Hydrobiologia 204/205 : 435-443, 1990 .S. C. Lindstrom and P. W. Gabrielson (eds), Thirteenth International Seaweed Symposium .

435© 1990 Kluwer Academic Publishers. Printed in Belgium .

Recent progress in the use of processed microalgae in aquaculture

T. R. Sommer', W . T. Potts' & N . M . Morrissy 2'Western Biotechnology, 2-6 Railway Parade, Bayswater, WA 6053 Australia ; 2Department of Fisheriesand Wildlife, Western Australian Marine Fisheries Laboratories, P .O. Box 20, North Beach, WA 6020Australia

Key words: aquaculture, astaxanthin, beta-carotene, processed microalgae

Abstract

Mass-cultured algal biomass has been tested as a food source for a number of aquaculture animalsbecause of its low cost and convenience. This paper reviews the results of nutritional studies on processedmicroalgae with respect to mollusc, crustacean, rotifer and fish culture . Research using species ofSpirulina, Chlorella, Scenedesmus and other mass-produced algae indicates that microalgae can be aneffective dietary component provided that processing, diet formulation and presentation requirements aremet. Processed microalgae can be used to correct specific dietary deficiencies in artificial diets . Ourresearch found that the growth and pigmentation of marron, Cherax tenuimanus (Decapoda, Crustacea),can be significantly enhanced by the incorporation of Dunaliella salina in its artificial diet . Likewise,rainbow trout, Oncorhynchus mykiss, were pigmented by Haematococcus pluvialis .

Introduction

The past two decades have seen the rapid ex-pansion of aquaculture, with significant researchand commercial activity in the areas of fish,mollusc and crustacean culture. Hatchery pro-duction has been identified as a major bottleneckto many aquaculture processes, as larval foodcultivation is expensive, and a nutritionallybalanced diet may be difficult to achieve (DePauw et al., 1984). For example, De Pauw et al.(1983) calculated that the cost of algal productionwhen suitable natural blooms are available isUS$4-23/kg dry wt, depending on the season .However, such blooms often are unreliable andoccasionally toxic (Becker, 1986 ; Holliday, 1986),so monoculture systems producing biomass forUS$120-200/kg dry wt often are preferred (DePauw et al., 1983) .

Parallel to the development of animal aquacul-ture has been microalgal mass cultivation, pri-marily for the health food market . Methods usedfor such processes are described in detail inBorowitzka & Borowitzka (1988) and Richmond(1986). Comparison of the economics of algalmass culture versus algal hatchery rearing revealsthat large scale pond production is much lessexpensive ; cost estimates range from $1 .5/kg forScenedesmus (De Pauw et al ., 1984) to $9/kg forChlorella (Soong, 1980) .

While it is clear that utilization of mass culturetechnology to supply low-cost biomass to aqua-culturists is feasible, the question remains as towhether processed algae are suitable for use . Thispaper will review some of the literature on the useof mass-cultured microalgae in animal aquacul-ture and describe some of the recent develop-ments in the field. The discussion will be confined

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largely to examples in which processed algae havebeen used in feeding studies. Descriptions of pro-cessing methods used for microalgae may befound in Mohn (1980, 1988) . Studies in whichalgae are grown in medum to large-scale vessels,then fed directly to aquaculture animals, will notbe covered here; these studies were reviewed indetail by De Pauw et al . (1983). Examples ofgenera that will be discussed are Spirulina,Chlorella and Scenedesmus, all of which have beenstudied intensively with respect to culture andprocessing .

Molluscan culture

Feeding trials with processed microalgae havefocused primarily on the use of either spray-driedor freeze-dried preparations . Hidu & Ukeles(1962) described some of the earliest research inwhich spray-dried Scenedesmus obliquus wassupplied either as whole or homogenized cells tolarvae of the clam Mercenaria mercenaria . Homo-genized cells resulted in the best larval growth,although not as rapid as a live mixture of flagellatealgal species . The authors also tested freeze-driedversus fresh Dunaliella euchlora and Isochrysis gal-bana with comparable growth and survival . At-tempts to optimize the feeding level resulted inlittle or no improvement . In a later study, Masson(1977) investigated the use of a variety of inertmaterials for the culture of Mytilusgalloprovincialisand found that Spirulina sp. was a reasonablefood source for larvae . In contrast, Walne (1979)reported that spray-dried Chlorella sp ., vacuum-dried Monochrysis lutheri, and freeze-dried Iso-chrysis galbana did not support significant growthof oyster larvae (Ostrea edulis) .

Although dried algae appeared nutritionally ac-ceptable to clams and mussels, a major problemwith inert diets is that they tend to agglutinate,making them difficult to keep in suspension andresulting in bacterial accumulation ; moreover,particle size is critically important (Masson,1977 ; Chanley & Normandin, 1967) . These diffi-culties may be resolved partially through the useof micronization, efficient mixing and bacterio-

cides (Hidu & Ukeles, 1962) . It also has beenproposed that product stability could be greatlyenhanced through the use of microencapsulation(Masson, 1977), which might also be used toimprove the suspension characteristics of suchpowders . Another suggestion is minimizing bacte-rial growth by providing axenic, highly purifiedpowders, and at least one company is pursuingthis technology with Tetraselmis sp ., Nannochlorissp. and Chlorella sp. (B. Kirsop, pers. comm.) .

An alternative to the use of dried feeds is to usefresh or wet formulations . Holliday (1986) de-scribed the use of the `Wells Glancy' algal culturetechnique in clam hatcheries in the U .S . Naturalassemblages of algae are induced to bloom inlarge tanks using fertilizers, centrifuged and heldfor up to one month as a concentrate in plasticbags. Such material also can be frozen orlyophilized to increase shelf life . Masson (1977)demonstrated that preserved Monochrysis lutheri,Tetraselmis suecica and Chlorella sp. were equiva-lent to living algae for Mytilus galloprovincialis .

One novel use for microalgae and their extractsin mollusc cultivation was discovered by Morseet al . (1984), who found that abalone larvae(Haliotis rufescens) were induced to settle usingextracts from Spirulina platensis and Synechococ-cus spp .

Rotifers

The rotifer, Branchionus plicatilis, is commonlycultured on marine Chlorella sp., then used as afeed for aquatic animals, usually larval fishes .Both commercial spray-dried Chlorella and yeasthave been tested as substitutes for fresh biomass,with better results obtained with the microalga .However, spray-dried Chlorella sp ., Scenedesmussp. and Spirulina maxima have not been as effec-tive a sole food source as live microalgae in spiteof attempts to optimize feeding levels in batchculture (Person-Le Ruyet, 1975 ; Hirayama &Nakamura, 1979) . Gatesoupe & Robin (1981)confirmed that dried Chlorella sp. and Spirulinasp. could sustain reasonable production and sur-vival of rotifers, but food conversion was generally

low and other factors such as particle size andenvironmental conditions were critical . Hygieneproblems appeared to be minimal or absent usingthe continuous system employed, provided thatan optimum feeding regime was followed .

These studies indicated that there was somenutritional deficiency in the spray-dried micro-algae. Gatesoupe & Robin (1981) attempted tocorrect this deficiency by producing formulateddiets with a high percentage of microalgae . Dietscontaining 40 % Spirulina sp. and yeast resulted inmarkedly improved food conversion . The authorsalso briefly examined the effect of supplementingdiets with freeze-dried microalgae, which arelikely to contain more of the unstable nutritionalcomponents than spray-dried material . However,addition of freeze-dried Platymonas suecica didnot enhance the performance of formulated dietscontaining spray-dried algae . Further research onthe optimum level of freeze-dried algal supple-ment indicated that prepared diets could result inhigher food conversion than fresh algae(Gatesoupe & Luquet, 1981) .

Ben-Amotz & Rosenthal (1981) tested cryo-preservation in greater detail with respect to opti-mal freezing conditions and nutritional value torotifers . Ten species including Chlorella sp .,Dunaliella salina, Nannochloris sp., Phaeodactylumtricornum and Platymonas suecica were studied .Cryopreserved biomass was found to be equiva-lent to live cells for rotifer growth, provided thatthe majority of the algal cells were still viable .

It should be noted that while micro algae may beused successfully as a feed for rotifers, the finalnutritional value of the rotifers to fish is of majorimportance. Changes in the nutritional com-ponents of the algal biomass as a result of pro-cessing using different species may not limit rotifergrowth, but may directly influence their dietaryvalue to fish larvae (Watanabe et al., 1983 ; Scott& Middleton, 1979) . Work by Gatesoupe &Luquet (1981) demonstrated that such de-ficiencies could be corrected through enrichmentwith products such as fish extracts and vitamins .

Crustaceans

Artemia

Like rotifers, brine shrimp are cultivated primarilyas a source of feed for larval aquatic animals .Although many species will accept freshlyhatched, unfed Artemia nauplii, supplementalfeeding of the Artemia with algae, yeast, rice branor formulated diets is necessary for continuousculture and for the production of a variety of preysizes .

Early attempts to substitute heat processedalgae (Phaeodactylum tricornum) for fresh biomassmet with no success (Takano, 1967) ; however,frozen forms of Dunaliella sp. (Sorgeloos, 1973)and Tetraselmis suecica (Person-Le Ruyet, 1975)later were found to support good growth and sur-vival in high density culture . Scenedesmus sp .powder also was shown to be acceptable becausethe drum-drying process caused disruption of thealgal cell wall, rendering it more digestible to brineshrimp (Sorgeloos, 1974) .

Other studies have confirmed the feasibiilty ofusing dried algae, but Spirulina sp. appears to bethe preferred species . Person-Le Ruyet (1975,1976) found dried Scenedesmus sp. to be less suit-able than Spirulina sp., perhaps as a result of thedifficulty in reducing it into a fine particle size .The use of Spirulina sp. was most efficient whenlarval densities for different age classes were ad-justed relative to feed supply in semi-continuousculture. In this manner production was optimized,growth rates were close to maximum levels, andno hygienic problems were observed (Person-LeRuyet, 1976) .

Johnson (1980) pursued the use of Spirulina sp .further in small-scale and mass-culture systems .In short-term comparisons, Spirulina sp . wasfound to be less effective than yeast (Rhodotorulasp.) or rice bran, but slightly better than freshDunaliella tertiolecta . Longer-term trials showedthat Spirulina sp . was superior nutritionally to allof the diets tested ; the larger particle size of thepowder may explain its poorer performance withyoung Artemia, whereas high protein and lipidlevels appeared to be a key factor in larger

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animals . The superiority of dried microalgaeagain was confirmed in intensive raceway sys-tems. As in the study by Person-Le Ruyet (1976),fouling of the system with excess food was not aproblem .

Shrimp and Prawns

Relatively little information is available on the useof processed microalgae with other crustaceans .Lim et al . (1978, 1979) compared spray-driedSpirulina sp. powder, casein, shrimp meal andsquid meal as a protein source for postlarvalprawns, Penaeus monodon . The algal treatmentresulted in the poorest weight gain and proteinefficiency ratio (PER) of all of the diets . However,Spirulina sp. was added at a very high level (82of ration) and the trials were very short induration. In contrast, Soong (1980) reported thatSpirulina sp. powder is an excellent source of foodfor shrimp larvae .

Tanaka (1978) briefly tested diets containingSpirulina supplements (10%) as a source ofpigment for the tiger prawn Penaeus japonicus . Heconcluded that prawns grown on algal powderhad more intense coloration and higher pigmentlevels than those fed corn, alfalfa or canthaxan-thin. Results from Tanaka et al. (1976) also con-firm that Spirulina sp. is an effective source ofprawn pigmentation .

Sun-drying has been tried as an alternative tospray-drying for other algal species . The bestprawn survival has been obtained with Chae-toceros calcitrans, followed by Tetraselmis chuii

and Isochrysis sp., respectively as sole foodsources (Millamena & Aujero, 1978) .

Frozen concentrates of fresh algae are em-ployed by some shrimp culturists using a modifiedversion of the Wells Glancy technique describedfor molluscs (Holliday, 1986) . In the Galvestontechnique, microalgal cultures are harvested viacentrifugation, mixed with cryoprotective agents,then frozen in concentrated form until thawed foruse with prawn larvae (Fox, 1983 ; Liao et al.,1983). Studies using frozen concentrate with lar-val prawns indicate that this method is as good as

or better than freeze drying (Brown, 1972),although unprocessed algae still are preferredgenerally (Griffith et al., 1973). Some problemswith clumping of thawed algal cells have beennoted (Mock et al., 1980). Species tested in frozenform include Thalassiosira sp., Skeletonema costa-tum (Brown, 1972 ; Mock et al., 1980),Chaetoceros calcitrans and Tetraselmis chuii (Mil-lamena & Aujero, 1978) .

Fish culture

Cyprinids

The nutritional value of processed algae to fishhas been studied best in carp, particularlyCyprinus carpio . Meske & Pfeffer (1977) providedinitial information on the use of dried Scenedes-

mus, yeast and casein in feeds, but found a fishmeal-based trout feed to be superior in mostrespects. Continued studies on mirror carp re-vealed that drum-dried Scenedesmus sp., troutfeeds and curd were not suitable substitutes forArtemia for carp fry . While young grass carp(Ctenopharyngodon idella) and mirror carp (Cy-prinus carpio) showed poor growth and defor-mities when using pure algal or fish meal, formu-lated diets containing optimal algal levels of 80(grass carp) and 50% (mirror carp) resulted inexcellent weight gain . Moreover, algal-fed mirrorcarp had higher protein efficiency ratios (PER),similar protein levels and lower fat levels thangroups fed a variety of trout feeds (Meske &Pfeffer, 1978) .

Similar studies also have been attempted usinglow-cost algal biomass produced in wastewaterponds . Algal diets were found to be readilyaccepted by mirror carp, although the digestibilityof flocculated, drum-dried algae was considerablylower than fish meal . Digestibility of Ankistrodes-mus sp. and Scenedesmus sp. cells was improvedslightly when the biomass was drum-dried ratherthan sun-dried (Sandbank & Hepher, 1978,1980). Poor digestibility of intact cells mayaccount, at least partially, for the inferior growthrates of grass carp on pond-grown Spirogyra sp .

(Stanley & Jones, 1976) . In spite of the lowerdigestibility of algal biomass, Sandbank &Hepher (1978, 1980) found that microalgae couldreplace much of the fish meal protein in processedfeeds with equal or superior results .

It is of interest that aluminum-based flocculantdid not adversely affect carp growth, nor did itsignificantly accumulate in the flesh (Sandbank &Hepher, 1978). These results are consistent withYannai et al. (1980), who found that carp fedwastewater grown algae (Chlorella) sp. did notappreciably accumulate heavy metals, in spite ofhigh levels in feed .

The apparent value of algal biomass in carpfeeds, however, must be considered relative to anumber of other possible protein sources. Atacket al. (1979) reported that ingredients such ascasein and bacterial and yeast protein resulted inbetter specific growth rates, food conversion andprotein efficiency ratios than Spirulina maximameal. Nevertheless, algal biomass may be of morebenefit than other components with respect topigmentation. Matsuno et al. (1979) described theuse of Spirulina sp. to intensify the color ofornamental carp (koi) ; spray-dried material hasbeen used extensively by commercial growers forthis purpose.

Tilapia

Variable results have been obtained using pro-cessed microalgae in Tilapia feeds . Stanley &Jones (1976) described positive results in trialsusing Spirulina sp. as a sole food source forTilapia aurea . Moreover, the benefits of Spirulinasp. were best when used as a fresh concentraterather than as a dried meal for Tilapia aurea(Soong, 1980) . But studies on Tilapia nilotica byKesamaru & Miyazono (1978a, 1978b) showedSpirulina platensis to be inferior to fish meal andwheat germ . These differences may be intraspeci-fic or due to processing conditions .Mixed species harvested from wastewater

ponds also have been tested on Tilapia galilea byShelef et al. (1980), with equivalent or superiorresults to fish meal-based feeds using rations

containing 22% dried algal biomass . Dickson(1987) found that algae cultivated on effluent froma fish farm were similar to other vegetable sourcesfor Tilapia (Oreochromis aureus), but that animalproteins were preferred . However, cultivationconditions were sub-optimal and the spray-driedalgal powder had low protein and high silt levels .Like carp, Tilapia coloration may benefit greatlyfrom Spirulina sp. supplements as carotenoids(e.g. zeaxanthin), contained within the alga, areused as a pigment source (Matsuno et al., 1980) .

Trout

Culture of trout and other salmonids requires theinclusion of high percentages of generally expen-sive animal protein ingredients such as fish meal .Although algal biomass such as Spirulina sp. i shigh in protein, it does not appear to be a satisfac-tory alternative . Matty & Smith (1978) showedthat formulated diets containing dried Spirulinamaxima resulted in poor weight gain, low foodconversion efficiencies and low protein efficiencyratios when compared to commercial feeds ordiets containing yeast or bacteria . This conclusionwas confirmed by Atack & Matty (1978),although digestibility was satisfactory . Spirulinasp . also has little or no benefit as a pigmentingagent as it has been observed to cause no detect-able carotenoid deposition in the flesh and resultsin a less desirable yellow-brown color (Choubert,1979) .

Other fish species

Processed microalgae have been tested at leastbriefly on a number of other aquaculture species,although few in any depth . Bigmouth buffalo(Ictiobus cyprinellus), when given fresh, concen-trated, pure Spirulina, had good growth and highfeed-conversion efficiencies (2 .0) (Stanley &Jones, 1976) . Soong (1980) indicated thatSpirulina was an excellent food source for variousage-classes of milkfish (Chanos chanos) . The useof algae produced in wastewater ponds as a feed

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for channel catfish (Ictalurus punctatus) also hasbeen examined by Reed et al. (1974) .

Recent progress

Research to date has focused largely on the use ofprocessed algae as a single or major componentof aquaculture diets . However, considerable po-tential exists to use microalgae to fulfil specificnutritional requirements . In addition, the range ofspecies studied in processed form remains fairlylimited. We describe here two examples in whichnovel species of microalgae are used to addressknown nutritional deficiencies .

Marron

Attempts to develop a complete ration for themarron (Cherax tenuimanus), an Australian fresh-water crayfish, have met with little success asgrowth rates and pigmentation have been sub-standard using even the most advanced diets(Morrissy, 1984) . Similar problems have been re-ported for other decapod species (D'Abramoet al., 1981) .

Preliminary analyses of the pigment composi-tion of marron grown under different conditionsrevealed that intensively reared animals weredeficient in carotenoids . Based on these results, afeeding trial was undertaken to correct possiblepigment deficiencies using mass-cultured microal-gae. The species chosen for this study wasDunaliella salina (Chlorophyta, Volvocales), ahalotolerant green alga produced commercially asa source of beta-carotene (Borowitzka &Borowitzka, 1988) .

Fresh concentrated and spray-dried formu-lations produced by Western BiotechnologyLimited were added to a crustacean reference diet(HFX CRD), formulated to isolate the effects ofindividual components . Juvenile marron fed puri-fied rations containing microalgal supplements(10% by weight) showed elevated levels of totalcarotenoid and beta-carotene in a 100-day trial .Dunaliella salina appears to be a particularly rich

source of carotenoids, as total carotenoid levels inalgal-fed groups exceeded those observed inpond-grown animals with access to natural feeds .An unexpected result was that the growth ofmarron was significantly stimulated in the groupreceiving fresh algal slurry. The treatment thatwas fed algal meal showed no such effect, indi-cating the presence of a heat-labile growth factorin Dunaliella salina . This component remains asyet unidentified (Sommer, 1988) .

Trout

Salmonids are known to be incapable of de novosynthesis of carotenoids and therefore requiredietary supplementation in order to ensure ade-quate pigmentation. Carotenoids also may have anumber of other nutritional and non-nutritionalbenefits (Craik, 1985 ; Torrissen, 1984) . At pre-sent, synthetic canthaxanthin and astaxanthinremain the major commercial sources of caro-tenoid, although some attempts have been madeto use other natural sources, generally of limitedsupply (Spinelli et al., 1974 ; Johnson et al., 1977) .We have demonstrated recently the effec-

tiveness of using natural astaxanthin from thegenus Haematococcus (Haematococcaceae, Chlo-rophyta) . Haematococcus pluvialis has been foundto accumulate significant amounts of carotenoidpigment in the spore phase of its life cycle(Goodwin & Jamikorn, 1954) in response tovarious environmental conditions (Droop, 1954,1955). In a 100-day feeding trial, young rainbowtrout, Oncorhynchus mykiss (Salmo gairdneri),were given pelletized diets containing intact orbroken (homogenized) spray-dried spores. Bothdiets resulted in significant deposition of caro-tenoid and astaxanthin in the trout flesh, as wellas enhanced coloration relative to a controlration. Homogenization of spores clearly in-creased the bioavailability of the algal pigments asthe diet containing broken spores was superior forall parameters measured . Similar trends werenoted in skin pigmentation . No differences ingrowth were detected .

It appears, however, that Haematococcus plu-

vialis spores do not perform as well as commer-cially available synthetic forms of astaxanthin .The algae-containing diets were compared todiets containing synthetic astaxanthin (RocheCarophyll Pink) at a similar concentration, ap-proximately 40 mg total canotenoid/kg feed . Finaltotal carotenoid and astaxanthin levels forCarophyll Pink were at least 65 % higher thanwith broken spores .

The lower efficacy of the algal carotenoids islikely a result of the presence of a large percentageof esterified astaxanthin, previously reported to beless efficient than non-esterified forms such assynthetic Carophyll Pink (Storrebakken et al.,1987). Incomplete breakage of algal spores duringhomogenization also may have decreased theincorporation of algal carotenoids .

Discussion

The results to date on the use of processedmicroalgae in aquaculture have been generally po-sitive, although there have been some obviousdifficulties with species such as trout, which nor-mally would not have a significant vegetable com-ponent in its diet. Notable successes in this areaare the application of frozen concentrates ofmicroalgae to mollusc and shellfish culture aseither primary or reserve feed sources . Variableresults for other species may be due, at least inpart, to the processing method, which determinesparticle size, cell wall integrity and nutrientstability . Culture-vessel design is also a criticalfactor when microalgae are used as a suspensionin order to avoid build-up of uneaten food .

The studies reviewed also show that aquacul-ture species usually benefit from a mixed dietrather than from algae alone, in spite of the factthat many groups (e.g . rotifers and cyprinids) areknown planktivores . In some cases (e.g . marron,grass carp and Tilapia), the addition of relativelysmall amounts of algal biomass to purified dietshas been observed to result in significant improve-ments in growth and pigmentation . Thus,microalgae have a clear role in dietary supple-ments to fulfill specific nutritional requirements .

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Pigmentation is one of the obvious applications inthe short term ; possible future developments in-clude cultivation of microalgae for long-chain po-lyunsaturated fatty acids and vitamins .

In general, mass cultured algal biomassremains a poorly studied subject and further im-provements in quality and consistency are prob-able. As yet, few algal species have been tested inprocessed form, and more attention must be paidto providing formulations for individual animalspecies . Preservation technologies such asmicroencapsulation may play a key role as theymay enhance both nutrient stability and the sus-pension properties of algae. Other important re-search areas include cryopreservation and ad-dition of antibiotics as preservation methods .

Ultimately the future use of processed, mass-cultured biomass will depend largely on the costof production . Low-cost estimates have beenobtained for conventional culture systems, but themost economical algae may come from waste-water-based facilities . Indeed, cost estimates areextremely low (Shelef et al., 1978) and feedingtrials have been promising (Shelef et al., 1980) .

ReferencesAtack, T . H . & A . J. Matty, 1978 . The evaluation of single cell

proteins in the diet of rainbow trout. II . The determinationof net protein utilization, biological values and true digesti-bility . Symp . Fin-Fish Nutr . and Feed Technol., HamburgF.R.G. 20 June 1978. E .I .F.A.C./78/Symp. E/59 FAO,Rome, FAO Access No 41435, 21 pp .

Atack, T . H ., K . Jauncey & A . J. Matty, 1979 . Utilization ofsome single cell proteins by fingerling mirror carp(Cyprinus carpio). Aquaculture 18 : 337-348 .

Becker, E. W., 1986 . Nutritional properties of microalgae :potential and constraints. In A. Richmond (ed.), CRCHandbook of Microalgal Mass Culture . CRC Press, BocaRaton, Florida : 339-419 .

Ben-Amotz, A. & H. Rosenthal, 1981 . Cryopreservation ofmarine unicellular algae and early life stages of fish for usein mariculture. In H. Rosenthal & O . H. Oren (eds),European Mariculture Soc. Special Publication No . 6 :149-162 .

Borowitzka, M. A. & L . J. Borowitzka, 1988 . Micro-algalBiotechnology. Cambridge University Press, Cambridge,477 pp .

Brown, A., 1972. Experimental techniques for preservingdiatoms used as food for larval Penaeus aztecus. Proc .Natn. Shellfisheries Ass . 62 : 21-26 .

Chanley, P . & R . F . Normandin, 1967 . Use of artificial foods

442

for larvae of the hard clam Mercenaria mercenaria (L .) .Proc. Natn. Shellfisheries Ass . 57 : 31-37 .

Choubert, G., 1979. Tentative utilization of spirulin algae asa source of carotenoid pigments for rainbow trout. Aqua-culture 18 : 135-143 .

Craik, J . C . A., 1985. Egg quality and egg pigment content insalmonid fishes . Aquaculture 47 : 61-88 .

D'Abramo, L. R., C . E . Bordner, D. E. Conklin & N . A.Baum, 1981 . Successful artificial diets for the culture ofjuvenile lobsters . Proc . World Maricult . Soc . 12 : 325,

De Pauw, N ., J. Verboven & C. Claus, 1983 . Large-scalemicroalgae production for nursery rearing of marine bi-valves . Aquaculture Engineering 2: 27-47 .

De Pauw, N ., J . Morales & G. Persoone, 1984. Mass cultureof microalgae in aquaculture systems : progress andconstraints. Proc. int . Seaweed Symp . 11 : 121-134 .

Dickson, M. W., 1987 . Pilot scale cultivation of microalgae asan ingredient for fish feeds in Zambia . Aquacult . Fish .Manag. 18 : 109-120 .

Droop, M. R., 1954. Conditions governing haemotochromeformation and loss in the alga Haematococcus pluvialis .Flowtow . Arch . Mikrobiol . 20 : 391-397 .

Droop, M. R ., 1955 . Some factors governing encystment inHaematococcus pluvialis . Arch . Mikrobiol . 21 : 267-272.

Fox, J. M., 1983 . Intensive algal culture techniques . In J . P.McVey (ed .), CRC Handbook of Mariculture: CrustaceanAquaculture . CRC Press, Boca Raton, Florida : 15-41 .

Gatesoupe, F . J . & P. Luquet, 1981 . Practical diet for massculture of the rotifer Branchionus plicatilis : application tolarval rearing of the sea bass, Dicentrarchus labrax . Aqua-culture 22 : 149-163 .

Gatesoupe, F. J . & J . Robin, 1981 . Commercial single cellproteins either as sole food source or in formulated dietsfor intensive and continuous production of rotifer(Branchionus plicatilis). Aquaculture 25 : 1-15 .

Goodwin, T. W. & M. Jamikorn, 1954 . Studies in caroteno-genesis . II . Carotenoid synthesis in the algaHaematococcus pluvialis . Biochem . J. 57 : 376-381 .

Griffith, G . W., M . A. Murphy-Kenslow & L. A. Ross, 1973 .A mass culture method for Tetraselmis sp ., a promisingfood for larval crustaceans. Proc . World Maricult . Soc . 4 :289 .

Hidu, H. & R. Ukeles, 1962. Dried unicellular algae as foodfor larvae of the hard shell clam, Mercenaria mercenaria .Proc. Natn. Shellfisheries . Ass . 53 : 85-101 .

Hirayama, K. & K. Nakamura, 1976 . Fundamental studiesin the physiology of rotifers in mass culture - V. Drychlorella powder as food for rotifers . Aquaculture 8 :301-307 .

Holliday, J . E., 1986 . International developments in oysterhatchery technology. Dept. of Agricult ., New SouthWales, Division of Fisheries Misc . Bulletin 1, ISSN0815-8819, 123 pp .

Johnson, D . A ., 1980 . Evaluation of various diets for optimalgrowth and survival of selected life stages of Artemia . InG. Persoone, P . Sorgeloos, O . Roels & E. Jaspers (eds),

The Brine Shrimp Artemia, Vol . 3 . Ecology, Culturing,Use in Aquaculture . Universa Press, Wetteren, Belgium :185-192 .

Johnson, E . A ., D. E. Conklin & M. J . Lewis, 1977 . Phaffiarhodomyza as a dietary pigment source for salmonids andcrustaceans . J . Fish . Res . Bd Can . 34 : 2417-2421 .

Kesamaru, K .& I . Miyazono, 1978a. Studies on the nutritionof Tilapia nilotica . I. The growth of T . nilotica on dietscontaining various dietary protein . Miyazaki DaigakuNogakubu Kenkyu Hokoku 25 : 341-349 (in Japanese).

Kesamaru, K . & I . Miyazono, 1978b . Studies on the nutritionof Tilapia nilotica. II. The nutritive values of diets con-taining various dietary protein. Miyazaki DaigakuNogakubu Kenkyu Hokoku 25 : 351-359 (in Japanese).

Liao I . C ., H . M. Su & J . H. Lin, 1983 . Larval foods forpenaeid prawns . In J . P. McVey (ed.), CRC Handbook ofMariculture : Crustacean Aquaculture . CRC Press, BocaRaton, Florida : 43-69 .

Lim, C., P. Suraniranat & R . Platon, 1978 . A preliminarystudy on the evaluation of casein, shrimp meal, squid mealand Spirulina as protein sources of Penaeus monodon(fabricus) postlarvae . Q . Res . Ep . - Southeast Asian Fish .Dev. Cent ., Aquacul. Dept . 2(2) : 13-18 .

Lim, C., P. Suraniranat & R . Platon, 1979 . Evaluation ofvarious protein sources for Penaeus monodon postlarvae .Kalikasan, Philipp . J. Biol. 8(1) : 29-36 .

Masson, M., 1977. Observations on the feeding of larvae ofMytilus galloprovincialis with inert foods . Mar. Biol. 40 :157-164 .

Matsuno, J ., S . Nagata, M . Iwahashi, T. Koike & M. Okada,1979. Intensification of color of fancy red carp withzeaxanthin and mixoxanthophyll, major carotenoid con-stituents of Spirulina . Bull . Jap . Soc. Sci. Fish . 45 : 627-632(in Japanese).

Matsuno, T., M. Katsuyama, M . Iwahashi, T . Koike & M .Okada, 1980 . Intensification of color of red tilapia withlutein, rhodoxanthin and Spirulina . Bull . Jap . Soc . Sci .Fish . 46 : 479-482 (in Japanese) .

Matty, A . & P . Smith, 1978. Evaluation of a yeast, bacteriumand an alga as a protein source for rainbow trout . Part I.Effect of protein level on growth, growth conversion ef-ficiency and protein conversion efficiency. Aquaculture14 : 235-246 .

Meske, C. & E . Pfeffer, 1977. Untersuchungen uber mikro-algen . Hefe oder casein als komponenten eines fischmehl-freien trockenfutters fur karpfun . Z . Tierphysiol. Tierer-nahr. Futtermittelkd. 38 : 177-185 .

Meske, C. & E. Pfeffer, 1978 . Growth experiments with carpand grass carp. Arch. Hydrobiol. 11 : 98-107.

Millamena, O. & E . J . Aujero, 1978 . Preserved algae as foodfor Penaeus monodon larvae . Q. Res. Rep. SoutheastAsian Fish. Dev. Cent. Aquacult . Dept . 2(4) : 15-16.

Mock, C. R., D . B . Revera & C . T. Fontaine, 1980. The larvalculture of Penaeus stylorostris using modifications of theGalveston Laboratory Technique . Proc . World Maricult .Soc . 11 : 102-117 .

Mohn, F. H ., 1980 . Experiences and strategies in the re-covery of biomass from mass culture of microalgae. In G.Shelef & C. J . Soeder (eds), Algae Biomass . El-sevier/North-Holland, Amsterdam : 547-572.

Mohn, F. H ., 1988. Harvesting of micro-algal biomass, InM. A. Borowitzka & L . J . Borowitzka (eds), Micro-algalBiotechnology . Cambridge University Press, Cambridge :395-414 .

Morrissy, N . A., 1984. Assessment of artificial feeds forbattery culture of a fresh water crayfish, marron (Cheraxtenuimanus) (Decapoda : Parastacidae). Dept. Fish. Wildl .West. Aust . Rept. No. 63, 43 pp .

Morse, A. N. C., C . A. Froyd & D . F . Morse, 1984 . Mole-cules from cyanobacteria and red algae that induce larvalsettlement and metamorphosis in the mollusc Haliotisrufescens. Mar . Biol . 81 : 293-298 .

Person-Le Ruyet, J ., 1975 . Techniques of mass culture of arotifer (Branchionus plicatilis Muller) and a branchiopodcrustacean (Artemia salina L .) . 10th European Symp . Mar .Biol ., Ostend, Belgium, 17-23 Sept . 3 : 331-343 .

Person-Le Ruyet, J ., 1976. Rearing of Artemia salina(Branchiopoda) larvae on inert food : Spirulina maxima(Cyanophycea) . Aquaculture 8 : 157-167 .

Reed, J . R., G. L. Samsel, R . R. Daub & G. G . Llewellyn,1974. Oxidation pond algae as a supplement for commer-cial catfish feed . Proc . Ann. Conf. Southeast Ass . GameFish Commrs, 27 : 465-470 .

Richmond, A ., 1986. CRC Handbook of Microalgal MassCulture . CRC Press, Boca Raton, Florida, 528 pp .

Sandbank, E . & B. Hepher, 1978 . The utilization of micro-algae as feed for fish. Arch. Hydrobiol. 11 : 108-120 .

Sandbank, E. & B. Hepher, 1980. Microalgae grown inwastewater as an ingredient in the diet of warmwater fish.In G. Shelef & C. J . Soeder (eds), Algae Biomass . Elsevier/North-Holland, Amsterdam: 691-706 .

Scott, A . P . & C . Middleton, 1979 . Unicellular algae as a foodfor turbot (Scophthalmus maximus L .) larvae - the impor-tance of long chain polyunsaturated fatty acids . Aquacul-ture 18 : 227-240.

Shelef, G ., G. Oron & R. Moraine, 1978 . Economic aspectsof microalgae production on sewage . Arch . Hydrobiol . 11 :281-294.

Shelef, G., Y . Azov, R. Moraine & G. Oron, 1980 . Algalbiomass as an integral part of wastewater treatment andreclamation system . In G. Shelef & C. J . Soeder (eds),Algae Biomass . Elsevier/ North-Holland Amsterdam :163-189.

Sommer, T . R., 1988 . Algal mass culture technology : applica-

443

tions for shellfish production . In L. H. Evans & D.O'Sullivan (eds), First Australian Shellfish AquacultureConference Proceedings . Curtin University Press,Australia : 226-233 .

Soong, P., 1980. Production and development of Chlorellaand Spirulina in Taiwan . In G. Shelef & C. J . Soeder (eds),Algae Biomass . Elsevier/ North-Holland, Amsterdam :97-113 .

Sorgeloos, P ., 1973. High density culturing of the brineshrimp Artemia salina L . Aquaculture 1 : 385-391 .

Sorgeloos, P ., 1974 . The influence of algal food preparationon its nutritional efficiency for Artemia salina L . larvae.Thalassia Jugoslavica 10(1/2) : 313-320 .

Spinelli, J ., L . Lehman & D . Wieg, 1974 . Composition, pro-cessing and utilization of red crab (Pleuroncoides pla-nipes). J . Fish . Res . Bd Can. 31 : 1025-1029 .

Stanley, J . G. & J . B . Jones, 1976. Feeding algae to fish.Aquaculture 7 : 219-223 .

Storrebakken, T ., P. Foss, K . Schiedt, E. Austreng, S .Liaeen-Jensen & U. Manz, 1987. Carotenoid diets insalmonids . IV. Pigmentation of Atlantic salmon withastaxanthin, astaxanthin dipalmitate and canthaxanthin .Aquaculture 65 : 279-292 .

Takano, H., 1967 . Rearing experiments of brine shrimp ondiatom diet. Bull. Tokai Reg . Fish . Res . Lab . 52 : 1-11 .

Tanaka, Y., 1978 . Comparative biochemical studies on caro-tenoids in aquatic animals . Mem. Fac . Fish ., KagoshimaUniv. 27 : 355-422 .

Tanaka, Y., H . Matsuguchi, T. Katayama, R. L ., Simpson &C. O . Chichester, 1976 . The biosynthesis of astaxanthin -XVIII. The metabolism of the carotenoids in the prawn,Penaeus japonicus Bate. Bull. Jap. Soc . Sci. Fish . 42 :197-202 .

Torrissen, O . J ., 1984 . Pigmentation of salmonids : effect ofcarotenoids in eggs and start-feeding diet on survival andgrowth rate. Aquaculture 43 : 185-193 .

Walne, P. R ., 1979 . Culture of bivalve molluscs - 50 yearsexperience at Conway. Fishing News Books Ltd .,Farnham, Surrey, England, 191 pp .

Watanabe, T . C ., C . Kitajima & S . Fujuta, 1983 . Nutritionalvalue of live organisms used in Japan for mass propagationof fish : A review. Aquaculture 34 : 115-143 .

Yannai, S ., S . Mokady, K. Sachs, B . Kantorowitz & Z. Berk,1980. Certain contaminants in algae and in animals fedalgae-containing diets, and secondary toxicity of the algae .In G. Shelef & C . J. Soeder (eds), Algae Biomass .Elsevier/North-Holland, Amsterdam: 757-766 .