Presentation on theme: "Comparative Study of the Reproductive Performance of Four Strains of Artemia Eythan Morenu, Alexandra Méndez, Robert J. Mayer, and Liza V. Jiménez University."— Presentation transcript:
Comparative Study of the Reproductive Performance of Four Strains of Artemia Eythan Morenu, Alexandra Méndez, Robert J. Mayer, and Liza V. Jiménez University of Puerto Rico at Aguadilla Department of Natural Sciences March 1, 2007
This presentation evaluates important aspects of the ecological physiology of the genus Artemia in Puerto 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 of hemoglobins Heat tolerance Flexibility in diet Production of resistant stages Efficient osmoregulation
oviparous ovoviviparous Life cycle of Artemia is tightly coupled to the environment Continuous reproduction Alternation of reproductive mode There are sexual and parthenogenetic species
Artemia is a very important organism from an ecological and economic perspective: Artemia biomass is used in aquaculture (fish food) Artemia are important for the production of salt and for the survival 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?
Ventilation chamber Nylon mesh (100 m) Water level Isolation chamber Plankton isolation chambers were used to isolate reproductive couples Animals grown in mass culture until sexual maturity Introduced in isolation chamber upon reaching sexual maturity
A plankton recirculation apparatus was used in the life history experiments Control chamberExperimental chamber Pump Water intake (100 m mesh) Water intake (100 m mesh) Isolation chambers Isolation chambers Water distribution pipe Rigid plastic tubing Clear plastic partitions Spigot Heater TOP VIEW 23° C Salinity of 45
Life history experiments showed that the total number of offspring produced was higher for APAR The production of nauplii was lower than that of cysts Production of mixed broods Random alternation between reproductive modes
The lifespan of APAR individuals was higher than that of the other populations Higher reproductive potential for APAR
There was a significant time - dependent reduction in reproductive potential for all 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
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 ExperimenNeem 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. Rittschof Duke 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?