The
fishery unit is sub –divided into two
sections namely
a. Nursery section
b. Grow out sections
Nursery section: Is the section where hypophysation (hatchery operation ) and breeding of fishes to a
transferable sizes (fingerlings)
Grow out section: It is the section where the fingerlins
that are transferred from the
nursery section are kept unit they obtain a table size before they can be transferred to the earth pond
The
major activities carried out in the
fishery unit are as follows
1.
Water treatment
2.
Washing of tank
3.
Hatchery
operation
4.
Siphoning
5.
Tank scrubbing
6.
Removal of shoot
outs and mortality
7.
Feeding
Water treatment: This
experiment was perfectly performed by automatic application of hydrated
lime in the water at the water treatment room or chamber in order to dissolve the iron molecules present in the water.
After that, the water was filtered , ozonized back washed, and treated using
filtration cylinder and ozonizer
before distribution of water to
different tanks with the aid
of hoses and taps
Washing of tanks: These are normally done manually by the aid of a brush, foam,
salt and water to wash
and rise properly.
Hatchery operation (hypophysation): The following steps are carried out during
the fish hatchery operation
1.
The mature brood –stocks (male and female ) were
selected
2.
The were
separated in different tanks
3.
Ovaprim injection
were given to the female brood stocks
4.
Eggs were
stripped from the female fish after 9
hours
5.
The milt were also removed from the male
brood stocks
1.
Mixing of
eggs and milt (sperm) with the aid of
saline water in a small bowl
2.
Incubation of
fertilized eggs by laying the spawn net
at the bottom of the hatching tank which are held with stones at the edges
3.
Removal of the
spawn net when the fertilized eggs are
hatched after 3days
Siphoning: It is done manually with the aid
of a hose tied to
a long stick, to remove the dirt
and left over feeds at the bottom
of the tank. One side of the hose is
fixed inside the tank of water while the
other side of the hose is sucked with
the mouth in other to aid water
outlet.
The
dirt are removed alongside with the water
Tank scrubbing: in this experiments, foam is used to scrub walls of the tank gentle in
other to remove the slimy particles . It is carried out daily
Removal of short outs and mortalities: these experiment are done manually with a
scooping net to remove the shoot outs (over grown size
ones )and the dead ones
NOTE: mortalities are removed to avoid water pollution
Shoot
outs are removed so as to maintain the populations of fishes
FEEDING
Feeding is one
of the essential activity carried
out in the fisheries unit, inadequate
feeding can cause stunted growth and disease out break feeding is
normally carried out depending on the age, size and availability of feed
The table below are the feed requirement according to their ages
Age
|
Fish
stages
|
Feed
size (mm)
|
0-3days
|
Larva
|
Egg
yolk
|
2
weeks
|
Fryers
|
Artemia
(0.2mm)
|
4wks
|
Post
Fryers
|
0.5-0.9m
|
6wks
|
Fingerlins
|
0.8-1.2mm
|
8wks
|
Post
fingerlius
|
1.2-1.5mm
|
10wks
|
Juvenile
|
1.5mm-2mm
|
12wks
|
Post
juvenile
|
2mm-4mm
|
14wls
|
Table
size
|
4mm-above
|
NOTE: Fishes tend
to feed more on a cool weather
DISEASE ENCOUNTERED, CONTROL AND TREATMENT
1.
Tail rot: This is the
most disease suffered by the fish, the body tend to be peeling off. It is a fungi
disease
It
can be controlled by regular scrubbing and siphoning of the tank.
Treatment , mix
some quantity of OTC in their
feed and sun dry them, before feeding them to the
fishes or you can put 25g of salt
/100l of water in the tank
2. Infectious
dropsy: This is caused by bacterium pseudomonas
punctata. It can be prevented by
culling out of infected fishes in the
tank