The green water encouraged by the traditional carp farmers in the Far East and then Europe would be rich with live infusoria including cilates and freshwater rotifers for first feeding. The marine fish industry has had to look at marine rotifers and recreating the plankton soup as many larval species are too small to take newly hatched Artemia. The leading research labs using fish in medical and ecotoxicology projects that have relied upon lab-grown Paramecia cultures are revisiting rotifer culture to maximise fry survival rates.

1. T
he green water encouraged by the
traditional carp farmers in the Far
East and then Europe would be rich
with live infusoria including cilates
and freshwater rotifers for first feeding.
The marine fish industry has had to look at
marine rotifers and recreating the plankton
soup as many larval species are too small
to take newly hatched Artemia. The leading
research labs using fish in medical and
ecotoxicology projects that
have relied upon lab-grown
Paramecia cultures are
revisiting rotifer culture to
maximise fry survival rates.
Whilst attempts have
been made to replace live-
foods with artificial diets, the
protocol of co-feeding live
and processed diets cannot
be ignored. Through careful
enrichment, rotifers can be
used as a smart nutritional
package to aid the develop-
ment of gut bacteria, boost
health and support early lar-
val development.
Do your research and plan ahead
The Plankton Culture Manual by Frank
Hoff of Florida Aqua Farms is an invaluable
introduction to live food culture including
microalgae, rotifers, and Artemia culture. The
practical examples shown in this book are
based on the experience gained from the
creation and development of Instant Ocean
Hatcheries and operating a commercially
viable marine fish hatchery. The biggest mis-
take we have seen customers make is not
planning ahead and not having well-managed
cultures in place.
Where to get rotifers from
Live resting rotifer cysts are available to
establish cultures and can be shipped interna-
tionally by courier or airmail service. Two roti-
fer species are normally available: Brachionus
plicatilis (L-strain) for brackish-marine work
and Brachionus calyciflorus, used for freshwa-
ter cultures. The resting cysts are stored in
vials and may be frozen for long-term storage
and may be stored until you are ready to
inoculate a starter culture. The dehydrated
cysts will first need to hydrate in a Petri dish
before completing the incubation process and
hatching 48 plus hours later.
For the UK market we can supply live
B.plicatilis starter cultures at different salinities
for different applications.
The smaller marine S-strain Brachionus
rotundiformis is sometimes available for spe-
cialist projects where a smaller prey item is
required.
How to view rotifers
A basic binocular dissecting microscope
with at least 20x magnification is an essential
tool in managing rotifer cultures and even
monitoring the density of any live microalgae
present. Right from resting cysts to adult
rotifers the behaviour, feeding and breeding
condition of a culture can be observed. Once
the rotifer culture has been transferred to a
larger vessel, a simple torch can often be used
to illuminate and monitor culture densities.
Rotifer management
and harvesting
Under optimal conditions rotifer cultures
breed asexually with daughter cells produced.
FAF resting rotifer cysts being
hydrated for hatching
ZM live rotifers and live
microalgae
by Rohan Mak, ZM Systems
30 | INTERNATIONAL AQUAFEED | March-April 2015
FEATURE
They often evoke a love-hate relationship,
but you just can’t get away from them

2. The life cycle is normally 6-8 days; L-strain
rotifers are most prolific with a salinity at
22ppt and at optimal temperatures of 25
degrees Celsius. Only light aeration is normally
applied to avoid fast water movement that
may strip the daughter cells off the adult
rotifers.
Batch culturing rotifers in four to
five vessels has proved a straightforward
protocol and allows a culture to develop
over four to five days with one vessel
harvested each day. Normally two thirds
of a mature culture is harvested for feed-
ing and one third retained to establish
a new culture. This culture setup limits
water quality becoming an issue, the ves-
sels are cleaned between uses, and any
background build-up in ciliate populations
that may compromise the rotifers can be
kept in check.
Single vessel culture setups with pH,
ammonia control and biological filtration can
operate within a compact area, yield high
rotifer densities and allow daily harvesting.
Careful management of single vessel cultures
is still required to avoid ciliate population build
up and water parameters being exceeded
through laziness. This setup will represent ‘all
your eggs in one basket’ so your hatchery will
be at risk if the culture does crash and need
replacing.
Food options for rotifers:
Live microalgae have traditionally been
cultured for feeding and enriching rotifer
cultures. Starter cultures can be established
from microalgae plates that can be stored
in the fridge and shipped internationally by
courier. Normally Nannochloropsis and/or
Tetraselmis is used for a day-to-day rotifer
feed and Isochrysis used as a DHA enrich-
ment just prior to using the rotifers as a larval
feed. Microalgae culture technique remains
ZM live adult rotifer
and daughter cell
"Single vessel culture
setups with pH,
ammonia control and
biological filtration
can operate within a
compact area, yield
high rotifer densities and
allow daily harvesting"
March-April 2015 | INTERNATIONAL AQUAFEED | 31
FEATURE
© 2015 REED MARICULTURE, INC. ALL RIGHTS RESERVED. INSTANT ALGAE AND ENSURING HATCHERY SUCESS ARE TRADEMARKS OF REED MARICULTURE INC.
“Thanks to Reed Mariculture, the Totoaba is back on
track! Reed’s algae feeds allowed us to focus more on
larval rearing protocol development of the Totoaba,
and less on algae culture. Reed helped in every step,
providing custom adjustments to enrichments and
sharing live feed culture protocols.”
— Dr. Conal True, head of the Fish Culture Biotech Unit
at Autonomous University of Baja California
INSTANT ALGAE
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lture | 2015 Hatchery Ad Campaign | Theme: Ad-1 Conal True | Design: A | Version: 1 D A N I E
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Dr. True made it his life’s work to bring the totoaba–an endangered,
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Order InstantAlgae products to ensure repeatable production results.

3. a useful skill to know and may be applied
to other specialist livefood cultures including
copepods.
The use of marine algae concentrates and
prepared solutions have proved convenient
and have aided the design of high-density
rotifer rearing systems. The ability to cold-
store concentrates and feed by peristaltic
pump on a timer leads to regular feeding,
a more stable culture and a major labour-
saver.
The development of formulated dry yeast
invert feeds was the next progressive step
and these can be mixed daily and fed in the
same way as algae solutions. In their nature
prepared algae solutions have a lower per-
cent dry matter nutritional content, making it
easier for the new dry diets to offer a higher
contribution and cost savings.
INVE Aquaculture’s latest S.parkle prod-
uct is an evolution of the Culture Selco range
based on deactivated yeast. As a separate
development S.presso is the latest HUAF
emulsion/suspension enrichment product to
evolve from the Easy DHA Selco range and
now has protocols for both Artemia and
rotifers.
Harvesting rotifers:
Rotifers are normally harvested with
53-micron nylon mesh strainers,
smaller than the standard 120-micron
used for newly hatched Artemia. For
breeding projects requiring specifi-
cally small rotifers a 25-micron mesh
strainer can be used to grade out the
smallest individuals.
When harvesting rotifers it is
important to limit physical damage;
for example, when using a strainer
to harvest rotifers, aim to have
the mesh submerged as long as
possible. When siphoning a rotifer
culture from one tank to another,
limit the head difference so water
velocity is reduced.
Biosecurity:
Rotifers, like Artemia cysts, can
get everywhere and cross contami-
nate cultures including microalgae cultures if
you are not careful. Ideally rotifers and micro-
algae should be maintained in separate rooms
and staff should thoroughly wash and dry their
hands in between any maintenance work.
If you wish to be ultra-careful start the day
with water quality work on reservoir water
stocks, follow with microalgae work, and then
follow with live rotifer or copepod work with
hand-washing in between each session. When
working with both S-strain and L-strain rotifer
cultures cross contamination may be reduced
by running S-strain cultures at higher salinity
and temperatures to L-strain cultures.
www.zmsystems.co.uk
Providingproficienttoolstoachievecost-effectiveandsustainableaquaculturepractices
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Head Office and Orders: Jesús Aprendiz, 19. 1º A-B 28007 Madrid · SPAIN T. +34 915 014 041 · norel@norel.es · www.norel.es
Inve sparkle invert feed
ZM live rotifer sample in beaker
ZM live paramecia
32 | INTERNATIONAL AQUAFEED | March-April 2015
FEATURE

4. FAF microalgae disk and micro algae
grow F2 fertiliser
FAF plankton strainers for rotifer and
artemia collection
FAF rotifer cysts strainer
rotirich
ZM rotifer culture station
About the author
Rohan Mak has 27 years’ experience in aquaculture, aquatics, biotechnology, research holding sys-
tems, specialising in early feeding, live-food and microalgae culture. He trained at Sparsholt College,
Hampshire and the University of Plymouth for his M.Sc. in Applied Fish Biology. He was subsequently
employed at the University of Southampton on transgenic Nile tilapia and at Kings College, London
and University College, London on zebrafish for developmental biology and medical research studies.
ZM Systems are ZM fish-food and fishroom equipment UK distributors for INVE products includ-
ing Sep-Art Polarised Artemia, S.parkle, S.presso enrichments, Florida Aqua Farms microalgae culture
plates and fertilisers, resting rotifer cysts and the Plankton Culture Manual.
Their customers include developmental biology, biomedical and ecotoxicology research labora-
tories, government and commercial fish hatcheries and public aquaria.
In 2015 they are due to sponsor the first UK Artemia Workshop at the Plymouth Marine
Laboratory, currently being planned by John Rundle.
March-April 2015 | INTERNATIONAL AQUAFEED | 33
FEATURE
The International conference and trade show on Aquaculture,
World Aquaculture 2015, Jeju, Korea, will enhance industry
participation by incorporating the newly organized WA15
AquaForum.
The WA15 AquaForum has been created to benefit industry
professionals during the WA15 conference and exhibition. The
organizing committee invites Asian farmers, suppliers, and other
industry professionals to Jeju, Korea to attend this forum. Activi-
ties will include specific topical industry sessions, facilitated work-
shops, round table discussions, simultaneous translations, de-
signated meeting spaces, farm tours, etc. The focus of the WA15
AquaForum is targeted towards the most important industry
issues affecting key Asia Pacific aquaculture producing countries.
It is a true Industry forum whereby timely topical and regionally
relevant sessions are tailored to enhance industrial representation
and participation. Session topics will include Flatfish Health,
Shrimp Health, Aqua Feed technologies, Marine Finfish Technolo-
gies, Enhancing Shellfish Production and Integrated Aquaculture.
WAS aquaforum
2015
Updated information on: www.was.org
and Linked-in group‘World Aquaculture 2015 AquaForum’
World Aquaculture 2015
AquaForum
Jeju Island, Korea
May 26-29, 2015
VISIT US AT SEAFOOD EXPO GLOBAL
21-23 April 2015, Brussels, Belgium
Booth 4026 in Hall 9
GLOBALG.A.P. News Conference at
Seafood Expo Global in Brussels
22 April 2015, 2.30 - 3.30 p.m.
Hall 11, Room 1122, 3rd Floor
www.globalgap.org/events
WORKING TO IMPROVE THE
SUSTAINABILITY OF
COMPOUND FEED PRODUCTION
www.globalgap.org/cfm