Shrimp larval quality as a function ofShrimp larval quality as a function ofbroodstockbroodstock conditioncondition

Ilie S. Racotta, Elena Palacios, and Ana María Ibarra.

Programa de Acuacultura, Centro de Investigaciones Biológicas del Noroeste, La Paz, MEXICO.

Larval qualityLarval qualityPerformance during culture Performance during culture (growth, survival, physiological (growth, survival, physiological condition) condition) Spawn quality (eggs andSpawn quality (eggs and naupliinauplii) ) and larval quality (and larval quality (zoeazoea to PL)to PL)

Higher yields and profits

A priori (predictive), or a A priori (predictive), or a posteriori criteria (final)posteriori criteria (final)

Criteria of spawn and larval Criteria of spawn and larval qualityquality

Biochemical compositionBiochemical compositionMorphological (weight, size, deformities)Morphological (weight, size, deformities)Behavioral (positive phototropism, Behavioral (positive phototropism, swimming activity) swimming activity) ProductionProduction (fecundity, fertilization, (fecundity, fertilization, hatching, larvae survival)hatching, larvae survival)Stress testsStress tests (low salinity, (low salinity, formalinformalin, low , low oxygen, high ammonia)oxygen, high ammonia)

Spawn quality: biochemical Spawn quality: biochemical composition of eggs andcomposition of eggs and naupliinauplii

LecitotrophicLecitotrophic stages: their development stages: their development depends on nutrients transferred from ovaries.depends on nutrients transferred from ovaries.Initial levels and subsequent use will determine Initial levels and subsequent use will determine hatching and survival to further stageshatching and survival to further stagesA final criterion forA final criterion for broodstockbroodstock condition condition A possible predictive criterion of larval qualityA possible predictive criterion of larval quality

Biochemical composition of eggs or larvae related to a performance characteristic.Biochemicalcomponent

Relatedperformance

Reference

Triglycerides Egg developmentrate

Wickins et al., 1995

Triglycerides,carotenoids

Spawner conditionand larval survival

Palacios et al., 1999(this presentation)

EPA and DHA Fecundity, Hatching Xu et al., 1994

Lipids andcarbohydrates

Successfuldevelopment to PL

Hernández-Herreraet al., 2001 (poster)

Carotenoids in diet Survival to zoea Wyban et al., 1997

RNA/DNA ratio Feeding condition ofpostlarvae

Moss, 1995

Spawn and larval quality: Spawn and larval quality: Production variablesProduction variables

Fecundity, fertilization and hatching rates Fecundity, fertilization and hatching rates (a result of(a result of broodstockbroodstock condition)condition)

Number ofNumber of naupliinauplii. . Larval survival throughLarval survival through zoeazoea,, mysismysis andandpostlarvalpostlarval stagesstages(a result of both larval culture and(a result of both larval culture and broodstockbroodstockcondition)condition)

Postlarvae yieldPostlarvae yield

Production variables Production variables Final criteria in studies ofFinal criteria in studies of broodstockbroodstock management management or larval culture (e.g. nutrition). or larval culture (e.g. nutrition). Could be used as a predictive criteria: e.g. survival Could be used as a predictive criteria: e.g. survival to PL based on early characteristicsto PL based on early characteristics

Although intuitive, few studies have addressed the Although intuitive, few studies have addressed the suitability of such relationsuitability of such relation

Larval quality: Stress testsLarval quality: Stress tests

Based on an abrupt transfer to adverse environmental

conditions (e.g. low salinity, low temperature,

low oxygen, high ammonia) and survival assessment:

Larvae or Postlarvae

0

1020

3040

5060

7080

90

Salinity stress test: age and conditionSurvival to low salinity depends on PL age (Charmantier et al., 1988;Aquacop, 1991; Samocha et al., 1998).

Age Salinity Survival Condition Reference

PL2 18ppt 60-90% Spawner Hernandez-Herrera, et al., 2001 (poster)

PL5 14-20 ppt 0-90%* Diet* Tackaert et al., 1989, Gallardo, 1995

PL10 0-14 ppt 18-98%* Diet* Tackaert et al., 1989; Rees et al., 1994; Wouters et al., 1997

> PL15 0 ppt 39-89% Spawner Palacios et al., 1999 (this presentation); Hernandez-Herrera,et al., 2001 (poster)

> PL15 0 ppt 0-95%* Diet* Tackaert et al., 1989; 1991; Coutteau et al., 1996

* also depends on exposure duration

Use of salinity stress testWidely used as a final criterion for Widely used as a final criterion for experimental studies (e.g. nutrition) on larval experimental studies (e.g. nutrition) on larval andand postlarvalpostlarval culture.culture.Assumed as a predictive criterion for stocking Assumed as a predictive criterion for stocking in ponds and furtherin ponds and further growoutgrowout, although this , although this has not been experimentally tested.has not been experimentally tested.In early PL stages salinity stress test could be In early PL stages salinity stress test could be used as a predictive criterion of further PL used as a predictive criterion of further PL performance performance

Influence ofInfluence of broodstockbroodstockmanagement on larval qualitymanagement on larval quality

Nutrition Nutrition Environmental conditionsEnvironmental conditionsShrimp size, age and season of the yearShrimp size, age and season of the yearOrigin of shrimp Origin of shrimp Endocrine manipulationsEndocrine manipulationsReproductive exhaustionReproductive exhaustionGenetic variabilityGenetic variability

BroodstockBroodstock endocrine endocrine manipulationsmanipulations

Eyestalk ablation (which produce a decrease in Eyestalk ablation (which produce a decrease in gonad inhibiting hormone) represents by far the gonad inhibiting hormone) represents by far the most commonly used procedure for most species. most commonly used procedure for most species. Controversies exists about the consequences on Controversies exists about the consequences on spawn and larval quality.spawn and larval quality.Some alternatives such as Some alternatives such as methylfarnoseatemethylfarnoseatesupplement in the diet, orsupplement in the diet, or serotoninserotonin injection have injection have been tested on larvae production.been tested on larvae production.Other alternatives (peptides, steroids) have been Other alternatives (peptides, steroids) have been tested only on ovary development and sperm tested only on ovary development and sperm production. production.

Eyestalk ablation and Eyestalk ablation and spawning frequencyspawning frequency

eyestalk-ablated

0 spawns12345 to 67 to 10>10

unablated

Spawn and larval qualitySpawn and larval qualityProduction: quantity

0

50

100

150

200

250

300

Number of eggs Number ofnauplii

x 1

00

0

Production: quality

0

20

40

60

80

100

Fertilization Hatching

%

Unablated

Ablated

Eggs biochemical composition

0

10

20

30

40

Acylglycerides(mg)

Carotenoids(ug)

mg

or

ug /g

ab

Survival during larviculture

0

25

50

75

100

NIV ZI ZII ZIII MI MII MIII PLI

%

Reproductive exhaustionReproductive exhaustionDecline in reproductive capacity under Decline in reproductive capacity under intensive maturation conditions. intensive maturation conditions. Occurs both in males and females as a Occurs both in males and females as a consequence either of time or consecutiveconsequence either of time or consecutiverematurationsrematurations. .

Broodstock replacement (2 to 6 months)

Time spent in maturation conditionsTime in tanks Consequence Reference

at 6-8 weeks ↓ fertilization, ↓ hatching,↓ metamorphosis to zoea

Simon, 1982

1 to 7 weeks ↓ sperm count, ↓ live sperm↑ abnormal sperm

Leung-Trujillo and Lawrence,1987

1 to 6 weeks ↓ hatching Bray et al., 1990

5 to 40 days ↓ fertilization Menasveta et al., 1993

1 to 14 weeks ↓ survival to zoea Wyban et al., 1997

18 to 96 days ↑ fecundity, ↓ fertilization↓ biochemical components

Palacios et al, 1998

15 to 75 days several traits Palacios et al, 1999

Time spent in tanks and spawn qualityTime spent in tanks and spawn quality

0

20

40

60

80

100

Fertilization Hatching

%

aab

b

15 days

45 days

75 days

0

50

100

150

200

250

300

Eggs/spawn Nauplii/spawn

x 1

00

0

bb

a

ba ab

0

5

10

15

20

25

Acyglycerides (Y1) Carotenoids (Y2)

mg/

g in

nau

plii

10

5

0

ug/g in nauplii

a

b

c

a bc

10

5ug/g in eggs

00

5

10

15

20

25

Acyglycerides (Y1) Carotenoids (Y2)

mg/

g in

egg

s

a

b b

a abb

Time spent in tanks and larval qualityTime spent in tanks and larval quality

0

20

40

60

80

100Survival to a salinity stress test

%

a

b

ab

45 days

75 days

15 days

Survival through larviculture

0

20

40

60

80

100

NIV ZI MI PLI

%

a

b

c

0

20

40

60

80

100

PL1 to PL15 (Y1) PL15 length (Y2)

% s

urvi

val

b

a a

ab b

10

5m

m

0

Consecutive spawnsSpawn order Consequence Reference

1 to 8 ↓ gonadosomatic index = fecundity and hatching

Lumare, 1979

1 to 9 ↓ hatching, = fecundity and=nauplii/spawn

Emmerson, 1980

1 to 5 = fecundity and hatching Chamberlain and Lawrence, 1981

1 to 9 = fertilization and hatching= metamorphosis to zoea

Browdy and Samocha, 1985

1 to 3 ↓ lipids in hepatopancreas Vázquez-Boucard, 1990

1 to 6 = fecundity, ↓ hatching↓ survival to zoea

Marsden et al., 1997

1 to 5 ↓ metamorphosis to zoea Wouters et al., 1999

Maturation capacity: ovary developmentMaturation capacity: ovary development

r = 0.35, p<0.01

012345678

0 5 10 15 20 25spawning order

Gon

ados

omat

ic

inde

x (%

) PVC

05

10152025303540

0 5 10 15 20 25spawning order

Mat

ure

oocy

tes

(%)

0

5

10

15

20

25

0 5 10 15 20 25spawning order

Late

Vite

lloge

nic

oocy

tes

(%)

r = 0.32, p<0.05

0

5

10

15

20

25

0 5 10 15 20 25

spawning order

Atre

sia

ocur

renc

e

Maturation capacity: ovary biochemical Maturation capacity: ovary biochemical compositioncomposition

mature

inmature

1 to 4 > 50

5

10

15

20

25

30

AC

ILG

LY

CE

RID

ES

(m

g/g

)

Maturation P < 0.05

1 to 4 > 50

10

20

30

40

50

60

TO

TA

L L

IPID

S (

mg

/g)

Maturation P < 0.05

1 to 4 > 50

20

40

60

80

100

120

TO

TA

L P

RO

TE

INS

(m

g/g)

Spawns P < 0.05Maturation P < 0.01

1 to 4 > 50

2

4

6

TO

TA

L C

AR

BO

HID

RA

TE

S

(mg/

g)

Spawn qualitySpawn quality

Fertilization rate

0

25

50

75

100

Spawning order

(%)

1st

2nd

3rd

4 to 5

7 to 12

Hatching rate

0

25

50

75

100

Spawning order

(%)

Acylglycerides in eggs

0

5

10

15

20

25

Spawning order

(mg/

g)

Acylglycerides in nauplii

0

5

10

15

20

25

Spawning order

(mg/

g)

Time in maturation tanks vs. Time in maturation tanks vs. consecutive spawnsconsecutive spawns

spawning order

0

5

10

15

20

25

30

35

401 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97

Time spent in tanks (days)

Tota

l spa

wns

/tank

1 2 3 4

5 6 7 8 +

Time spent in tanks is only partially related to consecutive spawns

Evaluation must consider separately both factors

Conclusions Conclusions Eyestalk ablation does not affect spawn and Eyestalk ablation does not affect spawn and larval quality under our conditionslarval quality under our conditionsReproductive exhaustion consist of at least Reproductive exhaustion consist of at least two factors: time spent in tanks and two factors: time spent in tanks and consecutiveconsecutive spawningsspawningsTime spent in tanks decreases spawn and Time spent in tanks decreases spawn and larval qualitylarval qualityFemale maturation capacity and spawn Female maturation capacity and spawn quality was not significantly decreased by quality was not significantly decreased by consecutive spawnsconsecutive spawns

Thank youThank you