent on the level of dissolved oxygen in the
water. The production of hemoglobin may also be
caused by high temperature and high population
density.

Moina are resistant to extremes in temperature
and easily withstand a daily variation of from 41
to 880F (5 31C); their optimum temperature is
75 to 880F (24 310C). The high temperature toler-
ance of Moina is of great advantage for both the
commercial fish farmers in the southern U.S. and
hobbyists culturing live food at home.

Food requirements
Moina feed on various groups of bacteria, yeast,
phytoplankton, and detritus (decaying organic mat-
ter). Bacterial and fungal cells rank high in food
value. Populations of Moina grow most rapidly
in the presence of adequate amounts of bacterial
and yeast cells as well as phytoplankton. Moina
are one of the few zooplankton which can utilize
the blue-green algae Microcystis aeruginosa. Both
plant and animal detritus may provide for the
growth and reproduction of Moina. The food value
of detritus depends on its origin and diminishes
with the age of the detritus.








Introduction
Daphnia are small freshwater crustaceans com-
monly called "water fleas". This common name
is the result not only of their size, but their short,
jerky hopping movement in water. The genera
Daphnia and Moina are closely related cladocerans.
They occur throughout the world and are collec-
tively known as daphnia.

Daphnia have a body consisting of a head and a
trunk (Figure 1). The antennae are the main means
of locomotion. Large compound eyes lie under the
skin on the sides of the head. One of the major
characteristic of daphnia is that the main part of
the body, the trunk, is enclosed in an external skel-
eton (carapace). Periodically, they molt or shed
their external shell. The brood pouch, where the
eggs and embryos develop, is on the dorsal side of
the female. In Daphnia, the brood pouch is com-
pletely closed, while Moina have an open pouch.


Figure 1. Adult Moina.


There is considerable size variation between
the genera. Moina are approximately half the
maximum length of Daphnia. Adult Moina (700
to 1,000 jm) are longer than newly-hatched brine
shrimp (500 pm) and approximately two to three
times the length of adult rotifers. Young Moina
(less than 400 gm), however, are smaller than
newly-hatched brine shrimp and approximately
the same size or slightly larger than adult rotifers.

As a result, Moina are ideally suited for feeding
freshwater fish fry. The newly-hatched fry of most
freshwater species can ingest young Moina as their
initial food. In addition, brine shrimp die quickly
in freshwater. In Singapore, Moina micrura grown
in ponds fertilized with mostly chicken manure or,
less frequently, with pig manure are used as the


sole food for fry of many ornamental tropical fish
species, with 95 to 99% survival to 3/4 inch (20 mm)
in length quite common. Unfortunately, there is
very little information concerning practical mass-
culture methods of Moina, and the available infor-
mation is in mimeograph documents, foreign jour-
nals, or other scarce publications.

Physical and chemical
requirements
Moina appear in high concentrations in pools,
ponds, lakes, ditches, slow-moving streams, and
swamps where organic material is decomposing.
They become especially abundant in temporary
water bodies which provide them with suitable
conditions for only a brief period. Moina are gener-
ally quite tolerant of poor water quality. They live
in water where the amount of dissolved oxygen
varies from almost zero to supersaturation. Moina
are particularly resistant to changes in the oxygen
concentration and often reproduce in large quanti-
ties in water bodies strongly polluted with sewage.
Species of Moina have been reported to play an
important role in the stabilization of sewage in
oxidation lagoons. The ability to survive in oxygen-
poor environments is due to their capacity to syn-
thesize hemoglobin. Hemoglobin formation is
dependent on the level of dissolved oxygen in the
water. The production of hemoglobin may also be
caused by high temperature and high population
density.

Moina are resistant to extremes in temperature
and easily withstand a daily variation of from 41
to 880F (5 31C); their optimum temperature is
75 to 880F (24 310C). The high temperature toler-
ance of Moina is of great advantage for both the
commercial fish farmers in the southern U.S. and
hobbyists culturing live food at home.

Food requirements
Moina feed on various groups of bacteria, yeast,
phytoplankton, and detritus (decaying organic mat-
ter). Bacterial and fungal cells rank high in food
value. Populations of Moina grow most rapidly
in the presence of adequate amounts of bacterial
and yeast cells as well as phytoplankton. Moina
are one of the few zooplankton which can utilize
the blue-green algae Microcystis aeruginosa. Both
plant and animal detritus may provide for the
growth and reproduction of Moina. The food value
of detritus depends on its origin and diminishes
with the age of the detritus.








Life cycles of Moina
The reproductive cycle of Moina has both a sexual
and asexual phase. Normally, the population con-
sists of all females that are reproducing asexually.
Under optimum conditions, Moina reproduce at only
4 to 7 days of age, with a brood size of 4 to 22 per
female. Broods are produced every 1.5 to 2.0 days,
with most females producing 2 to 6 broods during
their lifetime.

Under adverse environmental conditions, males
are produced and sexual reproduction occurs result-
ing in resting eggs (ephippia), similar to brine
shrimp eggs. The stimuli for the switch from
asexual to sexual reproduction in populations of
Moina is an abrupt reduction in the food supply,
resulting in an increase in resting egg production.
However, it is advantageous to keep the population
well fed and in the asexual mode of reproduction,
since fewer progeny are produced with resting eggs.

High population densities of Daphnia can result
in a dramatic decrease in reproduction, but this is
not apparently the case with Moina. The egg out-
put ofDaphnia magna drops sharply at a density
as low as 95 to 115 mature individuals per gallon
(25 30 / L). The maximum sustained density in
cultures of Daphnia reported is 1,900 individuals
per gallon (500 / L). Moina cultures, however,
routinely reach densities of 19,000 individuals
per gallon (5,000 / L) and are, therefore, better
adapted for intensive culture.

A comparison of the production of Daphnia
magna and Moina macrocopa cultures fertilized
with yeast and ammonium nitrate, showed that
the average daily yield of Moina (1.42 to 1.47 ounces
/ 100 gallons) (106 110 g/m3) is three to four times
the daily production of Daphnia (0.33 to 0.53 ounces
/ 100 gallons) (25 40 g/m3). Moina cultures fed
phytoplankton cultured on organic fertilizer has
been reported to exceed 5 ounces / 100 gallons
(375 g/m3) daily yield.

Nutritional value of Moina
The nutritional content of Moina varies consider-
ably depending on their age and the type of food
they are receiving. Although variable, the protein
content of Moina usually averages 50% of the dry
weight. Adults normally have a higher fat content


than juveniles. The total amount of fat per dry
weight is 20% to 27% for adult females and 4% to
6% for juveniles.

Procedure for Moina culture
The batch culture method of producing Moina
uses a continuous series of cultures. Briefly, a new
culture is started daily in a separate container us-
ing the procedures outlined below. When all the
fungal, bacterial, and algal cells are consumed,
usually about 5 to 10 days after inoculation, the
Moina are completely harvested, and the culture
is restarted. This method is particularly applicable
when a specific quantity of Moina is needed each
day, because daily production is much more con-
trolled. Batch culture is also useful for maintairing
pure cultures because there is less chance of the
cultures becoming contaminated with competitors
(e.g., protozoans, rotifers, copepods) or predators of
fish larvae or fry (e.g., Hydra, back-swimmers, div-
ing beetles, dragonfly larvae).

Semi-continuous cultures can be maintained for
two months or more by daily partial harvests of
Moina, water changes, and regular feeding, keeping
the population in a state of rapid growth. Eventu-
ally, the Moina cultures will fail to respond to addi-
tional fertilization. When it is evident that they
are not reproducing well, the Moina should be com-
pletely harvested and a new culture started. Moina
can be produced either in combination with their
food or as separate cultures. Combined culture is
the simplest, but production from separate cultures
has been reported to be approximately 1/3 higher.
For separate culture, the phytoplankton tank is
positioned so that it can be drained into the Moina
culture tank (Figure 2). Production from separate
cultures has the disadvantage of requiring addi-
tional space for the cultivation of phytoplankton.
Consequently, production per unit volume, espe-
cially in large scale cultures, is equivalent to when
the animals are grown together with their food.
However, there are advantages of separate culture
of Moina and phytoplankton such as: 1) less
chance of contamination; 2) greater degree of
control; and 3) more consistent yield.

Regardless of the culture method, always
maintain several Moina cultures to ensure a
supply in case of a die off.








Life cycles of Moina
The reproductive cycle of Moina has both a sexual
and asexual phase. Normally, the population con-
sists of all females that are reproducing asexually.
Under optimum conditions, Moina reproduce at only
4 to 7 days of age, with a brood size of 4 to 22 per
female. Broods are produced every 1.5 to 2.0 days,
with most females producing 2 to 6 broods during
their lifetime.

Under adverse environmental conditions, males
are produced and sexual reproduction occurs result-
ing in resting eggs (ephippia), similar to brine
shrimp eggs. The stimuli for the switch from
asexual to sexual reproduction in populations of
Moina is an abrupt reduction in the food supply,
resulting in an increase in resting egg production.
However, it is advantageous to keep the population
well fed and in the asexual mode of reproduction,
since fewer progeny are produced with resting eggs.

High population densities of Daphnia can result
in a dramatic decrease in reproduction, but this is
not apparently the case with Moina. The egg out-
put ofDaphnia magna drops sharply at a density
as low as 95 to 115 mature individuals per gallon
(25 30 / L). The maximum sustained density in
cultures of Daphnia reported is 1,900 individuals
per gallon (500 / L). Moina cultures, however,
routinely reach densities of 19,000 individuals
per gallon (5,000 / L) and are, therefore, better
adapted for intensive culture.

A comparison of the production of Daphnia
magna and Moina macrocopa cultures fertilized
with yeast and ammonium nitrate, showed that
the average daily yield of Moina (1.42 to 1.47 ounces
/ 100 gallons) (106 110 g/m3) is three to four times
the daily production of Daphnia (0.33 to 0.53 ounces
/ 100 gallons) (25 40 g/m3). Moina cultures fed
phytoplankton cultured on organic fertilizer has
been reported to exceed 5 ounces / 100 gallons
(375 g/m3) daily yield.

Nutritional value of Moina
The nutritional content of Moina varies consider-
ably depending on their age and the type of food
they are receiving. Although variable, the protein
content of Moina usually averages 50% of the dry
weight. Adults normally have a higher fat content


than juveniles. The total amount of fat per dry
weight is 20% to 27% for adult females and 4% to
6% for juveniles.

Procedure for Moina culture
The batch culture method of producing Moina
uses a continuous series of cultures. Briefly, a new
culture is started daily in a separate container us-
ing the procedures outlined below. When all the
fungal, bacterial, and algal cells are consumed,
usually about 5 to 10 days after inoculation, the
Moina are completely harvested, and the culture
is restarted. This method is particularly applicable
when a specific quantity of Moina is needed each
day, because daily production is much more con-
trolled. Batch culture is also useful for maintairing
pure cultures because there is less chance of the
cultures becoming contaminated with competitors
(e.g., protozoans, rotifers, copepods) or predators of
fish larvae or fry (e.g., Hydra, back-swimmers, div-
ing beetles, dragonfly larvae).

Semi-continuous cultures can be maintained for
two months or more by daily partial harvests of
Moina, water changes, and regular feeding, keeping
the population in a state of rapid growth. Eventu-
ally, the Moina cultures will fail to respond to addi-
tional fertilization. When it is evident that they
are not reproducing well, the Moina should be com-
pletely harvested and a new culture started. Moina
can be produced either in combination with their
food or as separate cultures. Combined culture is
the simplest, but production from separate cultures
has been reported to be approximately 1/3 higher.
For separate culture, the phytoplankton tank is
positioned so that it can be drained into the Moina
culture tank (Figure 2). Production from separate
cultures has the disadvantage of requiring addi-
tional space for the cultivation of phytoplankton.
Consequently, production per unit volume, espe-
cially in large scale cultures, is equivalent to when
the animals are grown together with their food.
However, there are advantages of separate culture
of Moina and phytoplankton such as: 1) less
chance of contamination; 2) greater degree of
control; and 3) more consistent yield.

Regardless of the culture method, always
maintain several Moina cultures to ensure a
supply in case of a die off.








Life cycles of Moina
The reproductive cycle of Moina has both a sexual
and asexual phase. Normally, the population con-
sists of all females that are reproducing asexually.
Under optimum conditions, Moina reproduce at only
4 to 7 days of age, with a brood size of 4 to 22 per
female. Broods are produced every 1.5 to 2.0 days,
with most females producing 2 to 6 broods during
their lifetime.

Under adverse environmental conditions, males
are produced and sexual reproduction occurs result-
ing in resting eggs (ephippia), similar to brine
shrimp eggs. The stimuli for the switch from
asexual to sexual reproduction in populations of
Moina is an abrupt reduction in the food supply,
resulting in an increase in resting egg production.
However, it is advantageous to keep the population
well fed and in the asexual mode of reproduction,
since fewer progeny are produced with resting eggs.

High population densities of Daphnia can result
in a dramatic decrease in reproduction, but this is
not apparently the case with Moina. The egg out-
put ofDaphnia magna drops sharply at a density
as low as 95 to 115 mature individuals per gallon
(25 30 / L). The maximum sustained density in
cultures of Daphnia reported is 1,900 individuals
per gallon (500 / L). Moina cultures, however,
routinely reach densities of 19,000 individuals
per gallon (5,000 / L) and are, therefore, better
adapted for intensive culture.

A comparison of the production of Daphnia
magna and Moina macrocopa cultures fertilized
with yeast and ammonium nitrate, showed that
the average daily yield of Moina (1.42 to 1.47 ounces
/ 100 gallons) (106 110 g/m3) is three to four times
the daily production of Daphnia (0.33 to 0.53 ounces
/ 100 gallons) (25 40 g/m3). Moina cultures fed
phytoplankton cultured on organic fertilizer has
been reported to exceed 5 ounces / 100 gallons
(375 g/m3) daily yield.

Nutritional value of Moina
The nutritional content of Moina varies consider-
ably depending on their age and the type of food
they are receiving. Although variable, the protein
content of Moina usually averages 50% of the dry
weight. Adults normally have a higher fat content


than juveniles. The total amount of fat per dry
weight is 20% to 27% for adult females and 4% to
6% for juveniles.

Procedure for Moina culture
The batch culture method of producing Moina
uses a continuous series of cultures. Briefly, a new
culture is started daily in a separate container us-
ing the procedures outlined below. When all the
fungal, bacterial, and algal cells are consumed,
usually about 5 to 10 days after inoculation, the
Moina are completely harvested, and the culture
is restarted. This method is particularly applicable
when a specific quantity of Moina is needed each
day, because daily production is much more con-
trolled. Batch culture is also useful for maintairing
pure cultures because there is less chance of the
cultures becoming contaminated with competitors
(e.g., protozoans, rotifers, copepods) or predators of
fish larvae or fry (e.g., Hydra, back-swimmers, div-
ing beetles, dragonfly larvae).

Semi-continuous cultures can be maintained for
two months or more by daily partial harvests of
Moina, water changes, and regular feeding, keeping
the population in a state of rapid growth. Eventu-
ally, the Moina cultures will fail to respond to addi-
tional fertilization. When it is evident that they
are not reproducing well, the Moina should be com-
pletely harvested and a new culture started. Moina
can be produced either in combination with their
food or as separate cultures. Combined culture is
the simplest, but production from separate cultures
has been reported to be approximately 1/3 higher.
For separate culture, the phytoplankton tank is
positioned so that it can be drained into the Moina
culture tank (Figure 2). Production from separate
cultures has the disadvantage of requiring addi-
tional space for the cultivation of phytoplankton.
Consequently, production per unit volume, espe-
cially in large scale cultures, is equivalent to when
the animals are grown together with their food.
However, there are advantages of separate culture
of Moina and phytoplankton such as: 1) less
chance of contamination; 2) greater degree of
control; and 3) more consistent yield.

Regardless of the culture method, always
maintain several Moina cultures to ensure a
supply in case of a die off.

























Figure 2. Tank arrangement for the separate culture of Moina
i and its food.

Containers
Cultures have been maintained in 10-gallon
(38-L) aquaria. However, this volume is usually
too small to yield enough Moina to satisfy demand.
Tanks or vats (concrete, stainless steel, plastic,
or fiberglass), and earthen ponds can be used.
Wading pools, plastic sinks, old bathtubs, discarded
refrigerator liners, and cattle watering troughs also
work well. Do not use unpainted metal containers
unless they are stainless steel.

Water depth should be no greater than 3 feet
(0.9 m). A maximum depth of 16 to 20 inches
(0.4 0.5 m) is probably optimum. The shallow
water depth allows good light penetration for pho-
tosynthesis by phytoplankton and provides a large
surface to volume ratio for oxygen diffusion.

Diffuse light or shade over 1/3 of the water
surface of the Moina culture container is recom-
mended. A greenhouse covered with shade cloth
(50-80% light reduction) is ideal. Outdoor cultures
should be protected from rain to help stabilize pro-
duction and screened to prevent entry of predacious
aquatic insects.

Containers to be used, whether aquaria, tanks,
vats, or ponds, need not be particularly clean.
However, filamentous algae and predators of fish
larvae or fry (e.g., Hydra, back-swimmers, diving
beetles, dragonfly larvae) can be especially trouble-
some in Moina cultures. Tanks can be disinfected
with a 30% solution of muriatic acid or by drying in
sunlight. Earthen ponds should be drained and
sun dried.


Algae tank


ia tank
-_ l Moina tank
--- 71


Water
Moina are extremely sensitive to pesticides, met-
als (e.g., copper and zinc, which may be prevalent
in municipal or well water), detergents, bleaches,
and other toxic materials in the water supply. In-
sure that toxins are not inadvertently introduced
into the culture container. Well water should be
aerated for at least two hours. Municipal water
should be aerated for at least two days to neutral-
ize the chlorine, or sodium thiosulfate or a commer-
cially available chlorine neutralizer can be added to
shorten this process. Natural spring water is ideal.
Rain water is also excellent for Moina cultures,
if it is collected from an area that does not have
excessive air pollution. Filtered lake or stream
water may also be used.

The optimum water temperature for Moina is
75 to 88F (24 310C). Moina continue to thrive
at temperatures in excess of 90F (32C) for short
periods. However, low temperatures reduce pro-
duction.

Aeration
Gentle aeration of the Moina pools oxygenates
the water, keeps food particles in suspension, and
increases phytoplankton production; this results in
an increase in the number of eggs per female, the
proportion of egg-bearing females in the population,
and the population density. A small trickle of fresh
water into the culture container may also improve
production of Moina. Only one or two aquarium air
lines are required in culture containers up to 400
gallons (1.5 m3). Extremely small bubbles should
be avoided; they can get trapped under the cara-
pace. This causes Moina to float at the surface,
eventually killing them.

Feeding or fertilizing
Listed below are some common fertilizer materi-
als and application rates. Try several of these cul-
ture medias to determine which works best in your
situation. The initial fertilization rates provided
are only a starting point and will probably need
to be adjusted depending on individual culture
conditions.

The following quantity of fertilizer materials
should be added initially for each 100 gallons
(379 L) of water. Additional feed or fertilizer,
approximately 50 to 100% of the initial amount,
should be added about 5 days later.








1. Yeast: 0.3 0.5 ounce (8.5 14.2 g) of baker's
yeast.
2. Yeast and mineral fertilizer: 0.3 0.5 ounce
(8.5 14.2 g) of yeast, and 0.5 ounce (14.2 g)
of ammonium nitrate.
3. Alfalfa, bran, and yeast: 1.5 ounces (42.5 g)
of alfalfa pellets or meal, 1.5 ounce (42.5 g)
of wheat or rice bran, and 0.3 ounces (8.5 g)
of yeast.
4. Cow manure or sewage sludge, bran, and yeast:
5 ounces (142 g) of dried manure or sewage
sludge, 1.5 ounces (42.5 g) of wheat or rice bran,
and 0.3 ounces (8.5 g) of yeast.
5. Cow manure or sewage sludge, cotton seed meal,
and yeast: Use 5 ounces (142 g) of dried manure
or sewage sludge, 1.5 ounce (42.5 g) of cotton
seed meal and 0.3 ounces (8.5 g) of yeast.
6. Horse or cow manure or sewage sludge: Com-
bine 20 ounces (567 g) of dried manure or sewage
sludge.
7. Chicken or hog manure: Combine 6 ounces
(170 g) of dried manure.

Organic fertilizers are usually preferred to min-
eral fertilizers because they provide bacterial and
fungal cells and detritus as well as phytoplankton
as food for the Moina. This variety of food items
more completely meets their nutritional needs, re-
sulting in maximum production. Mineral fertilizers
may be used alone; however, they work better in
earthen ponds than in tanks or vats.

Fresh manures are preferred because they are
richer in organic matter and bacteria. However,
some farm animals are given feed additives that
control fly larvae in their manure; these may in-
hibit the production of Moina. Although not abso-
lutely necessary, the manure is frequently dried
before use. Commercially available organic fertiliz-
ers such as dehydrated cow manure and sewage
sludge may be used for Moina cultures.

Although manure is widely used to culture
Moina, yeast, alfalfa, and bran are less objection-
able to use and work well. Activated yeast (baker's
yeast) is readily available from wholesale food
distributors in 2-pound (0.9-kg) bags. Bran and
alfalfa meal or pellets can be purchased in 50-
pound (22.7-kg) bags from livestock feed stores.

Coarse organic materials such as manure, sew-
age sludge, hay, bran, and oil seed meals are usu-
ally suspended in the water column in mesh bags.
Cheese cloth, burlap, muslin, nylon, or other rela-
tively loose weave fabrics may be used. Nylon and
other synthetic fabrics, however, do not deteriorate
in water as do cotton or burlap. For smaller culture


containers, nylon stockings work well for this pur-
pose: they are inexpensive, and readily available.
The use of a bag prevents large particles from being
a problem when the Moina are harvested and
allows greater control of fertilization.

Overfeeding can quickly cause problems in water
quality. Regardless of the type of media used, start
with small amounts of feed or fertilizer added at
frequent intervals; slowly increase the amount
used as you gain experience. If fungus occurs in
the culture container due to over-fertilization, the
bag containing the organic material should be
removed from the culture. If fungus persists in
large quantities, the culture should be discarded
and restarted.

Excessively high pH (greater than 9.5) due
to a heavy algae bloom and the resulting increase
in the proportion of the toxic form of ammonia
(un-ionized), may inhibit the production of Moina.
The pH of the culture can be adjusted to 7 to 8 with
vinegar (acetic acid).

Inoculating
Use pure live cultures to inoculate. Avoid using
animals for inoculation from poor or declining cul-
tures, cultures producing resting eggs, or cultures
containing predators of fish larvae or fry. Inoculate
with approximately 100 Moina / gallon (25 / L).
Although a culture can theoretically be started with
a single female, always use an adequate number to
develop a harvestable population quickly. If fewer
are used, the population in the culture will increase
more slowly, therefore, the initial quantity of fertil-
izer or food should be reduced to prevent overfeed-
ing. A greater number used for inoculation reduces
the time to harvesting and lessens the chance of
contamination by competitors. Cultures are usu-
ally inoculated 24 hours or more after fertilization.
However, when yeast is used, Moina can be added
to the culture after a few hours of aeration, assum-
ing good water quality and proper temperature.
This is because the yeast cells are immediately
available to the Moina as food. The small amount
of phytoplankton present in the water and digestive
tract of the Moina used to inoculated the culture
is usually sufficient to initiate a phytoplankton
bloom. Sometimes the mortality of the initial
inoculation is high and an additional inoculation
is required.

Monitoring
The culture should be inspected daily to deter-
mine its health. The following observations should
be made.









m The health of the culture is determined by stir-
ring the culture, removing 1 tablespoon (15 ml)
of the culture, and examining the sample with a
8X to 10X hand lens or dissecting scope. Green
or brown-red Moina with full intestinal tracts
and active movement indicate a healthy culture.
Pale Moina with empty digestive tracts or Moina
producing resting eggs are indications of sub-
optimum environmental conditions or insuffi-
cient food.

* The population density of Moina is determined
by killing the Moina in the sample with a 70%
alcohol solution and counting all Moina in a petri
dish with a hand lens or dissecting scope. Cul-
tures ready for harvest should contain 45 to 75
Moina in the 1-tablespoon sample (3 to 5/ml).
With experience, population density can be esti-
mated visually without the need for counts.

* The food concentration in the culture water,
when examined in a clear glass, should appear
slightly cloudy and tea colored or green. Clear
culture water is an indication of insufficient food.
The cultures should be fed or fertilized with
approximately 50-100% of the initial quantity
whenever the transparency is greater than about
12 to 16 inches (0.3 to 0.4 m). This can be deter-
mined with a white plastic or metal lid approxi-
mately 4 inches (100 mm) in diameter, attached
to the end of a yard stick. The depth of transpar-
ency is where the disk is just barely visible when
lowered into the tank.

* If predators of fish larvae or fry (e.g., Hydra,
back-swimmers, diving beetles, dragonfly larvae)
are observed, discard the culture and clean and
disinfect the tank or pool to avoid contaminating
other cultures.

Harvesting
Moina can be harvested by simply dipping out
the required number with a brine shrimp net or
re-usable coffee filter as they concentrate in "clouds"
at the surface. Cultures may also be harvested by
draining or siphoning the culture water into a
plankton collector equipped with 50 to 150-gm mesh
netting net suspended in a container of water. Turn
off the aeration and allow the food particles to settle
before harvesting. For semi-continuous culture, do
not harvest more than 1/5 to 1/4 of the population
each day, unless you are restarting the culture. Har-
vesting by draining the culture tank allows for a
partial water exchange, improving water quality.
Harvest only small quantities at a time and transfer
the Moina to containers with fresh water to keep
them alive.


The bottom sediments should be stirred up
manually every day following harvest, thoroughly
mixing the culture, to prevent anaerobic conditions
and re-suspend food particles.

Additional points
Differences in size, brood production, and opti-
mum environmental conditions exist between dif-
ferent species and varieties of Moina. Adjustments
will need to be made in the culture technique de-
pending on the particular species or variety you
wish to produce.

Additional surfaces in the culture tank may have
a positive effect on the production of Moina. For
Daphnia, a four-fold increase of surface area, in the
form of plastic sheets, has been shown to result in
a four-fold increase in the density, biomass, and
harvest. It is unknown whether this is the result
of improved water quality due to nitrifying bacteria
on the substrate, a change in the spatial distribu-
tion of the Daphnia, or improved nutrition.

It may not always be possible to match Moina
production to the food demand of the fish fry. Har-
vested Moina can be kept alive for several days in
clean water in a refrigerator. They will resume
normal activity when they are again warmed. The
nutritional quality of the stored Moina probably
will not be optimal because of the period of starva-
tion, so the Moina should be enriched with algae
and yeast before feeding them to fish. Moina can be
stored for long periods by freezing in low salinity
water (7 ppt, 1.0046 density) or by freeze-drying.
Both methods kill the Moina, so adequate circula-
tion is required to keep them in suspension after
thawing so they will be available to the fish fry.
Frozen and freeze-dried Moina are not as nutri-
tious as live animals, and they are not as readily
accepted by fish fry. Although freezing or freeze-
drying does not significantly alter the nutritional
content of Moina, nutrients do leach out rapidly
into the water. Nearly all of the enzyme activity is
lost within ten minutes after introduction in fresh
water. After one hour, all of the free amino acids
and many of the bound amino acids are lost.

Sources of Moina
Elwyn Segrest
Segrest Farms
P.O. Box 758
Gibsonton, FL 33534
(813) 677-9196









m The health of the culture is determined by stir-
ring the culture, removing 1 tablespoon (15 ml)
of the culture, and examining the sample with a
8X to 10X hand lens or dissecting scope. Green
or brown-red Moina with full intestinal tracts
and active movement indicate a healthy culture.
Pale Moina with empty digestive tracts or Moina
producing resting eggs are indications of sub-
optimum environmental conditions or insuffi-
cient food.

* The population density of Moina is determined
by killing the Moina in the sample with a 70%
alcohol solution and counting all Moina in a petri
dish with a hand lens or dissecting scope. Cul-
tures ready for harvest should contain 45 to 75
Moina in the 1-tablespoon sample (3 to 5/ml).
With experience, population density can be esti-
mated visually without the need for counts.

* The food concentration in the culture water,
when examined in a clear glass, should appear
slightly cloudy and tea colored or green. Clear
culture water is an indication of insufficient food.
The cultures should be fed or fertilized with
approximately 50-100% of the initial quantity
whenever the transparency is greater than about
12 to 16 inches (0.3 to 0.4 m). This can be deter-
mined with a white plastic or metal lid approxi-
mately 4 inches (100 mm) in diameter, attached
to the end of a yard stick. The depth of transpar-
ency is where the disk is just barely visible when
lowered into the tank.

* If predators of fish larvae or fry (e.g., Hydra,
back-swimmers, diving beetles, dragonfly larvae)
are observed, discard the culture and clean and
disinfect the tank or pool to avoid contaminating
other cultures.

Harvesting
Moina can be harvested by simply dipping out
the required number with a brine shrimp net or
re-usable coffee filter as they concentrate in "clouds"
at the surface. Cultures may also be harvested by
draining or siphoning the culture water into a
plankton collector equipped with 50 to 150-gm mesh
netting net suspended in a container of water. Turn
off the aeration and allow the food particles to settle
before harvesting. For semi-continuous culture, do
not harvest more than 1/5 to 1/4 of the population
each day, unless you are restarting the culture. Har-
vesting by draining the culture tank allows for a
partial water exchange, improving water quality.
Harvest only small quantities at a time and transfer
the Moina to containers with fresh water to keep
them alive.


The bottom sediments should be stirred up
manually every day following harvest, thoroughly
mixing the culture, to prevent anaerobic conditions
and re-suspend food particles.

Additional points
Differences in size, brood production, and opti-
mum environmental conditions exist between dif-
ferent species and varieties of Moina. Adjustments
will need to be made in the culture technique de-
pending on the particular species or variety you
wish to produce.

Additional surfaces in the culture tank may have
a positive effect on the production of Moina. For
Daphnia, a four-fold increase of surface area, in the
form of plastic sheets, has been shown to result in
a four-fold increase in the density, biomass, and
harvest. It is unknown whether this is the result
of improved water quality due to nitrifying bacteria
on the substrate, a change in the spatial distribu-
tion of the Daphnia, or improved nutrition.

It may not always be possible to match Moina
production to the food demand of the fish fry. Har-
vested Moina can be kept alive for several days in
clean water in a refrigerator. They will resume
normal activity when they are again warmed. The
nutritional quality of the stored Moina probably
will not be optimal because of the period of starva-
tion, so the Moina should be enriched with algae
and yeast before feeding them to fish. Moina can be
stored for long periods by freezing in low salinity
water (7 ppt, 1.0046 density) or by freeze-drying.
Both methods kill the Moina, so adequate circula-
tion is required to keep them in suspension after
thawing so they will be available to the fish fry.
Frozen and freeze-dried Moina are not as nutri-
tious as live animals, and they are not as readily
accepted by fish fry. Although freezing or freeze-
drying does not significantly alter the nutritional
content of Moina, nutrients do leach out rapidly
into the water. Nearly all of the enzyme activity is
lost within ten minutes after introduction in fresh
water. After one hour, all of the free amino acids
and many of the bound amino acids are lost.

Sources of Moina
Elwyn Segrest
Segrest Farms
P.O. Box 758
Gibsonton, FL 33534
(813) 677-9196


















































































COOPERATIVE EXTENSION SERVICE, UNIVERSITYOF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES, John T. Woeste,
Director, in cooperation with the United States Department of Agriculture, publishes this information to further the purpose of the May 8 and June
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this publication, editors should contact this address to determine availability. Printed 5/92.




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