2. BACKGROUND •Flathead grey mullet is
important aquaculture
species. Since the early
1900s, has been cultured in
semi-intensive ponds with
tilapia milk fish and carps in
Egypt, USA, Korea, Russian
and Philippines
•1990s experimental culture in
Tanzania
3. Habitat and
biology • mullet is catadromous, found
in estuaries and freshwater
areas. Adult survive btn 0‰
to 75‰, juvenile tolerate after
they reach lengths of 4–7 cm.
• mullet is a diurnal feeder,
consuming zooplankton, dead
plant matter, and detritus.
Have gizzard-like segments in
their stomach and a long GIT
that enables them to feed on
detritus..
4. GLOBAL PRODUCTION TREND OF MULLET FISH
• production of mullet
increased from 25.6 in
1997 to 147 in 2003 and
291.2 thousand tones in
2020. Egypt, being
largest producer.
• However dependence on
wild fry limit expansion
of industry.
5. TREND OF MULLET FISH PRODUCTION IN
TANZANIA
• In 1990s WIOMSA funded a project for EIM of finfish,
shellfish and seaweeds including milkfish, rabbit fish, mullet
and Zanzibar tilapia
• After the workshop, pond finfish culture spread to Tanzania
coastal. In 2006, farm at Bagamoyo produced 1 MT/ha/yr,
earning 2000 USD and the highest production of 7.5
MT/ha/yr at Ndumbwe Mtwara in 2011.
• However, mullet farming has not taken off on a commercial
scale by private operators.
8. SOURCE OF SEEDS FOR MULLET FISH
wild source
• During the autumn and winter adults migrate to the sea to
spawn. Fecundity is 0.5–2.0 million/female
• Hatching take 48 hours after fertilization, releasing larvae
approximately 2.4 mm long.
• When the larvae are 16–20 mm, they migrate to inshore
waters and estuaries, where they can be collected for
aquacultural purposes during late August to early
December.
9. CONT.…
• fry are collected by fine seine nets,
transported in seawater to hapas or
shore tanks for a few hours. then
transported to nursery facilities.
• On arrival, they are acclimatized, in
terms of salinity; it takes several
hours, and water from the nursery
pond is gradually added and mixed
with the transport water.
• 100% Mortality rates can occur few
weeks if this process is skipped
before stocking fry into the nursery.
11. HATCHERY PRODUCTION
• mature individuals (over two years, 32–50 cm long and 1.0–2.1 kg) are kept
at 32–35‰ and 12–15 °C in 2–3:1 male: female ratio.
• Females are injected with pituitary gonadotropin 2-3 injections. Females
spawn 12 hours after the last injection.
• Eggs are transferred to incubation jars and incubated at a temperature of
22–24 °C in seawater (30–32‰) saturated with oxygen. Hatching takes
place after 50–64 hours.
• After hatching, the larvae are transferred to indoor tanks and fed with live
food (rotifers, and later with Artemia nauplii) for 14 days, and then
transferred to larger tanks until they reach 10–20 mm before transport to
outdoor nursery ponds.
12. FEED SOURCE
mullet feeds on
natural food and rice
bran, extruded pellets.
Feed is formulated
according to the
dietary requirements
of the major cultured
species (i.e. tilapia and
common carp).
14. HARVESTING
TECHNIQUES •In culture system growing
season is normally about
7–8 months. mullet
reaches 0.75–1 kg
•Harvesting can be partial
or complete in ponds or
net enclosures depending
on the market
16. CONCLUSION
For future expansion of flathead grey mullet
farming in Tanzania education and training
campaign is required to raise awareness among
people living in costal areas.
~ thank you ~