Aquaculture Nutrition 2002 8; 249-256. . . . . . . . . . . . . . . . . . . . . . .

Experimental broodstock diets as partial fresh foodsubstitutes in white shrimp Litopenaeus vannamei B.

R. WOUTERSi, B. ZAMBRAN01, M. ESP IN I, J. CAL DE RON I, P. LAVENS2 & P. SORGELOOS2ICENAIM-ESPOL Foundation, Guayaqui/, Ecuador; 2Laboratory ol Aquaculture & Artemia Relerence Center. Ghent University,

Gent, Belgium

Abstract

In the first experiment, conducted in a research facility,Litopenaeus vannamei broodstock were fed either a 100%fresh food control treatment (FRE, consisting of frozensquid, oyster, musseI and enriched Artemia biomass in a2.3:1.4:1.3:1dry matter ratio) or one ofthe two treatments inwhich 50% [dry matter (DM)] of the fresh food wassubstituted with experimental artificial diets: a dry diet basedon freeze-dried Artemia biomass (ART) and a control drydiet (CON). In the second experiment, conducted in acommercial hatchery, shrimp broodstock were fed either afresh rat ion (FRE, consisting of frozen squid, polychaetesand enriched Artemia biomass in a 2.5:1.5:1DM ratio) or thesame experimental artificial diets (ART and CON) replacing50% of the DM by elimination of polychaetes and Artemiabiomass. In experiment I treatments CON and ARTproduced better results (P = 0.05) than treatment FRE interms of spawn performance and egg production per female.In experiment 2 no differences were detected among treat-ments FRE and CON whereas treatment ART performedbetter (P = 0.05) in terms of spawning, egg production perfemale and spermatophore quality. Broodstock survival andoffspring quality did not differ between treatments in eitherexperiment.

KEY WORDS: diets, maturation, nutrition, reproduction,shrimp

Rcceived 23 February 2001, accepted 8 November 2001

Correspondence: R. Wouters, LaboralOry of Aquaculture & ArtemiaReference Center, Ghent University. Rozier 44, B-9oooGent, Belgium.E-mail: r outers@inve.be

250 R.Wouters et al.

fresh-frozen Artemia biomass improved L. vannameirepro-ductive output and larval quality. Spawners that receivedArtemia biomass showed higher survival percentages andbetter ovarian maturation, spawning and repeated spawningperformance. Moreover, the spawners receiving Artemiabiomass produced better offspring in terms of egg hatch,larval survival and larval length. Artemia biomass iscollected from salt lakes, salinas, man-managed pondproductions and intensive culture systems for use in shrimpand fish hatcheries (Lavens & Sorgeloos 1996). With theincreasing threat of viral pathogens worldwide, seriouslyaffecting hatchery and grow-out production in the shrimpindustry, the need emerges for improved hygiene and strictbiosecurity (Browdy 1998). This inc1udes the use of dryfeeds that are free of pathogens. The process of making adry extruded broodstock diet - preconditioning, extrusionand drying (Harper 1988) - will indeed eliminate viabiebacteria and viruses (Chris Dinneweth, INVE TECHNOL-OGIES N.V., Baasrode, Belgium) because of the heattreatment (Chang et al. 1998)and the extraction of water.Several studies in Thailand showed that the processingtemperatures and drying used for preparation of shrimphead meal and the temperatures for pellet production aresufficient to inactivate any white spot virus or yellow headvirus that might be present (Flegel 2001). Although the useof fresh-frozen Artemia biomass has not been associated

with an increased risk of infections, hatchery managersprefer dry diets to natural ingredients. Processing thisArtemia biomass into a meal and incorporating it into anextruded broodstock diet could help hatchery managers toreduce the risk of transmitting pathogens to the shrimpbroodstock (Harrison 1990, 1997).The question remains ifthe beneficial effects of frozen Artemia biomass on shrimp.reproductive performance are maintained after these pro-cessing steps. It was as such an additional aim of this studyto verify this.

Materials and methods

Experiment 1:Research facility

Animals Wild L. vannamei were caught by artisanal fisher-men on the Ecuadorian coast between Ayangue and Olón(Guayas Province) and brought to the CENAIM researchfacilities in San Pedro. Upon arrival animals were treatedagainst filamentous bacteria, fungal and protozoan infectionswith formalin according to the method described by Simon(1982) and kept in maturation tanks. Once enough animaIswere available for the experimental work, the animals were

acc1imated to the experimental conditions for a period of2 weeks during which they were red on the differentexperimental diets described below.

Experimental conditions Unilateral eye-stalk ablation was

applied to the females by cutting and pinching, and theintact eye-stalk was marked with numbered rings to allowindividual monitoring. Each tank was stocked with 40

females and 45 males. Culture conditions, daily routineand monitoring of evaluation parameters related to brood-stock performance and offspring quality were as describedby Wouters et al. (1999). Oval-shaped (5 x 3 m; 19.6m2)black fibreglass maturation tanks were used, supplied withsand-filtered and UV-treated sea water from a reservoir

tank. Water was exchanged at a rate of 250% daily tokeep water quality optimal and similar in all tanks. Watertemperature in the maturation tanks was 29.4 :!::0.3 °C,salinity 32.7:!:: 0.8 g L-I, and pH 8.4 :!::O.I. A timer-controlled, inverted photoperiod of 14 h light:lO h darkwas adopted, with gradual transition between light anddark hours. Mated females were transferred to individual

300-L black spawning tanks, and from each spawn theeggs were hatched out in 20-L buckets. Nauplii werecollected after phototactic selection and stocked in l-L

bottles at a density of 100 L-1 and a temperature of 29°Cuntil metamorphosis to zoea 1 (ZI). The hatching percent-age was estimated by concentrating the viabIe nauplii in a10 L bucket and counting five subsamples. The percentageof egg fertilization was determined by the presence of adouble membrane and/or embryonic development. Zoea Ilength was measured with a profile projector on samples of30 zoea each. Spermatophore quality was based on spermcount and spermatophore weight (according Alfaro &Lozano 1993).

Dietary treatments During the acclimation period a feedingrate of 2.1% day-I dry matter (DM) of the total shrimpbiomass was applied. After ablation the feeding rate wasincreased to 3.15% day-I DM. One dietary treatmentconsisted of a feedingregime of frozen fresh food containingsquid, oyster, mussel and enriched Artemia biomass in a2.3:1.4:1.3:1 ratio (DM) and is denominated 'FRE'. Theenriched Artemia biomass was ongrown Artemia harvestedfrom salt evaporation ponds at San Francisco Bay (USA)and enriched with menhaden fish oil and astaxanthin

according to the standard bio-encapsulation method usedby San Francisco Bay Brand Inc (CA, USA). In twoadditional dietary treatments, 50% DM of the fresh foodwas substituted with experimental dry diets. In these latter

@2002 Blackwell Science Ltd Aquaculture Nutrition 8; 249-256

Experimental broodstock diets for shrimp Litopenaeus vannamei 251

treatments, the enriched Artemia was completely substituted,

while squid, oyster and musselwere fed in reduced quanûties.The two experimental dry diets were formulated to beisolipidic and iso-nitrogenous (Tabie I): diet CON (controldiet), and diet ART (diet containing 33% Artemia meal).

The Artemia meal was also a SFBB product provided to usby INVE Americas Inc (Salt Lake City, UT, USA). Thisproduct was freeze-dried and ground through a 500-1UIlscreen. AH the ingredients (Tabie 1) were mixed with 45%(w/w) warm water (100°C) and the resulting dough washeated and pressed through the 3-mm orifice die of a semi-

Table I Composition of the artificial broodstock diets fed toLitopenaeus vannamei(% dry matter) in experiments 1 and 2

CON ART

Experiment 1 & 2 Experiment 1 Experiment 2

IngredientsSquid meal' 35Artemia meal2 0Fish meal3 15.91Krillmeal" S

Fish hydrolisates" 5Wheat glutenS 6Soybean meal' 5Wheat meal' 4Cam starch6 14.535Fish oil' 1.16

Egg lecithin8 1Cholesterol" 0.5Vitamin mix'. 2.28Mineral mix" 2.1Atractant' 1.58inder'2 1

Etoxiquin '2 0.015

Formulated compositionMoisture 6Protein 52

Lipid 10.5

19337.98336549.5651.0610.52.282.11.510.015

28209.7933654

11.7551.0610.52.282.11.510.015

65210.5

65210.5

, Rieber & Son, Bergen, Norway.2 Inve Americas Inc.. Salt Lake City, UT. USA.

3 CIPSSA, Puerto Montt. Peru.

" Profish SA, Santiago. Chile., AJimentsa, Guayaquil, Ecuador.6 Sumesa, Guayaquil, Ecuador., Pronova 8iocare, Oslo, Norway.8 Lucas Meyer. Hamburg, Germany" Sigma, St. Louis. MO. USA,. VItamin mix (mg kg-' diet): ascorbic acid, 1000; biotin. 5; Ca

pantothenate, 500; calciferol (D3), 12.7;choline, 3500; cyanocobalamine(B12).0.3; folie acid, 15; inositol, 4000; menadione (K3).40; niacine, 750;p-amino benzoic acid. 100; pyridoxine HCI, 120; riboflavin (8,2). 200;thiamine, 120;vitamin A palmitate. 67; a-tocopherol. 400."Mineral mix (mg kg-' diet): cobalt chloride. 0.249; copper sulphate. 7.7;Fe citrate, 624; KH2PO.. 7998; KlOJo 0.747; manganese sulphate, 40;sodium phosphate, 6258; sodium selenate. 0.249. zinc sulphate. 324.12Nutri-AdInternational. Kasterlee. Belgium.

iI:)2002 Blackwell Science Ltd Aquaculture Nutrition 8; 249-256

industrial meat grinder. AH holes but one of the die wereblocked to increase pressure. The strands were dried in aventilated oven at 60°C for 2 hand kept in sealed nitrogen-ftushed plasûc bags at -20°C until use. Each treatment wasfed to a singlebroodstock tank for 70 days.

Experiment 2: Commercial facility

Anima/s Wild male L. vannameiwere caught near San Pablo(Guayas Province, Ecuador) and brought to the commercialhatchery facilities of Granjas Marinas (EI Rosario S.A) inBarandua. Wild female L. vannamei were caught in theEsmeraldas Province and transported to Barandua by truck,with animals placed in individual nets in insulated tanks withoxygenated and cooled sea water. These animals were kept inrectangular cement tanks for approximately I week beforeeyestalk-ablation and transfer to the maturation tanks.

Cultureconditions Female spawners were ablated and ringedas described in experiment I. The culture condiûons in thistest were those routinely used by Granjas Marinas: round 7-ton tanks made of fibreglass, 50 females and 50 males pertank, 300% daily water exchange with sea water of approxi-mately 29°C, two air stone diffusers per tank, naturalphotoperiod. Tank bottoms were siphoned once daily.Gravid females were sourced in the evening and transferredto individual spawning tanks. Upon spawning, eggs wereconcentrated in harvesting buckets and subsamples weretaken for egg counts and further estimation of offspringquality according to the method described in experiment I.As broodstock replacement is a continuous process incommercial hatchery applications, every newly introducedfemale was marked and the monitoring of its reproductiveperformance started after 2 weeks, over a period of 50 days.In total, 107femalesweremonitored in each treatment. Each

treatment was fed to a broodstock tank for 80 days.

Dietary treatments A feedingrate of approximately 4% day-I DM was applied in aH treatments. One dietary treatmentwas the normal feeding regime of this hatchery (FRE) andconsisted of frozen fresh squid, polychaetes from Maine,USA (G/yceradibranchiata)and enriched Artemia biomass ina 2.5:1.5:I ratio (DM).

As in experiment I, 50% DM of the fresh food wasreplaced with experimental artificial diets CON and ART.In these treatments, the polychaetes and the enriched Artemiawere substituted completely, while squid was fed in the samequantity as in the FRE treatment. Formulation and prepar-ation of the artificial diets were the same as in experiment I,

252 R.Wouters et al.

except that diet ART contained 20% DM Arlemia mealinstead of 33% (Tabie I).

Statistical analyses

Because of system limitations in the experimental set-up,each dietary treatment was tested in one tank without

replication. Individually tagged animals or spawns weretaken as treatment replicates for statistical analyses. This isthe most commonly used statistical procedure applied inshrimp reproduction trials (e.g. Browdy el al. 1989; Brayel al. 1990; Robertson el al. 1991; Menasveta el al. 1994;Xu el al. 1994;Cahu el al. 1995;Cavalliel al. 1997;Naessensel al. 1997;Wyban el al. 1997;Wouters el al. 1999).Possibleeffects caused by individual variation among experimentalanimals were reduced by randomly stocking the tanks andprevious research has demonstrated that between-tankvariability is minor (Luis Gómez, CENAIM-ESPOL Foun-dation, unpublished data). Infertile spawns were not consid-ered. When necessary, data expressed in percentage orfractions were asin" transformed to obtain normal distribu-

tions, although unadjusted means are presented. One-wayANOVA(Mead el al. 1993)was applied for statistical analysis(STATISTICA, Statsoft). An ANCOVAwas applied in experi-ment 2 for the number of eggs produced per female, withnumber of spawns as covariate. Chi-square (Mead el al.

1993) was used for evaluating the number of spawns, thenumber of females with at least one spawning event, and thenumber of females with repeat spawn performance. Distri-bution-free parameters were not analysed statistically. Toallow statistical processing of survival data, each female wasassigned a calculated percentage value, termed 'useful life-time', which corresponds to the number of days survivedrelative to the total number of days of the experiment(postablation). Reference to significant differencesare at the5% level.

Results

Female performance

The results of experiments 1 and 2 are summarized inTables 2 and 3, respectively.Usefullifetime percentages werelow in both experiments and did not differ significantlyamong treatments. Tbe daily maturation frequency wassignificantlyhigher in treatment CON than in the remainingtreatments (only evaluated in experiment I). In experiment I,the spawn frequency and the total number of spawns werehigher in the treatments that received artificial diets (CONand ART) as compared with treatment FRE. This relationwas also held true with significant differences for repeatspawn performance. Tbe number of eggs produced per

.. .. .

@ 2002 Blackwell Science Ltd Aquaculture Nutrition 8; 249-256

Table 2 Reproductive perfonnance of females, spennatophore quality and offspring quality of Ulopenaeus vannamei shrimp in experiment 1

(research facility) as a function of dietary treatment. Mean ::t:SD are presented

Dietary treatments

FRE n CON n ART n

Female performanceUsefullifetime (%) 49.0 :!: 16.6' 40 46.0 :!: 16.9' 40 42.1 :I:20.7" 40

Maturation per female per day 0.114:!:0.051' S1 0.142 :I:0.064b 57 0.121 :I:0.059' 57

Spawns per day per female' 0.021 :!:0.012 40 0.043 :I:0.023 40 0.040 :I:0.025 40

Total spawns 22 60 50

No. of females with ;?;1spawn 18' 26- 23'

No. of females with ;?;2 spawns 3- 17b 14b

Fecundity (eggs per spawn x 10') 181.6 :I:76.0' 22 213.5 :I:67.8- 60 230.8 :I:80.1- 50

Eggs per female 226.8 :!: 132.8- 40 480.5 :I: 296.7b 40 501.7 :I:449.2b 40

Spermatophore qualitySperm count (106) 17.38 :!: 12.89- 37 15.57 :!:8.84- 28 21.29 :!: 14.82- 36

5permatophore weight (g) 0.068 :I:0.022- 37 0.074 :I:0.023- 28 0.076 :I:0.026- 36

Offspring qualityEgg diameter (mm) 0.270 :!:0.003- 22 0.271 :I:0.006- 60 0.271 :I:0.005- 50

Egg fertilization (%) 51.6 :I:48.3- 22 52.6 :I:47.7- 60 69.2 :I:43.6' 50Hatch (%) 39.5 :I:29.9- 22 38.4 :I:32.6- 60 52.9 :I:29.3- 50

Deformed nauplii (%)' 3.8:1: 8.0 18 3.3:1: 5.1 54 5.1:1: 6.6 45Larval survival (%)' 56.4 :!:35.3 18 66.8 :!:28.4 54 67.1 :I:24.0 45

Zoea length (jlm) 908.6 :I:84.6" 18 901.9 :I: 54.4- 54 903.6 :I:43.9- 45

1Distribution-free data were obtained. for which no statistica Ianalysis was applied.Means with different superscripts in the same row are significantly different (P S 0.05).

Experimental broodstock diets for shrimp Litopenaeus vannamei 253

female was also significantlyhigher in treatments CON andART as compared with treatment FRE. In experiment 2, thespawn frequencywas equal in treatments FRE and ART, butlower in treatment CON, while the total number of spawnsand the number of females with repeat spawn performancewere equal among treatments FRE and CON, but higher intreatment ART. This difference was statistically significantfor the number of femaleswith two or more spawningevents.Furthermore, in experiment 2 the number of eggs producedper female in treatment ART was significantlyhigher than intreatment FRE, but not significantlydifferent from treatmentCON. Fecundity, or the number of eggs released perspawning event, was not affected by dietary treatment ineither experiment.

Spermatophore quality

In experiment 1 sperm count and spermatophore weight didnot significantly differ among treatments. In experiment 2these parameters were significantlyhigher in treatment ARTthan in the remaining treatments. Sperm counts weregenerally higher in experiment 1 than in experiment 2.

Offspring quality

Offspring quality parameters were not affected by dietarytreatment in any of the experiments. In general, the quality of

e 2002 Blackwell Science Ltd Aquaculture Nutrition 8; 249-256

the offspring produced in experiment 2 was higher than inexperiment I.

Discussion

Mortality rates were high throughout both experiments,resulting in useful lifetime percentages below 50%. It isknown that adult shrimp are very sensitive to stress (Bray &Lawrence 1992;Browdy 1992;Mosquera 1999). For exam-ple, Naessens el al. (1997) report 50% mortality of wildL. vannameiduring acclimation to culture conditions. How-ever, in the present study, stressconditions were reduced to aminimum by improving transport from the beach to thehatchery facilities (shorter transport time, cooling of thetransport tanks, placing the reproducers in small individualnets), careful handling and avoiding noise. From personalexperience it seems that high mortality rates are almostinevitabie with wild reproducers of the species L. vannamei.In agreement, high femalemortalities are reported as aresuitof tank transfers and sourcing of L. vannamei (Galgani &AQUACOP 1989;Naessens el al. 1997;Sangha el al. 1998)and other species(Menasveta el al. 1994;Cavalli el a/. 1997).The only viabie way to obtain sufficientresearch data in theseconditions was to stock and monitor a large number ofanimals in the maturation tanks.

On average, 84% of the feeding regime in commercialfacilities of the western hemisphere is based on fresh food

Table 3 Reproductive perfonnance of female, spennatophore quality and offspring quality of Lilopenaeus vannamei shrimp in experiment 2

(commercial facility) as a function of dietary treatment. Means :!::stdev are presented

Dietary treatments

FRE n CON n ART n

Female performanceUsefullifetime (%)' 40.5 :t 42.4 107 44.2 :t 43.4 107 46.7 :t 41.2 107

Spawns per day per female' 0.057 :t 0.437 107 0.040 :t 0.189 107 0.051 :t 0.227 107

Total spawns 36 39 53

No. of females with 2:1spawn 25' 25' 28'

No. of females with 2: 2 spawns 8' 7' 17b

Fecundity (Eggs per spawn x 10') 195.9 :t 89.4' 36 192.2 :t 88.3' 39 231.2 :t 109.6. 53

Eggs per female 282.1 :t 187.5' 107 293.2 :t 211.8.b 107 452.2 :t 200.4 b 107

Spermatophore qualitySperm count (106) 6.23 t 5.69' 20 7.72 t 4.16' 20 12.02 :t 6.24b 20

Spermatophore weight (g) 0.0490 t 0.148' 20 0.0461 :t 0.206' 20 0.0768 t 0.226b 20

Offspring qualityEgg fertilization (%) 75.2 t 30.6' 36 75.9 t 27.0. 39 83.2 t 24.1' 53

Hatch (0/0) 72.5 t 33.1' 36 74.7 t 27.5' 39 81.1 t 25.7' 53

Deformed nauplii (0/0)1 0.9 t 0.3 36 1.0 t 0.1 39 0.9 t 0.2 53

Larval survival (0/0) 77.1 t 20.8' 36 77.8 :t 19.4' 39 69.2 t 20.2' 53

, Distribution-free data were obtained. for which no statistical analysis was applied.Means with different superscripts in the same row are significantly different (P S 0.05).

254 R.Wouters et al.

items like squid, mussel, marine Polychaetes and others,while in Asia a total dependence on fresh food seems to hethe rule (Wouters el al. 2000). The reason for this is thathigh replacement levels of fresh food with artificial dietsreduce broodstock performance and offspring quality(Harrison 1990; Bray el al. 1990; Bray & Lawrence 1992),because artificial diets do not meet the exact nutritional

requirements of shrimp during the maturation process andbecause of the preferential ingestion of fresh food overartificial diet. The present study clearly suggests thefeasibility of substituting 50% of the fresh food withartificial broodstock diets. This fresh food substitution did

not affect the response variables negatively. On the con-trary, spawn frequency doubled in experiment I (treatmentsCON and ART) and the production of eggs per femaledoubled in experiment 2 (treatment ART). In both experi-ments, repeat spawn performance was improved in thetreatments fed the artificial diets, which means that spawnerexhaustion - that typically occurs over time in captivebroodstock animals - was overcome. Female performancewas better in treatments receivingartificial diets than in thefresh food treatment, thus supporting the quality of ourpractical artificial diet. The development of the diet used inthis study was based upon the information acquired fromliterature and analysis of existing commercial broodstockdiets (Wouters el al. 2001), and a series of trial-and-errorexperiments. The present results confirm the findings ofNascimento el al. (1991) with Lilopenaeus schmitti, thatcombining fresh food and artificial diets in a shrimpbroodstock feeding regime is a better practice than relyingon fresh food alone. Several abstracts have been publishedfrom studies that also evaluated a 50% fresh food substi-

tution with dry diets: Verstraete el al. (1995) and Coutteauel al. (1998) with L. vannamei,and Denece el al. (1999)withLilopenaeus Slyliroslris.Verstraete el al. (1995) obtained anincreased maturation frequency in tanks fed the dry diet,but a decrease in egg hatching percentage and spawningsize. At the end, the production of nauplii per femaleremained unaffected by the partial fresh food replacement.Coutteau el al. (1998) obtained an improved survival rate,but an inferior production of nauplii per female. Deneceel al. (1999) obtained similar reproductive performance andnauplii quality with dry diets (50%) or fresh food. None ofthe previous studies reported results as positive as thoseobtained in the present study.

Fresh food substitution levels above 50% have not yetproven successful. In contrast, moist artificial diets orartificial diets containing minced fresh food have been usedsuccessfullyfor total fresh food substitution by Galgani el al.

(1989)and Galgani & AQUACOP (1989) for L. slyliroslris,L. vannameiand Fenneropenaeusindicus, and by Marsdenel al. (1997) with Penaeus monodon. However, these dietshave a short shelf-life and low water stability, limitingcommercial application.

It is worth emphasizing the fact that the fresh fooditems that were substituted in the present commercialhatchery trial were precisely those that are presumedindispensable for normal maturation and reproduction, i.e.bloodworms and enriched Arlemia biomass (Browdy 1992;Kawahigashi 1992; Naessens el al. 1997). In hatcheries ofthe western hemisphere, bloodworms constitute the mostexpensive broodstock diet ingredient (Rhodes el al. 1992;Kawahigashi 1992, 1998), and their replacement withdry diet is set as a priority by various authors (Harrison1997).

In a preliminary study (Wouters 2001), it was found thatincorporating freeze-driedArlemia biomass into an artificialbroodstock diet increased diet ingestion, improved gonadmaturation in female and male L. vannamei, and increasedspawning and repeat spawning performance. This beneficialeffect of Arlemia meal was, however, more pronounced inpond reproducers than in wild reproducers. The presentstudy looks further into the potential of Arlemia meal as aningredient in dry diets for wild reproducers. In experiment I,a positive effect of Arlemia meal incIusion could not beconfirmed. On the contrary, in experiment 2 the inclusion offreeze-driedArlemia to the artificial diet had various positiveeffects: more spawns, better repeat spawn performance,higher egg production per female, higher sperm counts andan increased spermatophore weight. These responses suggestthat the beneficialeffectsof fresh-frozen Arlemia biomass, asreported in Wouters el al. (1999) for the same reproductiveparameters, are maintained after processing it into a mealand including it to an artificial diet.

The results of experiment I were sometimes different tothose obtained in experiment 2 (the effect of fresh foodsubstitution, the effect of Arlemia meal incIusion, spermcounts, offspring quality). It is impossible to pinpoint onecause for these observed differences.Seasonal-environmental

effectsand geographicaleffectsmay have contributed to thesedifferences(Hansford & Marsden 1995;Marsden el al. 1997).Different maturation facilities and environmental conditions

might also have contributed to the observed variation (Bray& Lawrence 1992).

In conclusion, this study suggests the feasibility ofsubstituting 50% of the classical fresh food regime withpractical dry artificial diets in L. vannamei broodstockfacilities. In this way, bloodworms and Arlemia biomass

~ 2002 BlackwelI Science Ltd Aquaculture Nutrition 8; 249-256

Experimental broodstock diets tor shrimp Litopenaeus vannamei 255

may be deleted from the feeding regime.The use of Artemiameal appears to further improve the performance of tbeartificial diets.

Acknowledgements

Our sincere gratitude goes to David Garriques and EloyCalderón of Granjas Marinas (El Rosario S.A) for allowingus to conduct research in their facilities and for providinginvaluable assistance and advise. This work was supportedby the VLIR-Own Initiative Program of the Flemish Inter-University Council (VL.I.R). At the time ofthis study, ByronZambrano was a student of the Universidad Técnica de

Manabi (Ecuador) and Marcos Espin was a student of theEscuela Superior Politécnica del Litoral (Ecuador).

References

Alfaro, J. & Lozano, X. (1993) Development and deterioration ofspermatophores in pond-reared Penaeus VQJlll(JRlei.J. WorldAquacul/. Soc., 24, 522-529.

Bray, W.A. & Lawrence, A.L. (1992) Reproduction of Penaeusspecies in captivity. In: Marine Shrimp Cul/ure: PrinciplesandPrac/ices (Fast. A. & Lester, LJ. cds), pp. 93-170. Elsevier.Science Publishers B.V., Amsterdam, The Netherlands.

Bray, W.A., Lawrence, A.L. & Lester, L.J. (1990) Reproduction ofeyestalk-ablated Penaeus s/ylirostris fed various levels of totaldietary lipid. J. World Aquacult. Soc., 21, 41-52.

Browdy, C.L. (1992)A reviewof the reproductive biologyof Penaeusspecies: perspectives on controlled shrimp maturation systems forhigh quality nauplii production. In: Proceedingsof the SpecialSession on Shrimp Farming, World Aquacul/ure Society, Orlando,Florida. USA (Wyban, J. ed.), pp. 22-51. World AquacultureSociety, Baton Rouge, LA, USA

Browdy, C.L. (1998) Recent developments in penaeid broodstockand seed production technologies; improving the outlook forsuperior captive stocks. Aquacul/ure, 164, 3-21.

Browdy, C.L., Hadani, A., Samocha, T.M. & Loya, Y. (1989) Anevaluation of frozen Ar/emia as a dietary supplement for tbestimulation of reproduction in penaeid shrimp. In: Aquacul/ure- ABio/echnologyin Progress(De Pauw, N., Jaspers, E., Ackefors, H.& Wilkins, N. eds), pp. 617-623. European Aquaculture Society,Bredene, Belgium.

Cahu, C.L., Cuzan, G. & Quazuguel, P. (1995) Effect of highlyunsaturated fatty acids, K-tocopherol and ascorbic acid inbroodstock diet on egg composition and development of Penaeusindicus. Comp. Biochem. Physiol., 112,417-424.

Cavalli, R.O., Scardua, M.P. & Wasielesky,W.J. (1997) Reproduc-tive performance of different sized wild and pond-reared Penaeuspaulensis females. J. World Aquacult. Soc., 28, 260-267.

Chang, P.-S., Chen, L.-J. & Wang, Y.-C. (1998) The effect ofultraviolet irradiation, heat, pH, ozone, salinity and chemicaldisinfectants on the infectivityof white spot syndrome baculovirus.Aquacul/ure, 166, 1-17.

Coutteau, P., Pinon, E. & Balcazar, Y. (1998) Effectof a commercialmaturation diet on broodstock performance of Penaeusvannameiin a commercial Hatchery (Abstract). Ist Latin American ShrimpCul/ure Congressand Exhibi/ion, Panama City, Panama.

. .. .

~ 2002 Blackwell Science Ltd Aquaculture Nu/ri/ion8; 249-256

Denece, E., Pham, D. & Coutteau, P. (1999) Reproductive responseof Penaeuss/yliros/ris to a 50% substitution of fresh food by a newshrimp maturation feed. In: Book of Abstrac/s, Aquacul/ure '99,Sydney, Aus/ralia, pp. 601. World Aquaculture Society, BatonRouge, LA, USA.

Flegel, T. (2001) Shrimp head meal- does it spread disease? AsianAquacul/ureMagazine, JulY/August, 30-31.

Galgani, M.L. & AQUACOP (Goguenheim, J., Galgani, F. &Cuzon, G.) (1989) Influence du régime alimentaire sur la repro-duction en captivité de Penaeusvannameiand Penaeuss/yliros/ris.Aquacul/ure,80, 97-109.

Galgani, M.L., Cuzon, G., Galgani, F. & Goguenheim, J. (1989)Influencedu régimealimentaire sur la reproduction en captivité dePenaeusindicus.Aquacul/ure,81, 337-350.

Hansford, S. & Marsden, G. (1995) Temporal variation in egg andlarval productivity of Penaeusmonodoneyestalk ablated spawners.J. WorldAquacul/. Soc., 26, 396-405.

Harper, J.M. (1988)Effectsof extrusion processing on nutrients. In:Nu/ri/ional Evaluationof Food Processing(Karmas, E. & Hams,R.S. eds),pp. 365-391 Van Nostrand Reinhold, New York, 786pp.

Hamson, K.E. (1990) The role of nutrition in maturation, repro-duction and embryonic development of decapod crustaceans: areview.J. Shelljish Res., 9, 1-28.

Hamson, K.E. (1997) Broodstock nutrition and maturation diets.In: Crus/acean Nu/ri/ion, Advances in World Aquacul/ure(D'Abramo, L.R., Conklin, D.E. & Akiyama, D.M. eds), vol. 6, pp.390-408.The World Aquaculture Society,Baton Rouge, LA, USA.

Kawahigashi, D.K. (1992) A survey of commercial maturationtechnology in the Western hemisphere. In: Proceedings of /heSpecial Session on Shrimp Farming, World Aquaculture Society,Orlando,Florida (Wyban, J. ed.), pp. 52-54. World AquacultureSociety, Baton Rouge, LA, USA.

Lavens,P. & Sorgeloos, P. (1996)Manual on the Productionand Useof Live Foodfor Aquaculture. FAO technical paper 361. Labora/-ory of Aquaculture & Artemia Reference Center, Ghent Univer-sity, Gent, Belgium.

Marsden, G.E., McGuren, J.J. & Hansford, S.W. (1997) A rnoistartificial diet for prawn broodstock: its effect on the variabiereproductive performance of wild caught Penaeus monodon.Aquacul/ure,149, 145-156.

Mead, R., Curnow, R.N. & Hasted, A.M. (1993)Statistical Me/hodsin Agriculture and Experimental Biology. Chapman & Hall,London, UK.

Menasveta, P., Sangpradub, S. & Piyatiratitivorakul, S. (1994)Effectsof broodstock size and source on ovarian maturation andspawning of Penaeus monodon Fabricius from the Gulf ofThailand. J. World Aquacult. Soc., 25, 41-49.

Mosquera, G. (1999) La pesqueria artesanal de reproductores decamarón: Estado actual y sus perspectivas. In: Principios YCriterios TécnicosPara EI DesarroIloSus/en/able de la Pesqueriade Reproductores de Camarón (Rosero, J.Z. & Burgos, M. eds),pp. 1-31. Informe técnico del Instituto Nacional de Pesca y elPrograma de Manejo de Recursos Costeros, Guayaquil, Ecuador.

Naessens, E., Lavens, P., Gómez, L., Browdy, C., McGovern-Hopkins, K., Spencer, A., Kawahigashi, D. & Sorgeloos, P. (1997)Maturation performance of Penaeus vannamei co-fed Ar/emiabiomass preparations. Aquacul/ure, 155, 87-101.

Nascimento,LA., Bray, WA., Leung-Trujillo,l.R. & Lawrence, A.L.(1991) Reproduction of ablated and unablated Penaeus schmilli.Captivity using diets consisting of fresh-frozen natural and driedformulated feeds. Aquaculture,99, 387-398.

Pinon, E. (2000) Producing ragworms for shrimp broodstockmaturation. GlobalAquacul/ureAdvocate, 3, 82-84.

256 R.Wouters et al.

Rhodes, R.J., McGovern-Hopkins, K. & Browdy, C.L. (1992)Preliminary financial feasibility analysis of an independentmarineshrimp hatchery located in South Carolina. S.C. Marine ResourcesDivision Technical Report no. 80, I1 pp. South Carolina Wildlifeand Marine Resources Department. Charleston, SC, USA.

Robertson, L., Bray, W. & Lawrence, A. (1991) Reproductiveresponse of Penaeus stylirostris to temperature manipulation.J. World Aquacul. Soc., 22, 109--117.

Sangha, R.S., Chavez-Sanchez, M.e., Martinez-Palacios, C.A. &Martinez-Rodriguez, I.E. (1998) Supplementing L-Ascorbic-2-Polyphosphate in Broodstock Diet of Penaeus (Litopenaeus)Vannamei at a hatchery. In: Book of Abstracts, Aquaculture '98Conferenceof the World AquacultureSociety, pp. 672,Bally's, LasVegas, Nevada, USA.

Simon, e.M. (1982) Large-scale, commercial application of penaeidshrimpmaturation technology.J. WorldMaricul.Soc.,13,301-312.

Verstraete, P., De La Mora, B. & Lavens, P. (1995)Maturation ofPenaeus vannameiby using dry pelletsas a partial substitute of thenatural diet. In: Larvt95 (Lavens, P., Jaspers, E. & Roelants, I.eds), Special Publication 24, pp. 76-78, European AquacultureSociety, Gent.

Wouters, R. (2001) Importance of broodstock nutrition in Whiteshrimp Litopenaeus vannamei.Thesis submitted in fulfillment ofthe requirements for the degree of Doctor (PhD), 195pp. Facultyof Agricultural and Applied BiologicalSciences.Ghent University,Gent.

Wouters, R., Gómez, L., Lavens, P. & Calderón, J. (1999) Feedingenriched Artemia biomass to Penaeus vannamei broodstock: ltseffect on reproductive performance and larval quality. J. ShellfishRes., 18, 651-{j56.

Wouters, R., Nieto, J. & Sorgeloos, P. (2000) Artificial diets forpenaeid shrimp. GlobalAquacultureAdvocate, 3, 61-{j2.

Wouters, R., Nieto, J. & Sorgeloos, P. (2001) Penaeid shrimpbroodstock nutrition: an updated reviewon research and develop-ment. Aquaculture,202, 1-21.

Wyban, J., Martinez, G. & Sweeney,J. (1997) Adding paprika toPenaeusvannameimaturation diet improves nauplii quality. WorldAquacult., 28, 59-{j2.

Xu, X.L., Ji, W.L., CastelI,J.D. & O'Dor, R.K. (1994) Influence ofdietary lipid sources on fecundity, egg hatchability and fatty acidcomposition of Chinese prawn (Penaeus chinensis) broodstock.Aquaculture, 119, 359--370.

..............

@ 2002 Blackwell Science Ltd Aquaculture Nutrition 8; 249-256