R. Billard et J. Marcel, Ed. Aquaculture of Cyprinids, INRA, Paris, 1986.
Pester summanes
INTENSIVE FISH CULTURE IN CIRCULATED FONDS.
V. AVNIMELECH, B. WEBER, B. HEPHER
and A. MILSTEIN, 30436 and Nate/r R@mch Genie/1, Facuüy 05 AgMc.Eng.,
TcchMan IMde IMÜ'ÆuÆc 05 Tcchno£ogg,
32000, ISRAEL.
Studies wgre
done
in 3 sets of circulated ponds,
]
m3 tanks, 10 m3 miniponds
and
200 m
ponds. In all cases water was continually circulated and aerated,
sediments resuspended and the non—resuspended fraction drained daily. Several
features were
typical to those systems : 1) the metabolism of organic matter
was
more
effective than in conventional ponds. Only 10% of the added carbon
or
nitrogen was drained out as compared to 302 accumulation in the sediments
of conventional ponds. 2) unlike conventional ponds, nitrogen is rapidly
nitrified and accumulates as NO _. When anaerobic microenvironments are
present nitrogen is lost througä denitrification. 3) fish growth seems to be
correlated with a complete oxidation of the pond and is slowed by the presence
of anaerobic pockets. 4) very low C/N ratios are developing due to the effect—
ive removal of carbon and the accumulation of nitrates. The nitrogen can be
tied to added carboneceous materia
ls
as
microbial proteins.
EFFECTS OF SUBLETHAL CONCENTRATIONS OF TEXTILE INDUSTRY EFFLUENT ON FOOD
UTILISATION AND GROWTH IN Cyprinus carpio. M.P. BALASUBRAMÀNÏAN, S.EZHILARASI,
S. ARUNACHALAM and M.R. RAJAN, P.G. @@ RQÀQCUM‘JŒ Dcpæuüncmä 05 Zoo£ogy,
PMaM 624602 Tamüî Nadu, INDIA.
The present investigation reports the effects of textile industry effluents
on
the survival of carp and its food consumption, growth and conversion ef—
ficiency at different sub—lethal concentrations of the effluents. The food
consumption of carp reared in effluent—free water and at 2% concentration of
the effluent were
21.62 and 22.84 mg of dry food/g of live fish/day, respecti—
vely. But at higher concentrations, food consumption decreased. Growth was
reduced from 3.1
to
2.9 mg of dry food/g of live fish/day when the carp were
reared in a 22 effluent but at higher concentrations (4%), negative growth
was
found which increased with increasing concentration of the effluents. The
role of enzymes
for food utilisation and growth is important. Hence, the effe—
ct
of
the effluent on the phosphatases and esterases of fishes reared at
different sub—lethal concentrations were also studied biochemically, using
p—nitrophenyl ph03phate and 1 — napthyl acetate as substrates.
CONTINOUS RECORDING OF PHYSICOCHEMICAL AND METEOROLOGICAL PARAMETERS IN FONDS.
V.GINOT, M.G. HOLLEBECQ, O. LANGLOIS, R. BILLARD and M. VUILLOT, INRA, DepaÆI—
ment 06 HydûobÀa£àgy, 78350 JOUY EN JOSAS, FRANCE.
Technical data obtained in experimental stations cannot be adequately amd
directe1y communicated to aquaculturists for management of pond fish culture
because there are few systems in use for measuring and controlling continou—
Sly the environmental parameters of ponds. This new system measures and keeps
the major physicochemical (pH, dissolved oxygen, temperature, conductivity)
and meteorological (speed and wind direction, pluviometry, pyranometer, air
temperature) parameters in memory (RAM). The power autonomy of the whole
System is
15
days with a battery. The parameters recording interval can be
Pester summanes
INTENSIVE FISH CULTURE IN CIRCULATED FONDS.
V. AVNIMELECH, B. WEBER, B. HEPHER
and A. MILSTEIN, 30436 and Nate/r R@mch Genie/1, Facuüy 05 AgMc.Eng.,
TcchMan IMde IMÜ'ÆuÆc 05 Tcchno£ogg,
32000, ISRAEL.
Studies wgre
done
in 3 sets of circulated ponds,
]
m3 tanks, 10 m3 miniponds
and
200 m
ponds. In all cases water was continually circulated and aerated,
sediments resuspended and the non—resuspended fraction drained daily. Several
features were
typical to those systems : 1) the metabolism of organic matter
was
more
effective than in conventional ponds. Only 10% of the added carbon
or
nitrogen was drained out as compared to 302 accumulation in the sediments
of conventional ponds. 2) unlike conventional ponds, nitrogen is rapidly
nitrified and accumulates as NO _. When anaerobic microenvironments are
present nitrogen is lost througä denitrification. 3) fish growth seems to be
correlated with a complete oxidation of the pond and is slowed by the presence
of anaerobic pockets. 4) very low C/N ratios are developing due to the effect—
ive removal of carbon and the accumulation of nitrates. The nitrogen can be
tied to added carboneceous materia
ls
as
microbial proteins.
EFFECTS OF SUBLETHAL CONCENTRATIONS OF TEXTILE INDUSTRY EFFLUENT ON FOOD
UTILISATION AND GROWTH IN Cyprinus carpio. M.P. BALASUBRAMÀNÏAN, S.EZHILARASI,
S. ARUNACHALAM and M.R. RAJAN, P.G. @@ RQÀQCUM‘JŒ Dcpæuüncmä 05 Zoo£ogy,
PMaM 624602 Tamüî Nadu, INDIA.
The present investigation reports the effects of textile industry effluents
on
the survival of carp and its food consumption, growth and conversion ef—
ficiency at different sub—lethal concentrations of the effluents. The food
consumption of carp reared in effluent—free water and at 2% concentration of
the effluent were
21.62 and 22.84 mg of dry food/g of live fish/day, respecti—
vely. But at higher concentrations, food consumption decreased. Growth was
reduced from 3.1
to
2.9 mg of dry food/g of live fish/day when the carp were
reared in a 22 effluent but at higher concentrations (4%), negative growth
was
found which increased with increasing concentration of the effluents. The
role of enzymes
for food utilisation and growth is important. Hence, the effe—
ct
of
the effluent on the phosphatases and esterases of fishes reared at
different sub—lethal concentrations were also studied biochemically, using
p—nitrophenyl ph03phate and 1 — napthyl acetate as substrates.
CONTINOUS RECORDING OF PHYSICOCHEMICAL AND METEOROLOGICAL PARAMETERS IN FONDS.
V.GINOT, M.G. HOLLEBECQ, O. LANGLOIS, R. BILLARD and M. VUILLOT, INRA, DepaÆI—
ment 06 HydûobÀa£àgy, 78350 JOUY EN JOSAS, FRANCE.
Technical data obtained in experimental stations cannot be adequately amd
directe1y communicated to aquaculturists for management of pond fish culture
because there are few systems in use for measuring and controlling continou—
Sly the environmental parameters of ponds. This new system measures and keeps
the major physicochemical (pH, dissolved oxygen, temperature, conductivity)
and meteorological (speed and wind direction, pluviometry, pyranometer, air
temperature) parameters in memory (RAM). The power autonomy of the whole
System is
15
days with a battery. The parameters recording interval can be