comparative study of the reproductive performance of four strains of artemia

Comparative Study of the ReproductivePerformance of Four Strains of Artemia

Eythan Morenu, Alexandra Méndez, Robert J. Mayer, and Liza V. Jiménez

University of Puerto Rico at AguadillaDepartment of Natural Sciences

March 1, 2007

This presentation evaluates important aspects of the ecological physiology of the genus Artemia inPuerto Rico

Discussion of research data and conclusions

Background on the genus Artemia

Preliminary work – Effects of Neem on Artemia

Artemia are Anostracan Branchiopods that are well adapted to the extreme conditions of hypersaline environments

Synthesis ofhemoglobins

Heat tolerance

Flexibility in diet

Production of resistant stages

Efficient osmoregulation

oviparous

ovoviviparous

Life cycle of Artemia is tightly coupled tothe environment

Continuous reproduction

Alternation of reproductive mode

There are sexual and parthenogeneticspecies

Artemia is a very important organism from an ecological and economic perspective:

Artemia biomass is used inaquaculture (fish food)

Artemia are important for the production of salt and for thesurvival of many species of birds in salt flat systems

What is the importance of locating and characterizing populations of Artemia?

Main question

• Are there significant differences in the reproductive performance of various populations of Artemia when reared under constant conditions?

Ventilationchamber

Nylon mesh (100 m)

Water level

Isolation chamber

Plankton isolation chambers were used toisolate reproductive couples

Animals grown in mass culture until sexual maturity

Introduced in isolation chamberupon reaching sexual maturity

A plankton recirculation apparatus was used in the life history experiments

Control chamberExperimental chamber

Pump Pump

Water intake(100 m mesh)

Water intake(100 m mesh)

Isolation chambers

Isolation chambers

Water distribution pipe Water distribution pipe

Rigid plastic tubing Rigid plastic tubingClear plastic partitions

Spigot Spigot

Heater Heater

TOP VIEW

23° C

Salinity of 45

Populations

APAR LPPR CRPR GSL

Nu

mb

er o

f o

ffsp

rin

g p

rod

uce

d p

er c

oh

ort

0

400

800

1200

1600

2000

Number of nauplii

Number of cysts

Life history experiments showed that the totalnumber of offspring produced was higherfor APAR

The production of nauplii was lower than that of cysts

Production of mixed broods

Random alternationbetween reproductivemodes

Populations

APAR LPPR CRPR GSL

Lif

esp

an

(d

ays

)

0

40

80

120

160

Max = 106

Min = 72

Max = 120

Min = 72

Max = 79

Min = 36

Max = 219

Min = 75

The lifespan of APAR individuals was higherthan that of the other populations

Higher reproductivepotential for APAR

Time Units (10 days)

1 2 3 4 5 6 7 8

0

200

400

600

800

1000

GSL

Time units (10 days)

0 1 2 3 4 5 6 7 8

Nu

mb

er o

f o

ffsp

rin

g p

rod

uce

d p

er c

oh

ort

0

200

400

600

800

1000

nauplii cysts

APAR

There was a significant time - dependent reduction in reproductive potential forall populations

Conclusions

The reproductive performance of Artemia

varies between strains and is affected by

environmental conditions

A. parthenogenetica had the highest

reproductive performance of all the

population tested

This tree is originally from India.

Its many properties can be used to cure many diseases and in the creation of insecticides.

Preliminary work with neem seed extracts and Artemia suggests that this extract could increase the growth rate of these animals.

Quick facts about Neem (Azaridachta indica)

We want to know if neem seed extracts have a significant effect on the survival, growth and development of Artemia.

This research can have important aquacultural applications.

Results can shed light on the culture of other

economically important crustaceans

Future direction of the research – Neem

Neem Experiment -

Research question:How will a series of concentrations of neem seed extract affect the survival of Artemia larvae?

After 24 hours of the experimental test tubes were observed and the live and/or dead Artemia nauplii were counted.

An acute toxicity assay was performed

Concentration (g/l)

0 10 20 30 40 50

Per

cent

of L

ive

Ani

mal

s

65

70

75

80

85

90

95

100

Significant mortality at concentrations above 25 g/l

• If neem seed extract would promote a faster growth rate it could be used to accelerate development of Artemia satisfying the growing demand of Artemia in the aquaculture industry.

Future direction of the research – Neem

The reproductive performance of Artemia

varies between strains and is affected by

environmental conditions

A. parthenogenetica had the highest

reproductive performance of all the

populations tested

Reproductive Performance Experimen Neem Experiment

At concentrations of 1g/l – 25g/l Artemia nauplii had high survival

We will continue experiments to determine the effects of Neem on

development and growth of Artemia.

Acknowledgements

R. B. Forward and D. RittschofDuke University Marine Laboratory

UPR Sea Grant College Program Award Number NA16RG2278

University of Puerto Rico at Aguadilla

US Fish and Wildlife Service – Caribbean Islands NWR

Artemia Reference Center – Gent, Belgium

PR-LSAMP

The reproductive performance of Artemia

varies between strains and is affected by

environmental conditions

A. parthenogenetica had the highest

reproductive performance of all the

population tested

Reproductive Performance Experiment - Results

Neem Experiment - Importance

At concentrations of 1g/l – 25g/l Artemia organisms survived.

We will continue experiments to determine the effects of Neem on Artemia at these concentrations.

Questions?