John Jaime Perez's Presentation

1. DIATOMS AS FEED FOR AQUACULTURE
By John J. Perez C.

2. Centric diatom Pseudo-nitzschia
Thalassiosira
Pennate diatom
siliceous hoops (girdle bands)
Pores are species specific
Greek diatomos, ‘cut
in half ’
chlorophyll a, fluorescing red when
illuminated with blue Light

3. Diatoms support the most
productive fisheries

4. Crucial role of diatoms in the global carbon cycle

5. Thalassiosira pseudonana (34Mb)

6. Phaeodactylum tricornutum
(27 Mb)

7. Fragilariopsis cylindrus
(80 Mb)
Fragilariopsis cylindrus (Grunow in Cleve &
Möller) W. Krieger in Helmcke & Krieger 1954

8. Pseudo-nitzschia multiseries
(300 Mb)

9. Unique combination of genes and metabolic pathways
distinguish diatoms
Thalassiosira Two of the novel type of spores
of Chaetoceros furcillatus
nordenskioeldii
Enormous amounts of Thalassiosira taelata
Young auxospore of Pseudo-
nitzschia multiseries diversity encapsulated
within diatoms
http://www.aquatic.uoguelph.ca/Human/Research/ijkl/kaczmarskai.htm

10. Life in the ocean waves
Eukaryotic
phytoplankton Cyanobacteria
Heterotrophic
Archaea bacteria
viruses
Protists

11. Benthic diatoms are the main food
source for abalone post-larvae

12. monospecific cultures of benthic diatoms have successfully been
employed as feed for the culture of abalone post-larvae

13. in Taiwan, abalone post-larvae grown in hatcheries are usually fed with natural
populations of benthic diatoms, following the traditional method of using biofilms of
mixed benthic diatoms as the settlement substrata for abalone post-larvae in
hatcheries
a photosynthetically active biofilm of diatoms, e.g. Gyrosigma spp
Biofilm of mixed centric diatoms

14. postlarvae of various abalone species have a better growth
rate when fed with cultured diatoms than those fed with
natural unknown species of diatoms
Post Larval 'spat': After 2-3 weeks
swimming around in the water column, the pelagic
veliger larva loses its velium and metamorphoses into
the post-larval stage (spat). It loses its positive
phototaxis (movement towards the sunlight), moves
down from the water surface, and settles on hard
surfaces in intertidal and subtidal areas. Settlement is
triggered by a chemical that is produced by Coralline
algae and adult abalone. Abalone feed on Coralline
algae and the presence of adults indicates a good
habitat to live! The post-larva sheds its swimming
hairs (cilia) and begins to develop the adult shell form.
This is the first feeding stage where they start to feed
on diatoms.

15. Carbajal-Miranda
et al. (2005)
Navicula
incerta
Amphiprora
paludosa
Haliotis
rufescens

16. Daume et al. (2000)
Cylindrotheca
closterium
Haliotis rubra Amphora sp.
Navicula sp., N. jeffr Cocconeis sp

17. Gordon et al. (2006)
Haliotis discus
Amphora luciae
Navicula cf. lenzii

18. Haliotis iris
Achnanthes longipes
Kawamura et al. (1998)
Nitzschia ovalis
Nitzschia sp
Cocconeis p. Navicula britannica

19. Gallardo and
Buen (2003)
Mixed diatoms vs.
monospecific cultures of
Navicula
Haliotis asinina

20. little information
concerning
diatoms as feed
for Haliotis
diversicolor

21. Kawamura et al., 1998
Poor and unpredictable performance
of abalone postlarvae
differences in lipid,
the species of protein and
diatoms they extracellular
have been fed polymeric
substances
(EPSs)

22. Hypothetical cellular pathways and processes in iron-limited pennate diatom cells. All roman green or red type depicts
gene transcripts found to be up- or down-regulated, respectively. Italicized and underlined green type indicates
metabolites found to be enriched relative to total protein in iron-limited cells. DF, diffusion factor; EPS, extracellular
polymeric substances; FR, ferric reductase; HMA, heavy metal-associated; PCD, programmed cell death; ROS, reactive
oxygen species.

23. AIMS
• to improve the growth and the survival of
abalone post-larval stages in a specific growth
system using specific diatoms species
• a better understanding of their basic dietary
requirements
farmers attempting to produce mollusks and
crustaceans from the larval stage
• high cost of producing live food (microalgae)
• up to 30% of the total cost of production
(Valenzuela-Espinoza et al., 1999).

24. Alternative
• use immobilized
microalgae
• can be cheaper than
algae produced by
traditional methods
• ready for use (Chen,
2003).

25. Specific aims
• Survey the diversity of diatoms species found
in H. diversicolor hatcheries.
• Isolate and develop a monoculture that could
be immobilized and encapsulated in alginate
beads for long-term storage as algal stock.

26. monospecific algal stocks used as feed for
cultivating the post-larvae of H. diversicolor
• Lipids
• Proteins
• EPS
– soluble EPS
– bound EPS
– internal carbohydrate
– residual carbohydrate

27. Collection and preparatory cultures of benthic diatoms
Diatoms from small abalone
hatchery ponds
scraped from abalone post-larvae
settlement substrates (plastic plates)
collected in l L collection bottles
Yean-Chang Chen, Ph.D.
Associate Professor,
placed in a cool icebox Department of
Aquaculture,
National Taiwan Ocean
University,
transported to the Algal Laboratory Keelung, Taiwan
Email: ycchen@mail.ntou.edu.
of the National Taiwan Ocean tw
b0232@ind.ntou.edu.tw
University, Keelung, Taiwan Tel: 886 2 24622192 ext. 5221

28. Martek 120-liter Deep aerated tank used for the
culture of Nannochloropsis for
photobioreactor aquaculture

29. Eicosapentaenoic acid 20:5(n-3)
(EPA, 5,8,11,14,17-cis-eicosapentaenoic acid)
EPA is an omega-3 fatty acid
• an n-3 C20-polyunsaturated fatty acid that is
metabolically active. with a doublefrom the endstartingcarbonthe third
carbon atom
bond (C=C)
of the
after
chain.
a carboxylic acid with a 20-carbon chain and five cis double bonds
the first double bond is located at the third carbon from the omega end.

30. EPA and its derivatives have proved beneficial in prevention
and treatment of certain medical conditions
• coronary heart
disease
• blood platelet EPA is effective
aggregation also in arresting
and minimizing
• abnormal cholesterol tumor growth
levels
• several carcinomas

31. EPA is currently sourced from fish oil
• No other sources are
commercially available.
– fluctuates in price and quality.
– contamination of fish oil with
pesticides and heavy metals.
– an alternative economic and
consistent source of EPA is
needed.
– Microalgae are one
potential source.

32. Annual EPA demand
demand is expected to increase dwindling
supplies of
fish oil
125
tones in
Japan
Current market price of EPA ethyl
ester (95% pure) about $650/kg