Poster summaes
239
TRANSPORTATION OF LIVE CARP FRY IN SEALED POLYTHENE BACS.
D.R.T. SAMPSON, and
DJ.. MACINTOSH, =Ï.mtüîuic 05 Aqwcwtu/œ, Uniuc/1A1y 05 Si}Uuüng, SIX/tüng,
Scoîand, U.I<°
Transporting fish in sealed polythene bags with an atmosphere of pure oxygen
is_an extremely cheap and versatile method. It is increasingly common in
Southeast Asia, particularly for transporting fry and fingerlings. The
environment inside the bag is unique because it is a closed system, with an
extremely high
of dissolved oxygen,
in many cases a high stocking den—
sity (50—100 Kg/m ) and it only exists for a short duration. Consequently
tolerance
levels measured for fish as LG
0
over
a
24 or 48hr period are of
limited use for interpreting water qualiëy changes occuring inside the bag.
Moreover
interactions between the various parameters can take place at levels
not
normally found in the natural environment. Theoretical considerations for
calculating stocking densities that can be used for different species and
sizes of fish at any particular temperature will be difficult to apply to
practical situations, since the survival of fish during transport depends to
a
large extent on their pre—packing condition. The condition of the fish to
be transported depends on the feeding state and on any damage incurred during
handling. Specific practical problems of using the polythene bag method do
occur
not
least the availability of suitable bags and oxygen, as well as a
clean water supply. Even when these are available mortalities still occur in
significant numbers. Often this is attributable to the rapid changes in tem—
perature that can occur.
Steps are being taken to rectify this problem
through the use of insulated containers.
FEEDING OF CAR?
(Cyprinus carpio) LARVAE WITH AN ARTIFICIAL DRY FOOD, LIVING
ZOOPLANKTON AND MIXED FOOD. M. SZLAMINSKA and A. PRZVBVL, Dep…memä 05
BÂO cnMgotéœ, IMMwC 05 Ecolîogy, Dzchzan0w Lamy n/Wwwaw,
05—092 LOMÏANKÏ, P0£and.
We wished to determine if the artificial was as nutritive as zooplankton,
so
it could replace zooplankton in the case of an insufficiency. Three day
old larvae were fed for
7 d with an artificial encapsulated diet (Przybyl's
recipe : main component lyophylised pork liver) and with live zooplanktgn.
The fish were reared at the2temperature
of
24°C in PCV aquaria of 13 dm
cap—
acity
surface
11
dm ); the stocking rate was 760 indiv. and the flow
rate
0,38 dm /min. The experimental design was a factorial 3 x 3 experiment
a) threelevels of feeding were given daily every 15 mn for 3 h (6:00—9:00)
1000 dry food particles/dm2 i;e. "optimum"density) and no dry food. b) three
levels of zooplankton were give daily for 12 hours (9:00—21z00) "ad libitum"
level, restricted (half of "ad libizum") level and no zooplankton. Therefore
the 9 experimental groups were : starved (1), fed dry food only (2), zooplankton only (2) or mixed food (4) each in duplicate. The differences between
the duplicates were negligible. The survival rate of fed fish was 90% or more
but it was 61% for the starved ones. The specific growth rate of weight (SCR)
ranged from 7,2%/d (”start of feeding "level of dry food) to 29,6%/d (mixed
food
:
”optimum"level of dry food and ”ad libitum” level of aooplankton).
In the
group of
starved fish weight loss was observed (negative
SGR
—8,IZ/d). High survival and growth rates indicated that experimental condi—
tions were favourable. The best final weight (table 1) were recorded
ÎlSh"
fed the mixed food
:
"optimum” level of dry food and
"ad 11b1tum
'
Those fed with the 2nd type of mixed food ("start of feeding
leve1_0f dry
food and "ad 1ibitum" level of zooplankton) grew a little slower. Fish
With two levels of dry food and zooplankton grew more slowly,
the duplication
of
level of dry food didn't accelerate significantly the flSh growth. The
final weight (mg) of fish fed with dry food only and zooplankton only compa—
239
TRANSPORTATION OF LIVE CARP FRY IN SEALED POLYTHENE BACS.
D.R.T. SAMPSON, and
DJ.. MACINTOSH, =Ï.mtüîuic 05 Aqwcwtu/œ, Uniuc/1A1y 05 Si}Uuüng, SIX/tüng,
Scoîand, U.I<°
Transporting fish in sealed polythene bags with an atmosphere of pure oxygen
is_an extremely cheap and versatile method. It is increasingly common in
Southeast Asia, particularly for transporting fry and fingerlings. The
environment inside the bag is unique because it is a closed system, with an
extremely high
of dissolved oxygen,
in many cases a high stocking den—
sity (50—100 Kg/m ) and it only exists for a short duration. Consequently
tolerance
levels measured for fish as LG
0
over
a
24 or 48hr period are of
limited use for interpreting water qualiëy changes occuring inside the bag.
Moreover
interactions between the various parameters can take place at levels
not
normally found in the natural environment. Theoretical considerations for
calculating stocking densities that can be used for different species and
sizes of fish at any particular temperature will be difficult to apply to
practical situations, since the survival of fish during transport depends to
a
large extent on their pre—packing condition. The condition of the fish to
be transported depends on the feeding state and on any damage incurred during
handling. Specific practical problems of using the polythene bag method do
occur
not
least the availability of suitable bags and oxygen, as well as a
clean water supply. Even when these are available mortalities still occur in
significant numbers. Often this is attributable to the rapid changes in tem—
perature that can occur.
Steps are being taken to rectify this problem
through the use of insulated containers.
FEEDING OF CAR?
(Cyprinus carpio) LARVAE WITH AN ARTIFICIAL DRY FOOD, LIVING
ZOOPLANKTON AND MIXED FOOD. M. SZLAMINSKA and A. PRZVBVL, Dep…memä 05
BÂO cnMgotéœ, IMMwC 05 Ecolîogy, Dzchzan0w Lamy n/Wwwaw,
05—092 LOMÏANKÏ, P0£and.
We wished to determine if the artificial was as nutritive as zooplankton,
so
it could replace zooplankton in the case of an insufficiency. Three day
old larvae were fed for
7 d with an artificial encapsulated diet (Przybyl's
recipe : main component lyophylised pork liver) and with live zooplanktgn.
The fish were reared at the2temperature
of
24°C in PCV aquaria of 13 dm
cap—
acity
surface
11
dm ); the stocking rate was 760 indiv. and the flow
rate
0,38 dm /min. The experimental design was a factorial 3 x 3 experiment
a) threelevels of feeding were given daily every 15 mn for 3 h (6:00—9:00)
1000 dry food particles/dm2 i;e. "optimum"density) and no dry food. b) three
levels of zooplankton were give daily for 12 hours (9:00—21z00) "ad libitum"
level, restricted (half of "ad libizum") level and no zooplankton. Therefore
the 9 experimental groups were : starved (1), fed dry food only (2), zooplankton only (2) or mixed food (4) each in duplicate. The differences between
the duplicates were negligible. The survival rate of fed fish was 90% or more
but it was 61% for the starved ones. The specific growth rate of weight (SCR)
ranged from 7,2%/d (”start of feeding "level of dry food) to 29,6%/d (mixed
food
:
”optimum"level of dry food and ”ad libitum” level of aooplankton).
In the
group of
starved fish weight loss was observed (negative
SGR
—8,IZ/d). High survival and growth rates indicated that experimental condi—
tions were favourable. The best final weight (table 1) were recorded
ÎlSh"
fed the mixed food
:
"optimum” level of dry food and
"ad 11b1tum
'
Those fed with the 2nd type of mixed food ("start of feeding
leve1_0f dry
food and "ad 1ibitum" level of zooplankton) grew a little slower. Fish
With two levels of dry food and zooplankton grew more slowly,
the duplication
of
level of dry food didn't accelerate significantly the flSh growth. The
final weight (mg) of fish fed with dry food only and zooplankton only compa—