Aquaculture, breeding technique, artificial manipulation

1. Environments Manipulation
on Spawning Process
Sapto Andriyono
Departemen Kelautan, FPK
Universitas Airlangga
2013

2. Out Line
• Suhu (Thermal)
• Stimulasi Cahaya (Light Stimulation)
• Bahan Kimia (Chemical)

3. Spawning?
• Spawning refers to the release of unfertilized
planktonic eggs by female fish, which is the
reproductive pattern for most marine fishes.
• The eggs are fertilized shortly after release by
males. Some fishes also deposit unfertilized
eggs in nests where they are fertilized and
develop.

4. There are three primary factors that influence
the events leading up to spawning:
• nutritional state of the female,
• physiological factors (hormones), and
• ecological factors.

5. important to spawning are:
• temperature,
• photoperiod,
• tides,
• latitude,
• water depth,
• substrate type,
• salinity, and
• exposure.

7. Findings of several studies have demonstrated that
• variety of environmental factors such as
photoperiod, temperature, rainfall, salinity;
• Biological parameters such as nutritional status
and size of fish species; and
• Farm management techniques such as feeding
rate and stocking density are significant in the
timing of reproductive activities of some seasonal
fish

8. Thermal
• Mempengaruhi faktor lingkungan lainnya
• Metabolisme tubuh
• Pada suhu 24oC - 6 kali lebih tinggi
dibanding 5oC
• Pada suhu optimum: pengambilan makanan,
laju pertumbuhan, dan laju metabolisme

9. Thermal  Reproduksi
• Perkembangan gonad  suhu, makanan,
cahaya dan musim
• Kematangan gonad  suhu, makanan,
hormonal

10. Peran suhu
• Laju pengeluaran GtH
• Respon pituitari pada GnRH
• Gonad Binding GtH
• Sintesis dan katabolisme steroid
• Merangsang GtH dalam proses pemecahan
folikel

11. • Goldfish pada suhu 20oC - GtH meningkat
dalam darah
• Pada suhu <20oC ovari berkembang tetapi
tdk ovulasi
• Pada suhu >20oC  merangsang ovulasi

12. Tipe ikan melahirkan
• Waktu melahirkan semakin singkat
• Pada suhu 18oC  18-22 hari
• Suhu 20oC 4-12 hari
• Hal ini dikarenakan memacu kerja enzime
chorionase  melunakkan

13. photoperiod and periodicity
• The daylength (photoperiod), in some cases at
least, is thought to influence the thyroid gland
and through this the fishes’ migratory activity,
which is related to gondal development
(maturation).

14. • In high latitudes, spawning is usually associated
with a definite photoperiod (and temperature),
which dictates seasonal pulses of primary
production in temperate regions to assure
survival of larvae.
• In low latitudes, where there is little variation in
daylength, temperature, and food production,
other factors may be important such as timing
with the monsoons, competition for spawning
sites, living space, or food selection.

15. • Reproductive periodicity among fishes varies
from having a short annual reproductive
period to being almost continuous.
• Thus tropical fishes spawn nearly
continuously, whereas subarctic fishes spawn
predictably during the same few weeks each
year.

16. • Generally, in species that spawn as daylength
increases, spawning occurs earlier in the year
in lower latitudes than at higher latitudes.
• In species that spawn as daylength decreases,
spawning takes place earlier in the year at
higher latitudes than at lower latitudes.

17. Photo (Cahaya)
• In the tilapia species, Ridha et al. (1998) found
a positive effect of photoperiod manipulation
on seed production in Oreochromis spilurus.
• Results of Biswas et al. (2005) suggested that
photoperiod manipulation can be used to
arrest the spawning problems in Nile tilapia
(Oreochromis niloticus).

18. • Puckhaber (1992) worked on the Lake Manzala
population and applied a 6L:18D photoperiod
manipulation for 28 days.
• the present study demonstrated that the timing
of spawning activity in Nile tilapia can be
modified by a combination of stocking density
and photoperiod manipulation.
• Tropical tilapia are territorial species, exhibit a
strong social hierarchy and need daily light cycle
and space for their reproductive activities.

19. • Transferring the fish into the single
compartments with enough holding space and
ambient photoperiod might have broken up
the social hierarchies to induce the large
number of spawns in the experimental group.
• Stocking density and photoperiod technique
as an effective tool in controlling spawning of
farmed stocks of Nile tilapia

20. • Ridha and Cruz (2000) reported poorer quality
of eggs (yolk sac and swim-up fry) from groups
treated with combination of light intensity and
photoperiod of 500 lux/18 h, 500 lux/15 h and
500 lux/12 h.
• A reduced seed kg/female/day was observed
by Ridha et al. (1998) in the 29°C/13 h
temperature / light duration treatment
compared to the ambient condition.

21. • Biswas et al. (2005) obtained poorer egg
quality and low fecundity in fish exposed to
the 6L:6D photoperiod manipulation.
• However, no loss in egg quality such as
survival of eggs and fry was experienced with
the stocking density and photoperiod
manipulation in the present work.

22. • Further investigation in this study
demonstrated that plasma estradiol-17β (E2)
concentration may have played an important
role in relation to the effect of stocking
density and photoperiod treatments on the
spawning activity of female Nile tilapia.
• Consistent with Biswas (2005), this present
study found that plasma estradiol-17β levels in
the experimental group were low immediately
after the first spawning.
• The low levels in turn may have retarded the
ovarian growth due to reduced vitellogenesis
(Foo and Lam, 1993).

23. Pheromones
• Bombykol, a fatty acid derivative that is the
sex pheromone of the silkworm
• Bombykol, a 16 carbon alkohol with two sites
of unsaturation, possesses a highly distinctive
structure which should contribute
considerably to the specificity of the signal

24. • Vertebrates secrete sex pheromones from glads
distributed throughout the body, the location of
which appear to be somethimes correlated with
the mating behaviours of the pheromone
producers.
• Male sea lampreys (Petromyzon marinus)
discharge sex pheromones as urinary products
that elicit a strong response in spawning-run
females
• Female goldfish secrete steroidal sex hormones
of presumed ovarian origin

25. • Many fish species spawn during the rainy
season in nature. By simulating the rainy
season in aquaria, difficult-to-spawn species
can be induced to spawn. Rains affect the
water chemistry, the water height, and the
water temperature.

26. • In order to simulate rainy conditions, the tank
level should be reduced to half its normal height.
Each day add 5% of the tank volume. The water
added should be very soft and slightly cooler than
the tank temperature.
• To simulate the rain, use a drip system or spray
bar for several hours a day and simulate storms
by flashing light in a dark room. Thunder can be
created by playing a recording of a storm, a
recording of music with bass.

27. • This process will stimulate some hard-to-
spawn species, but not all.
• Many species will respond to just one altered
water condition, such as a series of water
changes with soft water replacement, or a
decrease in the water temperature.

28. Vocabulary
Mating Gestation
Spawning Hatching
Fertilization Breed
Incubation time Brood

29. Review
Source
• http://repository.seafdec.org.ph/bitstream/ha
ndle/10862/564/bspcfp_p001-053.pdf
• Hand writing.
• submit on 16 March 2015
• Explained the Fig 1, Fig 2, Fig 3, Fig 4
• One person only explaining one Figure

30. TERIMA KASIH