9fcfd50d20ed062197

8/10/2019 9fcfd50d20ed062197

1/8

Panagrellus redivivusmass produced on solid media

as live food for Litopenaeus vannamei larvae

Ulfert Focken1, Christian Schlechtriem1,, Matthias von Wuthenau1, Armando Garc|a-Ortega2,

Ana Puello-Cruz2 & Klaus Becker1

1Aquaculture Systems and Animal Nutrition in the Tropics and Subtropics (480B), University of Hohenheim, Stuttgart,

Germany2CIAD (Research Centre for Food and Development), Aquaculture and Environmental Management, Mazatlan, Mexico

Correspondence: U Focken, Aquaculture Systems and Animal Nutrition in the Tropics and Subtropics (480B), University of Hohenheim

(480B), 70593 Stuttgart, Germany. E-mail: [email protected] address: Institute of Aquaculture, University of Stirling, Stirling, Scotland, UK.

Abstract

The free-living soil nematode Panagrellus redivivus is

well known to be an excellent food source for rst

feedi ng sh larvae. It represents an alternative to the

highly expensive Artemia, which is commonly used.

The lack of a proper method for mass production of

P. redivivus has prevented its wider use in commercial

hatcheries. A newcultivation method allows the pro-

duction of a sucient quantity of nematodes to deli-

ver a standardized and permanently available live

food of high quality, throughout the larval rearing

period. In two experiments ^ carried out at the Cen-tro de Investigacion en Alimentacion y Desarrollo,

Mexico ^ several feeding regimes were established to

prove the quality of the mass produced P. redivivus for

larvae of Litopenaeus vannamei, the Pacic white

shrimp. Two dierent nematode treatments were

compared with a no-feed group and a control group

that was fed withArtemia. All treatments had an ad-

ditional algal co-feed and were run in ve replicates.

Panagrellus redivivus was cultured on two dierent

media (wheat/corn our and oat our) to compare

these for their suitability as high-quality live food for

the larvae. Shrimp fed nematodes grown on wheat/

corn medium reached the postlarval stage earlier

than those from other treatments. The nematode

treatments showed promising results; however,

further research is needed on the development of im-

proved culture media or enrichment methods to

further increase the nutritional value ofP. redivivus.

Keywords: Litopenaeus vannamei, larviculture,

live food, nematodes

Introduction

The contribution of the crustacean to the world

aquaculture production values (excluding algae)

reached 22.6% in 2004. Shrimps ^ representing 83%

of crustacean production in tonnes and 85% in va-

lues ^ are the largest group of species in crustacean

farming. Most of these shrimp species derive from

the family Penaeidae. Litopenaeus vannamei contri-

butes to 47% of aquacultural shrimp production and

43% of production values (FAO 2006).

One of the major bottlenecks in aquaculture pro-

duction is the rearing of sh and crustacean larvae(Lavens & Sorgeloos 1996). This is due to the fact that

many of the species cultured depend on live

food during larval stages (Sorgeloos, Dhert & Candre-

va 2001). This live food s hould be easily available, re-

producible and economical (Watanabe & Kiron1994).

Problems occurring in supply with this live food may

prevent successful larval rearing, which limits the

whole production system (Guillaume, Kaushik, Ber-

got & Me tailler 2001).

The most frequently used live food organism is the

brine shrimp Artemiasp. This small crustacean has

the advantage that its culture can be started from

dried eggs (Sorgeloos & Persoone 1975; Liao 1992).

These dormant cysts can be stored for longer periods

in cans and, if needed, used as a convenient o-the-

shelf live food (Lavens & Sorgeloos 2000). All that is

needed for incubation is t he hydration of the cyst in

warm, aerated seawater and illumination.This is suf-

cient to start the embryonic development in the dor-

mant cysts and leads to the hatching of the nauplii

(Sorgeloos & Persoone 1975).

Aquaculture Research, 2006, 37, 1429^1436 doi: 10.1111/j.1365-2109.2006.01578.x

r 2006 The Authors

Journal Compilationr 2006 Blackwell Publishing Ltd 1429

8/10/2019 9fcfd50d20ed062197

2/8

Although Artemia is particularly convenient to use

in hatcheries (Wickins & Lee 2002), it also has some

prominent negative aspects. The most common ones

are: high costs, a highly variable hatching rate, quick

growth, the varying nutritional quality and the prop-

erty to consume algal feed and therefore to competewith the cultured species for food (Biedenbach,

Smith, Thomsen & Lawrence 1989; Lavens & Sorge-

loos 1996, 2000). The main drawback for future use

is that the cyst production in the Great Salt Lake

(Utah, USA) which is the major production site ofAr-

temia, is limited and does not satisfy the growing

world demand (Lavens & Sorgeloos 2000).

Owing to the obvious limitations ofArtemia, other

live organisms have been examined for their use in

penaeid shrimp larviculture; copepods, rotifers,

Daphnia,Moinaand nematodes have been suggested

by various authors (Wilkenfeld, Lawrence & Kuban

1984; Lavens & Sorgeloos 1996; Guillaume et al .

2001; Lee, OBryen & Marcus 2005).

Samocha and Lewinsohn (1977) reported on the

successful use of the free-living soil nematodePana-

grellusredivivus in rearingpostlarvae ofPenaeusse mi-

sculcatus and Metapenaeus stebbingi. The authors gave

nematodes in a ground mixture withSepia,Artemia,

Tubifex and Enchytraeus. Kahan, Bar-El, Brandstein,

Rigbi and Oland (1980) suggested nematodes as a po-

tential candidate for a live food organism in rearing

sh fry. Their suitable size, high nutritional values

and an easy cultivation promised nematodes to be a

valuable feed. Wilkenfeldet al. (1984) stated that thenematodes were able to substituteArtemiain penaeid

larval rearing diets. Their experiments showed the

capability ofFarfantepenaeus aztecus,Litopenaeus seti-

ferus and L. vannamei to consume and survive on

P. redivivus as the only food source from the Proto-

zoea 1 (PZ-1) stage. Experiments of Biedenbachet al.

(1989) withP. redivivusin the larval rearing ofL. van-

nameiconrmed these results.

Hitherto, nematodes are most commonly cultured

on a variety of solid and liquid media. In these pro-

duction systems, only small amounts of nematodes

could be produced.The lackof a proper mass produc-

tion technology for nematodes is the most limiting

factor to commercial application (Fisher & Fletcher

1995) and further investigation on such techniques

is recommended (Biedenbachetal . 1989).

Fisher and Fletcher (1995) produced nematodes

by the means of a biological fermenter lled with

culture medium, inoculated with Escherichia coli

and P. redivivus. Although designed for the produc-

tion of large quantities of nematodes, it seems that

this system has not yet been commercially

established.

Bedding (1981) and Bedding, Staneld and Cromp-

ton (1991) developed a solid-medium technique for

the production of entomopathogenic nematodes like

Neoplectana spp. and Heterorhabditis spp. With thenovelty of the exploitation of the third dimension,

this system enlarges the usable surface inside the

growing system by using crumbled polyether poly-

urethane sponges to create an interstitial space. This

space allowed optimal reproduction conditions and

served as a living habitat for the nematodes. It also

guaranteed sucient aeration. From the solid-med-

ium system of Bedding (1981) and Bedding et al.

(1991), Ricc i, Fi, Ragni, Schlechtriem and Focken

(2003) developed a system for the mass production

ofP. redivivus. It consisted of autoclavable plastic bags

lled with sponges soaked with medium. The bags

were inoculated with Saccharomyces cerevisiae to

guarantee a monoxenic culture. The system was

aerated and kept humid during the 11^13 days of

incubation. Several media, medium quantities and

inoculation densities have been investigated. Com-

pared withthe biological fermenter proposed by Fish-

er and Fletcher (1995), the bag system by Ricci et al.

(2003) delivers higher multiplication factors and is

less complicated to apply (Schlechtriem, Ricci, Fock-

en & Becker 2004a).

Rouse, Webster and Radwin (1992) have shown

that the nutritional character ofP. redivivus depends

on the nutritional qualities of the culture medium itis grownon.Wilkenfeld etal. (1984) used soft dough of

corn our and deionized water; Biedenbach et al.

(1989) worked with a mixture (50/50) of non-

bleached wheat our, corn meal and deionized water

to produce soft dough. Kumlu, Fletcher and Fisher

(1998) used baed 250 mL asks and a medium of

animal protein, corn oil and yeast inoculated with

E. coli. Riccietal . (2003) used an oatmeal-based med-

ium and a soluble medium made up of puried ingre-

dients, resembling the proximate composition of oat.

Additional investigations concerning the eect of an

added oil source (sh oil or sunower oil) on body

composition, average yields and multiplication fac-

tors of the nematodes were conducted by Schlech-

triem, Ricci, Focken and Becker (2004a, b). The

enrichment of culture media with further lipid

sources (capelin oil, cod liver oil and marilla oil) was

tested by Kumluetal . (1998).

There are several studies on the use of mass-pro-

ducedP. redivivus in the rearing of rst feeding sh

larvae (Santiago, Ricci & Reyes-Lampa 2004;

Nematodes as live food for shrimp larvae U Focken et al. Aquaculture Research, 2006, 37, 1429^1436

r 2006 The Authors

1430 Journal Compilationr 2006 Blackwell Publishing Ltd, Aquaculture Research, 37, 1429^1436

8/10/2019 9fcfd50d20ed062197

3/8

Schlechtriem et al. 2004a, b; Schlechtriem, Focken &

Becker 2005). The authors concluded that the bag

system is suitable for the mass production of nema-

todes as live food for rst feeding larvae of sh and

crustacean species, and Ricciet al. (2003) stated that

it should be applicable for small-scale live feed produ-cers in developing countries dueto its simple technol-

ogy. Although there are several studies of the new

mass production system and it is known thatP. redi-

vivusis a suitable food for rst feeding shrimp larvae,

no trials have been conducted to evaluate the use of

mass-produced P. redivivusin the rearing ofL. vanna-

meilarvae.

In this study, P. redivivus was mass produced

according to the method of Ricci et al. (2003) on two

types of cereal-based media that are commonly used

for the cultivation of nematodes. The suitability of

both kinds of nematodes was compared with Artemia

intheiruse as live food forrearing L. vannamei larvae.

Materials and methods

Nematode production

The nematodes were mass produced on a monoxenic

solid culture (single microorganism: Saccharomyces

cerevisiae) accordingto Ricci etal. (2003).Two dierent

culture media were used. One consisted of a mix of

wheat and corn our (50/50) (Biedenbach et al. 1989)

and the other exclusively of oatmeal (Riccietal. 2003).

The ours were mixed with a 0.8% marine salt solu-tion (Tetra Marin), and crumbled polyether polyur-

ethane sponges (75 g) were added. The mixture of

sponges and culture media was inserted into autocla-

vable bags (50 30 cm) and then autoclaved for

55 min at 121 1C. Each bag was inoculated with ap-

proximately 5.5 105 organisms ofP. redivivus. The

bags were aerated via plastic tubes; the incoming air

passed an air lter (0.2 mm) and a bottle lled with

water, resulting in a constant humidity of air. The ne-

matode culture was incubated for12 days in a climati-

callycontrolled room at an average of 22 1C.

For harvest, culture media with nematodes were

placed in a sieve clad out with a milk lter

(+200 mm, Hygia Favorit by Paul Hartmann AG,Heidenheim, Germany). This sieve was placed on a

plate half lled with water. Nematodes crawling

through the milk lter dropped into the water. This

water was ltered several times with a 112 mm plank-

ton net until most of the nematodes were removed.

The mass of nematodes was washed with distilled

water to clean them from adhering culture media or

yeast. Nematodes were harvested daily and stored

until feeding in a Petri dish in a fridge at ca.4 1C.

Feeding trials

The experimental set-up for shrimp larval rearing

was adapted from Puello-Cruz, Sangha, Jones and Le

Vay (2002). Twenty bottles with a round body and a

long neck were placed in a water bath at 28 1C in an

air-conditioned chamber at 22 1C with a 12 h dark/

light cycle. Each bottle contained 1.5 L of fresh s ea-

water at 35 1ppt. The water was aerated by the

means of plastic tubes (+0.5 cm) ending in a glass

tube, reaching down to the bottom. The current of

the air stream was regulated, so that one air bubble

per second was emitted, which guaranteed sucient

aeration and food distribution in the water column.Bottles were stocked with batches of 150 nauplii of

L. vannamei. In the rst trial, stocking was performed

using a volumetric method. Even though nauplii at

this stage still deplete internal reserves and do not

feed on algae, a mixture of 20 algalcells mL1 (70%

Chaetoceros muelleri, 30% Isochrisis galbana) was

added to guarantee feed supply once the animals

reached the protozoea stage.

Table 1 Treatments and feeds for each successive stage of larval development ofLitopenaeus vannamei

Stage Wheat/corn-nematodes Oat-nematodes Artemia Algae-only

Nauplius 5 Mixed algae: 20 cellsmL1 Mixed algae: 20 cellsmL1 Mixed algae: 20 cellsmL1 Mixed algae: 20 cellsmL1

Protozoea 1 Mixed algae: 50 cellsmL1 Mixed algae: 50 cellsmL1 Mixed algae: 50 cellsmL1 Mixed algae: 50 cellsmL1

Protozoea 2 Mixed algae: 50 cellsmL1

P. redivivus: 75mL1 (100mL1)

Mixed algae: 50 cellsmL1

P. redivivus: 75mL1 (100mL1)

Mixed algae: 50 cellsmL1 Mixed algae: 50 cellsmL1

Protozoea 3

to Mysis 3

P. redivivus: 75mL1 (150mL1) P. redivivus: 75mL1 (150mL1) Artemia: 210mL1 Mixed algae 50 cellsmL1

Number of nematodes fed in the second experiment are given in parenthesis.

P. redivivus, Panagrellus redivivus.

Aquaculture Research, 2006, 37, 1429 ^1436 Nematod es a s live fo od for s hr imp l ar vae U Focken et al.

r 2006 The Authors

Journal Compilationr 2006 Blackwell Publishing Ltd, Aquaculture Research, 37, 1429^1436 1431

8/10/2019 9fcfd50d20ed062197

4/8

Four dierent treatments with ve replicates each

were teste d (Table 1): one Artemiatreatment, two ne-

matode treatments (oat and wheat/corn) and one

treatment of algae only. In the rst stages ^ from Nau-

plii 5 to Protozoea 3 (PZ3) ^ all treatments were fed

with an algae mixture of 70% C. muelleri and 30%I. galbana. From stage PZ2 on, nematodes were given.

Owingto its size, Artemia couldonlybe fed from stage

PZ3 on. This kind of feeding had been used as Arte-

mia treatment in former experi ments in CIAD. To the

remaining ve replicates, no further food but algae

was added.

The mixture of algae was prepared from algae

(C. muelleriand I. galbana) strains regularly used in

CIAD. Algae were cultivated in aerated seawater

(35 1ppt) at a temperature of 22 1 1C.The num-

bers of cells were evaluated under the microscope,

the mixture was prepared and the appropriate

amount of algal solution (Table 1) was injected into

the bottles by means of a syringe.

Artemiacysts (Premium Brine Shrimp eggs, Prime

Artemia, Midvale, UT, USA) were incubated for 24 h at

28 1C, an average salinity of 35 ppt and constant illu-

mination.The hatched Artemia nauplii were separated

from the remaining cysts, whether unhatched or bro-

ken, and inserted into the bottles after counting.

Nematodes were constantly extracted and counted

daily. The number of nematodes per millilitre in the

resulting solution was calculated and the appropriate

amount of animals was injected into the bottles. The

numberof nematodes and Artemia andthe amount ofalgae fed were adapted towards the growing de-

mands of the growing larvae (see Table 1). In the rst

experiment, 75 nematodes mL1were given for each

developmental stage. In the second experiment,

100 nematodes mL1 were given for PZ3 and

150 nematodes mL1 for the subsequent stages. In

this experiment, the nauplii of L. vannamei were

counted individually. Apart from these changes, the

set-up of both experiments was identical. Represen-

tative samples of nematodes andArtemia were freeze

dried for later chemical analysis.

The experiments were terminated when 90% of

the shrimps in one replicate of onetreatment reached

the rst postlarval stage. The larvae and postlarvae

were counted for survival, development stages were

evaluated and the length of the animals was mea-

sured. The accumulated average dry weight of the

larvae was measured after freeze-drying.

Statistical analysis was performred with the pro-

gramme GRAPHPAD PRISM 4.03 and INSTAT 3.05. Data

were analysed using a one-way analysis of variance

(ANOVA) and the Tukeys test after testing for devia-

tions from normal distribution by the using Kolmo-

gorov^Smirnovs test. The dierences were reported

as statistically signicant whenPo0.05.

Results

In the two experiments conducted, the most striking

dierence was observed in the rates of development

and survival. In the rst experiment, all animals of

theArtemiatreatment were found in the postlarval

stage at day 11. A n average of 16% of the shrimp fed

oat-nematodes transformed into postlarval stages.

No further postlarvae were found in any other treat-

ment. (Fig.1).

In the rst experiment, the highest average survi-

val was found in the oat-nematode treatment (85.8%),followed by shrimps from algae-only treatment

(72.6%), the Artemia treatment (70.0%) and the

wheat/corn-nematode treatment (69.6%). No signi-

cant dierence in survival could be observed be-

tween the treatments from the rst trial (Table 2).

The average dry weight of the shrimps from the Arte-

mia treatment (90.9mg) was signicantlyhigher than

that of shrimps from the other treatments (Table 2).

The weight of shrimps fed oat nematodes (45.5 mg),

wheat/corn nematodes (37.9 mg) or algae-only

(30.3 mg) did not dier signicantly from each other.

Shrimps fed Artemia (5.7 mm) were signicantly

longer than the animals from other treatments.

Shrimp from the wheat/corn-nematode treatment

Artemia Oat Nem WC Nem Algae0

25

50

75

100

Mysis 3Postlarvae Mysis 2

Diet

%

Figure 1 Average number of shrimps found in the dier-

ent developmental stages in the dierent treatments from

the rst experiment (Day 11). Oat Nem, nematodes reared

on oat medium; WC Nem, nematodes reared on wheat/

corn medium.


r 2006 The Authors


8/10/2019 9fcfd50d20ed062197

5/8

(4.8 mm) were signicantly longer than shrimp algae

only (4.4 mm); shrimps fed oat nematodes (4.6 mm)

were intermediate anddid notdier from wheat/corn

nematode or algae treatment.

In the second experiment, in which the feeding

intensity for the nematode treatments had been

increased, the development in the wheat/corn nema-

tode treatment was faster. On day 9, in some repli-

cates of this treatment, all animals had reached

postlarval stage, the average was 74%, followed by

the oat-nematode treatment with 70%. Only 4% of

the shrimp from the Artemia treatment had trans-

formed to the postlarval stage at that day (Fig. 2).

Survival rates, dry weight and length at the end of

the second experiment are given in Table 3. Shrimps

fed algae-only, Artemia and wheat/corn-nematodes

had a survival rate of 90.4%,85.1% and 74.8% respec-

tively.The lowest survival rate was observed in the

oat-nematode treatment (37.1%). The survival of

shrimps fed oat-nematodes was signicantly lower

than the survival rate of shrimps fedArtemiaand al-

gae-only. The survival rate of animals fe d wheat/

corn-nematodes was not statistically dierent from

those of any other treatment. In dry weight, no sig-

nicant dierences occurred between shrimps fed

with Artemia(82.1 mg) or nematodes, whether these

were grown on oat (82.8 mg) or wheat/corn (80.2 mg)

medium.The weights of the shrimps from thesethree

treatments was signicantly higher than that of

shrimp from the algae-only treatment (26.8 mg). In

the second experiment, the average length of

shrimps fed oat nematodes or wheat/corn nematodes

was identical (5.2 mm). The dierence f rom shrimps

fed Artemia (4.8 mm) was not signicant. All three

treatments showed a s ignicant dierence in length

compared with the shrimps from the algae-only

treatment (3.7 mm).

Discussion

The experiments ended when 90% of the shrimps of

one replicate of a treatment had transformed into the

rst postlarval stage. Shrimps in the other treatments

found in larval stages ^ for example mysis ^ were

judged to show a slower development compared with

those already in the postlarval stage. During the two

experiments, it was observed that if shrimps of one

treatment performed well in terms of fastness of de-

velopment, the survival rate of the same treatment

was lowered. This may be due to the higher number

of moults that postlarvae have already performed

during their development compared with the lower

stages. Generally, the mortality in this experiment

was similar to that observed by Puello-Cruz et al.

(2002) in the same set-up (47.6^70.0%), but some-

what lower than the values observed by Wilkenfeld

et al. (1984) and Biedenbach et al. (1989), who report

survival rates between 73% and 90%.The large stan-

dard deviation indicates that survival may have also

been aected by factors not related to the feeding

Table 2 Survival rate, nal dry weight and length ofLitopenaeus vannameifrom Experiment1

Diet

Artemia Oat nematodes Wheat/corn nematodes Algae

Survival (%) 70.0 34.6 85.8 9.8 69.6 18.6 72.6 17.9

Dry weight (mg) 90.9a 15.6 45.5b 18.3 37.9b 8.2 30.3b 4.0

Length (mm) 5.7a 0.1 4.6bc 0.2 4.8b 0.2 4.4c 0.1

Mean SD, ve replicates per treatment.

Means not sharing a common superscript are statistically dierent at Po0.05.

Artemia Oat Nem WC Nem Algae0

25

50

75

100

Mysis 3

Postlarvae

Mysis 1

Mysis 2

Diet

%

Figure 2 Average number of shrimps found in the dier-

ent developmental stages in the dierent treatments from

the second experiment (Day 9). Oat Nem, Nematodes

reared on oat medium; WC Nem, Nematodes reared on

wheat/corn medium.


r 2006 The Authors


8/10/2019 9fcfd50d20ed062197

6/8

treatments, oering scope to improve survival in all

treatments. To reach postlarval stages faster means

to have shorter intermoult periods in that the animal

can replace energy losses during moults. Moulting

animals are also especially vulnerable to cannibal-

ism (Wickins & Lee 2002) and weak in the end of

moulting (Hartnoll 1982). The whole progress of

moulting and emerging from the old exosceleton is

an energy-consuming activity (Hartnoll 1982) and

all of this may weaken and stress the shrimp larvae

and could lead to a lower survival rate.

Hartnoll (1982) described the growth of crusta-

cean species as a discontinuous process with succes-

sive moults and intermoults. During the moults, the

animals shed their old integument and gain body

length and mass until the new integument has har-

dened (Wickins & Lee 2002). No major growth in

fresh weight occurs in the intermoult, which is the

time between two moults. Owing to the hard exoske-

leton, the growth is restricted and may be ignored formost purposes (Hartnoll 1982). The discontinuous

growth pattern may also explain the lack of a signi-

cant dierence in the average dry weight as observed

between shrimps from the dierent treatments of the

second trial. Shrimps fed oat-nematodes were signi-

cantly longer than shrimp from the Artemia treat-

ment and therefore a higher dry weight should be

expected. However, the growth occurring during

moulting is mainly due to the absorption of water; la-

ter, this water will be replaced gradually by proteins

(Wickins & Lee 2002). Just having passed into the

postlarval stage, this water has not been replaced by

proteins and dry weight of the freshly moulted

shrimps may be lower than that of those still in the

last larval stage.

The gradual increase in nematodes injected into

the bottles during the second experiment induced a

similar performance of larvae fed nematodes com-

pared with shrimps fed Artemia. Shrimps from both

nematode treatments outperformed those from the

algae-only treatment in all relevant criteria except

survival rate. The signicantly (Po0.05) lower survi-

val rate in the oat-nematode treatment during the

second experiment may be due to the faster develop-

ment of the shrimp larvae or to lower water quality, a

topic that is most critical during larvae culture

(Wickins & Lee 2002). In the experiment conducted

no water exchange was performed to guarantee an

undisturbed larval development. However, for feed-

ing high numbers of nematodes, a water exchange

seems crucial, due to nematodes dying and decaying

after 72 h in salt water (Biedenbachet al. 1989). The

introduction of residues of nematode culture med-

ium into the experimental system may also have a

detrimental eect on the water quality. The problem

of a lower water quality using nematodes as live feed

was described by other authors (Wilkenfeld et al.

1984; Biedenbach et al. 1989; Santiago et al. 2004).

However, washing nematodes even more thoroughly

before being fed to shrimp larvae may reduce the risk

of introducing micro-organisms or residues of cul-ture medium. A regular water exchange or adding

water during larval culture ^ as practiced in com-

mercial hatcheries ^ should further enhance water

quality. In future experiments, higher survival rates

may be accomplished if these points are taken into

consideration.

Litopenaeus vannamei has a dietary protein re-

quirement of about 20^30% (New 1980); however,

their larvae, that are more carnivorous, may have a

higher requirement (Lee, Smith & Lawrence 1984).

The body compositions of nematodes produced on

oatmeal and wheat/corn medium were described in

detail by Schlechtriemet al. (2004a) and Biedenbach

etal. (1989). Nematodesgrown on oat and wheat/corn

mediumhada crude proteincontent of 62% and 48%

in the dry matter respectively. The amino acid c om-

position of both types of nematodes was similar to

that of plankton and Artemia and can thus be consid-

ered to be appropriate to cover the essential amino

acid requirement of shrimp larvae. The lipid require-

ments of penaeid larvae are not fully understood but

Table 3 Survival rate, nal dry weight and length ofLitopenaeus vannameifrom Experiment 2

Diet

Artemia Oat nematodes Wheat/corn nematodes Algae

Survival % 85.1a 8.6 37.1b 33.8 70.8ab 30.3 90.4a 3.0

Dry weight (mg) 82.1a 8.8 82.8a 17.4 80.2a 11.9 26.8b 1.2

Length (mm) 4.8a 0.3 5.2a 0.3 5.2a 0.3 3.7b 0.2

Mean SD, ve replicates per treatment.

Means not sharing a common superscript are statistically dierent at Po0.05.


r 2006 The Authors


8/10/2019 9fcfd50d20ed062197

7/8

a crucial role of polyunsaturated fatty acids, choles-

terol and phospholipids became apparent during the

last years (Jones,Yule & Holland1997; Guillaume etal.

2001). As other animals, crustaceans are incapable of

producing linoleic acid (LIN, 18:2n6) and a-linolenic

acid (ALA, 18:3n3), but they can use these as precur-sors to synthesize the corresponding higher polyun-

saturates. However, the ability for bioconversion of

ALA and LIN to highly unsaturated fatty acids

(HUFA) as eicosapentaenoic (EPA; 20:5n3) and deco-

sahexaenoic (DHA; 20:6n3) is limited (Teshima, Ka-

nazawa & Koshio 1992) and therefore requirements

for these compounds must be satised by the diet.

Phospholipids, which play an important role in cellu-

lar membranes as well as sterols that cannot be

synthesized by crustaceans, are further essential

dietary compounds.The chemical composition of ne-

matodes can be signicantly inuenced by the com-

position of the culture medium, that is at least partly

ingested by the nematodes. The lipid class composi-

tion ofP. redivivusmass produced on dierent media

was described in detail by Schlechtriem,Tocher, Dick

and Becker (2004c). Nematodes produced on cereal-

based medium are poor in EPA and contain no DHA;

however, Schlechtriem et al. (2004b) described that

the addition of sh oil to culture media can increase

the HUFA content of the nematodes signi cantly.

The results of this study show that mass-produced

P. redivivus seems to be a potentialreplacement forAr-

temia in the larval rearing ofL. vannamei. However,

further studies are required to test whether tailoringthe body composition ofP. redivivustowards the spe-

cic need of crustacean species can further improve

the nutritional value and thus the suitability of ne-

matodes in larval rearing of shrimps.

Acknowledgment

This work was partly funded by a grant of the Eiselen

Foundation Ulm to MvW.

References

Bedding R.A. (1981) Low cost in vitro mass production of

Neoplectana and Heterorhabditis species (Nematoda) for

eld control of insect pests.Nematologica 27, 109^114.

Bedd ing R.A., Staneld M.A. & Crompton G.V. (1991)Appara-

tus and methods for rearing nematodes, fungi, tissue cultures

and the like, and for harvesting nematodes. Patent, Interna-

tional application nu mber, PCT/AU91/00136.

Biedenbach J.M., Smith L.L.,Thomsen T.K. & Lawrence A.L.

(1989) Use of the nematodePanagrellus redivivusas anAr-

temiareplacement in a larval penaeid diet. Journal of the

World Aquaculture Society 20, 61^71.

FAO (2006)FISHSTAT Plus: Universal softwarefor shery sta-

tistical timeseries.Version 2.3.2000 Fisheries Department,

Fishery Information Data and Statistic Unit Data sets

released March 2006.

Fisher C.M.L. & Fletcher D.J. (1995): Novel feeds for use in

aquaculture. Patent, International application number,

A01K67/033, A23K1/18.

Guillaume J., Kaushik S., Bergot P. & Metailler R. (2001)

Nutrition and Feeding of Fish and Crustaceans. Springer

Praxis, Chichester, Great Britain, 408pp.

Hartnoll R.G. (1982) Growth. In: The Biology of Crustacea,

Vol. 2: Embryology, Morphology, and Genetics(ed. by L.G.

Abele), pp.111^185. Academic Press, NewYork, USA.

Jones D.A.,Yule A.B. & Holland D.L. (1997) Larval nutrition.

In:Advances inWorld Aquaculture,Vol.6: Crustacean Nutri-

tion(ed. by L.R. DAbramo, D.E. Conklin & D.M. Akiyama),pp. 353^389. The World Aquaculture Society, Louisiana,

USA.

Kahan D., Bar-El T., BrandsteinY., RigbiM. & OlandB. (1980)

Free livingnematodes as a dietarysupplementin therear-

ing of sh fry and hatcheries. General Fisheries Council

for the Mediterranean.Studies and Reviews 57, 67^78.

Kumlu M., Fletcher D.J. & Fisher C.M.L. (1998) Larval pig-

mentation, survival and growth ofPenaeus indicusfed ne-

matode Panagrellus redivivus enriched with astaxanthin

and various lipids.Aquaculture Nutrition 4, 193^200.

Lavens P. & Sorgeloos P. (1996)Manual in the Production and

Use of Live Food forAquaculture.FAO, FisheriesTechnical Pa-

per (361). FAO, Rome, Italy.

Lavens P. & Sorgeloos P. (2000) The history, present status

andprospects of theavailabilityofArtemia cysts forAqua-

culture.Aquaculture 181, 397^403.

Lee C.S., OBryen P.J. & Marcus N.H., (eds) (2005) Copepods in

Aquaculture. Blackwell Publishing, Ames, IA, USA.

Lee P.G., Smith L.L. & Lawrence A.L. (1984) Digestive pro-

teases of Penaeus vannamei: relationship between enzyme

activity, size and diet.Aquaculture 42, 225^239.

Liao I-C. (1992) Penaeid larvicultu re: taiwanese method. In:

MarineShrimpCulture:Principles and Practices(ed. byA.W.

Fast & L.J. Lester),pp.193^215. Elsevier SciencePublishers

B.V., Am sterdam, the Netherlands.

New M.B. (1980) Bibliography of shrimp and prawn nutri-

tion.Aquaculture 21,101^128.Puello-Cru z A.C., Sangha R.S., Jones D.A. & Le Vay L. (2002)

Trypsin enzym activity during larval development ofLito-

penaeus vannamei (Boone) fed on live feeds. Aquaculture

Research 33, 333^338.

Ricci M., Fi A.P., Ragni A., Schlechtriem C. & Focken U.

(2003) Development of a low-cost technology for mass

production of the free-living nematodePanagrellus redivi-

vus as an alternative live food for rst feeding sh larvae.

Applied Microbiologyand Biotechnology 60, 556^559.


r 2006 The Authors


8/10/2019 9fcfd50d20ed062197

8/8

Rouse D.B.,Webster C.D. & Radwin I.A. (1992) Enhancement

of the fattyacid composition of the nematodes Panagrellus

redivivususing three dierent media. Journal of theWorld

Aquaculture Society 23, 89^95.

Santiago C.B., Ricci M. & Reyes-Lampa A. (2004) Eect of

nematodePanagrellus redivivusdensity on growth, survi-

val, feed consumption and carcass composition of big-

head carp Aristichtys nobilis (Richardson) larvae.Journal

of Applied Ichthyology 20, 22^27.

Samocha T. & Lewinsohn C. (1977) A preliminary report on

rearing penaeid shrimps in Israel. Aquaculture10, 291^292.

Schlechtriem C., Ricci M., FockenU. & Becker K.(2004a) The

suitability of the free living nematode Panagrellus redivi-

vus as live food for rst-feeding sh larvae. Journal of

Applied Ichthyology 20,161^168.

Schlechtriem C., Ricci M., Focken U. & Becker K. (2004b)

Mass produced nematodes Panagrellus redivivus as live

foodfor rearingcarp larvae. Preliminary results. Aquacul-

ture Research 35, 547^551.

Schlechtriem C., Tocher D.R., D ick J.R. & Becker K. (2004c)Incorporation and metabolism of fatty acids by desatura-

tion andelongationin the nematode Panagrellus redivivus.

Nematology 6,783^795.

Schlechtriem C., Focken U. & Becker K. (2005) Digestion and

assimilation of the free-living nematode Panagrellus redi-

vivus fed to rst feeding coregonid larvae: evidence from

histologicaland isotopic studies.Journal of theWorld Aqua-

culture Society 36, 24^31.

Sorgeloos P. & Persoone G. (1975) Technological improve-

ments for thecultivationof invertebrates as foodfor shes

and crustaceans. II. Hatching and culturing of the brine

shrimp,Artemia salinaL.Aquaculture 6, 303^317.

Sorgeloos P., Dhert P. & Candreva P. (2001) Use of the brine

shrimp, Artemia spp., in marine sh larviculture. Aqua-

culture 200, 147^149.

Teshima S., Kanazawa A. & Koshio S. (1992) Ability for

bioconversion of n-3 fatty acids in sh and crustaceans.

Oceanis 18, 67^75.

Watanabe T. & Kiron V. (1994) Review ^ prospects in larval

nutrition.Aquaculture 124, 223^251.

Wickins J.F. & Lee D.OC. (2002) Crustacean Farming Ranching

and Culture, 2nd edn. Blackwell Science, Oxford,446pp.

Wilkenf eld J.S., Lawrence A.L. & Kuban F.D. (1984) Survival,metamorphosis and growth of penaeid shrimp larvae

reared on a variety of algal and animal foods. Journal of

theWorld Maricultural Society 15, 31^49.


r 2006 The Authors


9fcfd50d20ed062197

Documents