Manual on the Production and Use of Live Food for Aquaculture
Sử dụng thức ăn tươi sống trong Nuôi trồng thủy sản (The success of any farming operation for fish and shellfish depends upon the availability of a ready supply of larvae or ‘seed’ for on-growing to market size. However, for many fish and shellfish species (i.e. carps, marine finfish, crustaceans, bivalves etc.) this has only been possible in recent years through the development and use of a succession of live food organisms as feed for the developing larvae. The aim of the present manual was therefore to review and summarise the latest developments concerning the production and use of the......
Manual on the Production and Use of Live
Food for Aquaculture
Table of Contents
FAO FISHERIES TECHNICAL PAPER
361
Edited by
Patrick Lavens and Patrick Sorgeloos
Laboratory of Aquaculture and Artemia Reference Center
University of Ghent
Ghent, Belgium
Food and Agriculture Organization of the United Nations
Rome, 1996
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imply the expression of any opinion whatsoever on the part of the Food and Agriculture
Organization of the United Nations concerning the legal status of any country, territory,
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boundaries.
M-44
ISBN 92-5-103934-8
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© FAO 1996
Table of Contents
PREPARATION OF THIS DOCUMENT
1. INTRODUCTION
2. MICRO-ALGAE
2.1. Introduction
2.2. Major classes and genera of cultured algal species
2.3. Algal production
2.3.1. Physical and chemical conditions
2.3.1.1. Culture medium/nutrients
2.3.1.2. Light
2.3.1.3. pH
2.3.1.4. Aeration/mixing
2.3.1.5. Temperature
2.3.1.6. Salinity
2.3.2. Growth dynamics
2.3.3. Isolating/obtaining and maintaining of cultures
2.3.4. Sources of contamination and water treatment
2.3.5. Algal culture techniques
2.3.5.1. Batch culture
2.3.5.2. Continuous culture
2.3.5.3. Semi-continuous culture
2.3.6. Algal production in outdoor ponds
2.3.7. Culture of sessile micro-algae
2.3.8. Quantifying algal biomass
2.3.9. Harvesting and preserving micro-algae
2.3.10. Algal production cost
2.4. Nutritional value of micro-algae
2.5. Use of micro-algae in aquaculture
2.5.1. Bivalve molluscs
2.5.2. Penaeid shrimp
2.5.3. Marine fish
2.6. Replacement diets for live algae
2.6.1. Preserved algae
2.6.2. Micro-encapsulated diets
2.6.3. Yeast-based diets
2.7. Literature of interest
2.8. Worksheets
Worksheet 2.1.: Isolation of pure algal strains by the agar plating technique
Worksheet 2.2.: Determination of cell concentrations using haematocytometer according
to Fuchs-Rosenthal and Burker.
Worksheet 2.3.: Cellular dry weight estimation of micro-algae.
3. ROTIFERS
3.1. Introduction
3.2. Morphology
3.3. Biology and life history
3.4. Strain differences
3.5. General culture conditions
3.5.1. Marine rotifers
3.5.1.1. Salinity
3.5.1.2. Temperature
3.5.1.3. Dissolved oxygen
3.5.1.4. pH
3.5.1.5. Ammonia (NH3)
3.5.1.6. Bacteria
3.5.1.7. Ciliates
3.5.2. Freshwater rotifers
3.5.3. Culture procedures
3.5.3.1. Stock culture of rotifers
3.5.3.2. Upscaling of stock cultures to starter cultures
3.5.3.3. Mass production on algae
3.5.3.4. Mass production on algae and yeast
3.5.3.5. Mass culture on yeast
3.5.3.6. Mass culture on formulated diets
3.5.3.7. High density rearing
3.5.4. Harvesting/concentration of rotifers
3.6. Nutritional value of cultured rotifers
3.6.1. Techniques for (n-3) HUFA enrichment
3.6.1.1. Algae
3.6.1.2. Formulated feeds
3.6.1.3. Oil emulsions
3.6.2. Techniques for vitamin C enrichment
3.6.3. Techniques for protein enrichment
3.6.4. Harvesting/concentration and cold storage of rotifers
3.7. Production and use of resting eggs
3.8. Literature of interest
3.9 Worksheets
Worksheet 3.1. Preparation of an indicator solution for determination of residual chlorine
4. ARTEMIA
4.1. Introduction, biology and ecology of Artemia
4.1.1. Introduction
4.1.2. Biology and ecology of Artemia
4.1.2.1. Morphology and life cycle
4.1.2.2. Ecology and natural distribution
4.1.2.3. Taxonomy
4.1.2.4. Strain-specific characteristics
4.1.3. Literature of interest
4.2. Use of cysts
4.2.1. Cyst biology
4.2.1.1. Cyst morphology
4.2.1.2. Physiology of the hatching process
4.2.1.3. Effect of environmental conditions on cyst metabolism
4.2.1.4. Diapause
4.2.2. Disinfection procedures
4.2.3 Decapsulation
4.2.4. Direct use of decapsulated cysts
4.2.5. Hatching
4.2.5.1. Hatching conditions and equipment
4.2.5.2. Hatching quality and evaluation
4.2.6. Literature of interest
4.2.7. Worksheets
Worksheet 4.2.1.: Procedure for estimating water content of Artemia cysts
Worksheet 4.2.2.: Specific diapause termination techniques
Worksheet 4.2.3.: Disinfection of Artemia cysts with liquid bleach
Worksheet 4.2.4.: Procedures for the decapsulation of Artemia cysts
Worksheet 4.2.5.: Titrimetric method for the determination of active chlorine in
hypochlorite solutions
Worksheet 4.2.6.: Artemia hatching
Worksheet 4.2.7.: Determination of hatching percentage, hatching efficiency and
hatching rate
4.3. Use of nauplii and meta-nauplii
4.3.1. Harvesting and distribution
4.3.2. Cold storage
4.3.3. Nutritional quality
4.3.4. Enrichment with nutrients
4.3.5. Enrichment for disease control
4.3.6. Applications of Artemia for feeding different species
4.3.6.1. Penaeid shrimp
4.3.6.2. Freshwater prawn
4.3.6.3. Marine fish
4.3.6.4. Freshwater fish
4.3.6.5. Aquarium fish
4.3.7. Literature of interest
4.3.8. Worksheets
Worksheet 4.3.1.: Standard enrichment for Great Salt Lake Artemia.
4.4. Tank production and use of ongrown Artemia
4.4.1. Nutritional properties of ongrown Artemia
4.4.2. Tank production
4.4.2.1. Advantages of tank production and tank produced biomass
4.4.2.2. Physico-chemical conditions
4.4.2.3. Artemia
4.4.2.4. Feeding
4.4.2.5. Infrastructure
4.4.2.6. Culture techniques
4.4.2.7. Enrichment of ongrown Artemia
4.4.2.8. Control of infections
4.4.2.9. Harvesting and processing techniques
4.4.2.10. Production figures and production costs
4.4.3. Literature of interest
4.4.4. Worksheets
Worksheet 4.4.1: Feeding strategy for intensive Artemia culture.
4.5. Pond production
4.5.1. Description of the different Artemia habitats
4.5.1.1. Natural lakes
4.5.1.2. Permanent solar salt operations
4.5.1.3. Seasonal units
4.5.2. Site selection
4.5.2.1. Climatology
4.5.2.2. Topography
4.5.2.3. Soil conditions
4.5.3. Pond adaptation
4.5.3.1. Large permanent salt operations
4.5.3.2. Small pond systems
4.5.4. Pond preparation
4.5.4.1. Liming
4.5.4.2. Predator control
4.5.4.3. Fertilization
4.5.5. Artemia inoculation
4.5.5.1. Artemia strain selection
4.5.5.2. Inoculation procedures
4.5.6. Monitoring and managing the culture system
4.5.6.1. Monitoring the Artemia population
4.5.6.2. Abiotic parameters influencing Artemia populations
4.5.6.3. Biotic factors influencing Artemia populations
4.5.7. Harvesting and processing techniques
4.5.7.1. Artemia biomass harvesting and processing
4.5.7.2. Artemia cyst harvesting and processing
4.5.8. Literature of interest
4.5.9. Worksheets
Worksheet 4.5.1.: Pond improvements and harvesting procedures
Worksheet 4.5.2.: Procedures for the brine processing step
Worksheet 4.5.3.: Procedures for the freshwater processing step
5. ZOOPLANKTON
5.1. Wild zooplankton
5.1.1. Introduction
5.1.2. Collection from the wild
5.1.3. Collection techniques
5.1.3.1. Plankton nets
5.1.3.2. Trawl nets
5.1.3.3. Baleen harvesting system
5.1.3.4. Flow-through harvesting
5.1.3.5. Plankton light trapping
5.1.4. Zooplankton grading
5.1.5. Transport and storage of collected zooplankton
5.2. Production of copepods
5.2.1. Introduction
5.2.2. Life cycle
5.2.3. Biometrics
5.2.4. Nutritional quality
5.2.5. Culture techniques
5.2.5.1. Calanoids
5.2.5.2. Harpacticoids
5.2.6. Use of resting eggs
5.2.7. Applications in larviculture
5.3. Mesocosm systems
5.3.1. Introduction
5.3.2. Types of mesocosms
5.3.2.1. Pold system (2-60 m³)
5.3.2.2. Bag system (50-200 m³)
5.3.2.3. Pond system
5.3.2.4. Tank system
5.3.3. Mesocosm protocol
5.3.4. Comparison to intensive methods
5.4. Literature of interest
6. CLADOCERANS, NEMATODES AND TROCHOPHORA LARVAE
6.1. Daphnia and Moina
6.1.1. Biology and life cycle of Daphnia
6.1.2. Nutritional value of Daphnia
6.1.3. Feeding and nutrition of Daphnia
6.1.4. Mass culture of Daphnia
6.1.4.1. General procedure for tank culture
6.1.4.2. Detrital system
6.1.4.3. Autotrophic system
6.1.4.4. General procedure for pond culture
6.1.4.5. Contamination
6.1.5. Production and use of resting eggs
6.1.6. Use of Moina
6.2. Nematodes
6.3. Trochophora larvae
6.3.1. Introduction
6.3.2. Production of trochophora larvae
6.3.2.1. Mussel larvae
6.3.2.2. Pacific oyster and Manila clam larvae
6.3.3. Quality control of the produced trochophora larvae
6.3.4. Cryopreservation
6.4. Literature of interest
BACK COVER
PREPARATION OF THIS DOCUMENT
The success of any farming operation for fish and shellfish depends upon the availability
of a ready supply of larvae or ‘seed’ for on-growing to market size. However, for many
fish and shellfish species (i.e. carps, marine finfish, crustaceans, bivalves etc.) this has
only been possible in recent years through the development and use of a succession of
live food organisms as feed for the developing larvae. The aim of the present manual was
therefore to review and summarise the latest developments concerning the production and
use of the major live food organisms currently employed in larviculture worldwide.
This document has been prepared within the framework of the aquaculture nutrition and
feed development activities of Dr. A.G.J. Tacon, Fishery Resources Officer, Inland Water
Resources and Aquaculture Service, FAO Fishery Resources Division, to help meet the
needs of aquaculture workers of Member Countries for the synthesis of information in the
field of aquaculture nutrition.
The editors would like to thank James de Caluwe, Rudi Bijnens, Magda Vanhooren and
March Verschraeghen for their assistance with the layout of the manual.
Lavens, P; Sorgeloos, P. (eds.)
Manual on the production and use of live food for aquaculture
FAO Fisheries Technical Paper. No. 361. Rome, FAO. 1996. 295p.
ABSTRACT
The cultivation of fish and shellfish larvae under controlled hatchery conditions requires
not only the development of specific culture techniques, but in most cases also the
production and use of live food organisms as feed for the developing larvae. The present
manual describes the major production techniques currently employed for the cultivation
of the major types of live food commonly used in larviculture, as well as their application
potential in terms of their nutritional and physical properties and feeding methods. The
manual is divided into different sections according to the major groups of live food
organisms used in aquaculture, namely micro-algae, rotifers, Artemia, natural zooplankton,
and copepods, nematodes and trochophores.
Distribution:
Directors of Fisheries and Aquaculture
FAO Regional Fishery Commissions and Working Groups on Aquaculture
FAO Fisheries Department
FAO Regional Fisheries Officers
FAO Aquaculture Projects
FAO Representatives
1. INTRODUCTION
Patrick Lavens and Patrick Sorgeloos
Laboratory of Aquaculture & Artemia Reference Center
University of Gent, Belgium
Whereas in the 1970s the production of farmed marine finfish and shrimp relied almost
exclusively on the capture of wild fry for subsequent stocking and on-growing in ponds,
tanks or cages, the complete domestication of many marine and brackishwater
aquaculture species was only achieved during the last two decades. However, since then
the controlled production of larvae from captive broodstock, or in other words the
hatchery production of fry, has now become a routine operation for most cultivated fish
and shellfish species; billions of fish and shellfish larvae (i.e. bivalve molluscs, penaeid
shrimp, salmonids, European seabass, Gilthead seabream etc.) currently being produced
within hatcheries all over the world.
The cultivation of larvae is generally carried out under controlled hatchery conditions and
usually requires specific culture techniques which are normally different from
conventional nursery and grow-out procedures, and especially with respect to husbandry
techniques, feeding strategies, and microbial control. The main reason for this is that the
developing larvae are usually very small, extremely fragile, and generally not
physiologically fully developed. For example, their small size (ie. small mouth size), the
uncompleted development of their perception organs (ie. eyes, chemoreceptors) and
digestive system, are limiting factors in proper feed selection and use during the early
first-feeding or start-feeding period. Moreover, in species such as shrimp, these are not
the only problems as the developing larvae also have to pass through different larval
stages, eventually changing from a herbivorous filter feeding behaviour to a carnivorous
hunting behaviour. It is perhaps not surprising therefore that larval nutrition, and in
particular that of the sensitive first-feeding larvae, has become one of the major
bottlenecks preventing the full commercialization of many farmed fish and shellfish
species. This can also be illustrated by the following examples.
· Larval/mouth size at first-feeding
The mouth size of first-feeding larvae usually mechanically restricts the size of the food
particles which can be ingested. In general, mouth size is correlated with body size,
which in turn is influenced by egg diameter and the period of endogenous feeding (ie.
yolk sac consumption period). For example, Atlantic salmon eggs are usually at least four
times larger than Gilthead seabream eggs (Table 1.1), and consequently on hatching yield
large salmon larvae with large yolk sac supplies (ie. sufficient endogenous feed reserves
for the first three weeks of their development), whereas first-feeding Gilthead seabream
larvae are very small with limited yolk sac reserves, and consequently can only feed
endogenously for about three days (Figures 1.1, 1.2 and 1.3). For example, at first-
feeding salmonid ‘alevins’ are able to consume feed particles as large as 1 mm, compared
with only 0.1 mm in the case of first-feeding Gilthead seabream larvae.
Table 1.1. Size of eggs and larval length at hatching in different fish species
(modified from Jones and Houde, 1981).
Species Egg diameter Length of larvae
(mm) (mm)
Atlantic salmon (Salmo salar) 5.0 - 6.0 15.0 - 25.0
Rainbow trout (Oncorhynchus mykiss) 4.0 12.0 - 20.0
Common carp (Cyprinus carpio) 0.9 - 1.6 4.8 - 6.2
European sea bass (Dicentrarchus labrax) 1.2 - 1.4 7.0 - 8.0
Gilthead seabream (Sparus aurata) 0.9 - 1.1 3.5 - 4.0
Turbot (Scophthalmus maximus) 0.9 - 1.2 2.7 - 3.0
Sole (Solea solea) 1.0 - 1.4 3.2 - 3.7
Milkfish (Chanos chanos) 1.1 - 1.25 3.2 - 3.4
Grey mullet (Mugil cephalus) 0.9 - 1.0 1.4 - 2.4
Greasy grouper (Epinephelus tauvina) 0.77 - 0.90 1.4 - 2.4
Bream (Acanthopagrus cuvieri) 0.78 - 0.84 1.8 - 2.0
Figure 1.1. Atlantic salmon larvae with yolk sac.
Figure 1.2. Gilthead seabream larva with yolk sac.
Figure 1.3. Atlantic salmon and gilthead seabream larvae at first feeding.
· Functional digestive tract
The developmental status of the digestive system of first-feeding larvae also dictates the
possibility or not of the larvae to digest the food ingested. For example, first-feeding
salmon alevins already have a well developed digestive tract with functioning enzyme
systems which allow the digestion of feed crumbles on first-feeding. By contrast,
Gilthead seabream larvae (like many other fish larvae; Figure 1.4) do not have a
functional stomach, but only a short digestive tract with only a few functional enzyme
systems at the onset of first-feeding. It follows therefore that these fish larvae will have to
rely on a food source that: 1) is at least partially and easily digestible (ie. the feed should
contain large amounts of free amino acids and oligopeptides instead of indigestible
complex protein molecules), 2) contains enzyme systems which allow autolysis (ie. self
destruction of the food particle), and 3) supplies in abundance all the essential nutrients
required by the larval predator.
Figure 1.4. Ontogenetic development of the digestive tract in cyprinid type fish (i.e.
common carp; modified from Dabrowski, 1984).
However, formulated feeds do not generally meet all these requirements and usually
result in poor growth and survival in small fish larvae such as the Gilthead seabream. On
the otherhand live food organisms seem to meet all the necessary criteria for these small
larvae. However, for food to be ingested by a larva it first has to be detected, and so the
degree of development of the functional sense organs such as the optical receptors (eyes),
chemoreceptors (olfactory organs, tastebuds) and mechanoreceptors (lateral line) is
crucial. For example, the eyes of fish larvae usually only contain cones in the retina
resulting in poor visibility, whereas the eyes of juvenile fish also contain rods with more
visual pigments in the retina. Moreover, live food organisms usually have a much better
contrast than artificial feeds and generally have a triggering effect by their continuous
movement, allowing an enhanced perception by the feeding larva. Similarly, the
swimming activity of live food organisms generally assures a good distribution of food
items in the water column, this in turn facilitating more frequent encounters with the
developing larvae which in most cases have a low mobility.
The aim of the present manual is to describe the various techniques employed for the
production and application of live food organisms as well as their application in
larviculture. The natural diet of most cultured fish and shellfish species consists of a wide
diversity of phytoplankton species (diatoms, flagellates, etc.) and zooplankton organisms
(copepods, cladocerans, decapod larvae, rotifers, ciliates, etc.), found in great abundance
in the natural plankton. This abundance and maximal diversity of food organisms of
different sizes and nutritional composition provide maximal chances for meeting all the
requirements of the predator larvae. Although the collection and/or production of natural
plankton for feeding in commercial hatcheries may therefore appear evident, in practice
the use of natural plankton often entails many constraints which will be explained in
detail in chapter 5. For the industrial larviculture of fish and shellfish, readily and
consistently available, practical and performing live diets need to be selected.
The selection of a suitable and nutritious diet should be based on a number of criteria
(Fig. 1.5.). Most of the criteria as identified from the viewpoint of the larva have already
been discussed above with the exception of the criterion ‘purity’. One should not only
consider the impurities by alien particles, but also the hygienic condition of the diet.
Contamination of live food with bacteria is not necessarily hazardous but may have a
tremendous impact on the microbial populations in the associated culture medium and
eventually in the fish/shrimp’s gut flora, and consequently on the health status and the
digestive capability of the larva (i.e. an impact that has only been fully realized in recent
years; see also chapters 3, 4.3 and 4.4).
Figure 1.5. Selection criteria for larval food sources from the viewpoint of the
culturist and the cultured larva (modified from Léger et al., 1987).
From the practical viewpoint of the culturist, a good diet should be readily available,
cost-effective, simple as well as versatile in application. The consistent availability of
sufficient quantities of food organisms is of the utmost importance in continuous hatchery
productions. In this respect, the collection and feeding of wild plankton has proven
unreliable and not always practical (see also chapter 5).
Over the past decades, trial and error approaches have resulted in the adoption of selected
larviculture diets, taking into account the different criteria listed in Fig. 1.5. Today, three
groups of live diets are widely applied in industrial larviculture of fish and shellfish:
· different species of 2 to 20 µm microalgae for:
bivalves
penaeid shrimp
rotifers, copepods,...
fish
· the 50 to 200 µm rotifer Brachionus plicatilis for:
crustaceans
marine fish
· the 400 to 800 µm brine shrimp Artemia spp. (meta-)nauplii for:
crustaceans
fish
Apart from these main groups, a few other live feeds are used on a more limited scale for
specific larviculture practices, including Brachionus rubens, Moina spp., daphnids, and
decapsulated brine shrimp cysts for freshwater fish and prawn larvae, and Artemia
biomass for lobster larvae, shrimp postlarvae and broodstock, and marine fish juveniles.
In recent years various formulations of supplementation and substitution products have
been added to this list although replacement diets are becoming more and more
successful in shrimp larviculture. However, their use in first-feeding marine fish is still
very limited.
Finally, a selection criterion that also needs to be addressed, especially at competitive
market prices of hatchery fry (for example, European seabass and gilthead seabream
prices have decreased by more than 50% over the last few years) is the larval feed cost,
which, depending on the species and culture technique applied, may account for up to
15% of the total production cost. Optimization of live food production and use in
hatcheries has therefore become even more important. This issue will also be further
elaborated in the different chapters of this manual.
Literature cited
Dabrowski, K., 1984. Ontogenetic development of cyprinid-like type of digestive tract.
Reprod. Nutr. Develop. 24: 807-819
Jones, A. and Houde E.D., 1981. Mass rearing of fish fry for aquaculture, p.351-374. In:
realism in aquaculture: achievements, constraints, perspectives. Bilio, M., Rosenthal, H.
and Sinderman, G.J. (eds). European Aquaculture Society, Bredene, Belgium, 585 p.
Leger, P., Bengston, D.A., Sorgeloos, P.,Simpson, K.L. and Beck, A.D., 1987. The
nutritional value of Artemia: a review, p. 357-372. In: Artemia research and its
applications. Vol. 3. Sorgeloos, P., Bengtson, D.A., Decleir, W., Jaspers, (eds). Universa
Press, Wetteren, Belgium, 556 p.
2. MICRO-ALGAE
2.1. Introduction
2.2. Major classes and genera of cultured algal species
2.3. Algal production
2.4. Nutritional value of micro-algae
2.5. Use of micro-algae in aquaculture
2.6. Replacement diets for live algae
2.7. Literature of interest
2.8. Worksheets
Peter Coutteau
aboratory of Aquaculture & Artemia Reference Center
University of Gent, Belgium
2.1. Introduction
Phytoplankton comprises the base of the food chain in the marine environment.
Therefore, micro-algae are indispensable in the commercial rearing of various species of
marine animals as a food source for all growth stages of bivalve molluscs, larval stages of
some crustacean species, and very early growth stages of some fish species. Algae are
furthermore used to produce mass quantities of zooplankton (rotifers, copepods, brine
shrimp) which serve in turn as food for larval and early-juvenile stages of crustaceans and
fish (Fig. 2.1.). Besides, for rearing marine fish larvae according to the “green water
technique” algae are used directly in the larval tanks, where they are believed to play a
role in stabilizing the water quality, nutrition of the larvae, and microbial control.
Figure 2.1. The central role of micro-algae in mariculture (Brown et al., 1989).
All algal species are not equally successful in supporting the growth and survival of a
particular filter-feeding animal. Suitable algal species have been selected on the basis of
their mass-culture potential, cell size, digestibility, and overall food value for the feeding
animal. Various techniques have been developed to grow these food species on a large
scale, ranging from less controlled extensive to monospecific intensive cultures.
However, the controlled production of micro-algae is a complex and expensive
procedure. A possible alternative to on-site algal culture is the collection of algae from
the natural environment where, under certain conditions, they may be extremely
abundant. Furthermore, in order to overcome or reduce the problems and limitations
associated with algal cultures, various investigators have attempted to replace algae using
artificial diets either as a supplement or as the main food source. These various aspects of
the production, use and substitution of micro-algae in aquaculture will be treated within
the limits of this chapter.
2.2. Major classes and genera of cultured
algal species
Today, more than 40 different species of micro-algae, isolated in different parts of the
world, are cultured as pure strains in intensive systems. Table 2.1. lists the eight major
classes and 32 genera of cultured algae currently used to feed different groups of
commercially important aquatic organisms. The list includes species of diatoms,
flagellated and chlorococcalean green algae, and filamentous blue-green algae, ranging in
size from a few micrometer to more than 100 µm. The most frequently used species in
commercial mariculture operations are the diatoms Skeletonema costatum, Thalassiosira
pseudonana, Chaetoceros gracilis, C. calcitrans, the flagellates Isochrysis galbana,
Tetraselmis suecica, Monochrysis lutheri and the chlorococcalean Chlorella spp. (Fig.
2.2.).
Figure 2.2. Some types of marine algae used as food in aquaculture (a) Tetraselmis
spp. (b) Dunaliella spp. (c) Chaetoceros spp. (Laing, 1991).
Table 2.1. Major classes and genera of micro-algae cultured in aquaculture
(modified from De Pauw and Persoone, 1988).
Class Genus Examples of application
Bacillariophyceae Skeletonema PL, BL, BP
Thalassiosira PL, BL, BP
Phaeodactylum PL, BL, BP, ML, BS
Chaetoceros PL, BL, BP, BS
Cylindrotheca PL
Bellerochea BP
Actinocyclus BP
Nitzchia BS
Cyclotella BS
Haptophyceae Isochrysis PL, BL, BP, ML, BS
Pseudoisochrysis BL, BP, ML
Dicrateria BP
Chrysophyceae Monochrysis (Pavlova) BL, BP, BS, MR
Prasinophyceae Tetraselmis (Platymonas) PL, BL, BP, AL, BS, MR
Pyramimonas BL, BP
Micromonas BP
Cryptophyceae Chroomonas BP
Cryptomonas BP
Rhodomonas BL, BP
Cryptophyceae Chlamydomonas Chlorococcum BL, BP, FZ, MR, BS BP
Xanthophyceae Olisthodiscus BP
Chlorophyceae Carteria BP
Dunaliella BP, BS, MR
Cyanophyceae Spirulina PL, BP, BS, MR
PL, penaeid shrimp larvae;
BL, bivalve mollusc larvae;
ML, freshwater prawn larvae;
BP, bivalve mollusc postlarvae;
AL, abalone larvae;
MR, marine rotifers (Brachionus);
BS, brine shrimp (Artemia);
SC, saltwater copepods;
FZ, freshwater zooplankton
2.3. Algal production
2.3.1. Physical and chemical conditions
2.3.2. Growth dynamics
2.3.3. Isolating/obtaining and maintaining of cultures
2.3.4. Sources of contamination and water treatment
2.3.5. Algal culture techniques
2.3.6. Algal production in outdoor ponds
2.3.7. Culture of sessile micro-algae
2.3.8. Quantifying algal biomass
2.3.9. Harvesting and preserving micro-algae
2.3.10. Algal production cost
2.3.1. Physical and chemical conditions
2.3.1.1. Culture medium/nutrients
2.3.1.2. Light
2.3.1.3. pH
2.3.1.4. Aeration/mixing
2.3.1.5. Temperature
2.3.1.6. Salinity
The most important parameters regulating algal growth are nutrient quantity and quality,
light, pH, turbulence, salinity and temperature. The most optimal parameters as well as
the tolerated ranges are species specific and a broad generalization for the most important
parameters is given in Table 2.2. Also, the various factors may be interdependent and a
parameter that is optimal for one set of conditions is not necessarily optimal for another.
2.3.1.1. Culture medium/nutrients
Concentrations of cells in phytoplankton cultures are generally higher than those found in
nature. Algal cultures must therefore be enriched with nutrients to make up for the
deficiencies in the seawater. Macronutrients include nitrate, phosphate (in an approximate
ratio of 6:1), and silicate.
Table 2.2. A generalized set of conditions for culturing micro-algae (modified from
Anonymous, 1991).
Parameters Range Optima
Temperature (°C) 16-27 18-24
Salinity (g.l-1) 12-40 20-24
Light intensity (lux) 1,000-10,000 2,500-5,000
(depends on volume and density)
Photoperiod (light: dark, hours) 16:8 (minimum)
24:0 (maximum)