170
Aquaculture of Cyprinids
EFFECTS OF SOME POLLUTANTS
(COPPER SULPHATE AND ZINC SULPHATE) ON THE OOGE—
NETIC STAGES OF AN INDIAN MAJOR CARE, Labeo rohita (HAM.). C.K. PATHAK,
Dcpthcmi 05 Zoo£ogy, Sauga}z UMuQ/æiig, Saga/r (MP.), INDIA.
The
toxic effects of two heavy metal salts (copper sulphate and zinc sulph—
ate) on the oogenetic stages of Labeo rohita has been investigated. Fifty
fishes
(ranging between 15 and 20 cm in lenght) were procured from Sagar
lake and acclimatized in different aquaria for ten days (lst week of MardÙ
at
the
temperature of 26 i 3°C. The experiment was conducted in two phases.
In the first phase the fishes were kept in different strong concentrations
of pollutants and their turn over time was noted (14 hours in 20 ppm copper
sulphate and 18 hours in 100 ppm.zinc sulphate). Keeping these observations
in mind, rest of the'fishes were divided into different grades of more
diluted solutions of pollutants and their survival time was noted. At sub—
lethal
concentrations of 2 ppm.copper sulphate and 20 ppm zinc sulphate,
the
fish survived for a long period and, as such, these concentrations were
used in the second phase of the experiment. Four females were sacrified at
the onset of
the
experiment (initial controls) and their gonads were fixed
in aqueous Bouin and Holland‘s modified Bouin. The lenght of the fish,body
weight, gonad weight and volume were recorded. Ten fish were kept as control.
The pollutant solutions were changed daily so as to maintain their level
of
concentration. The fish from the different experimental groups were sacrificed on day 40 of the experiment. Sections of the ovary were cut at 6 pm
and stained in Ehrlich's acid alum haemotoxylin eosin. The ovary of the
initial control fish exhibited a typical teleostean pattern. The ovarian
wall is
thin and the ovigerous lamellae indistinct. Oocytes of early and
late yolk vesicle stages outnumbered others. In 40—day control fish, the
ovary
contained most of the oogenetic stages with a few corpora atretica
in various stages of absorption. In comparaison to the control fish, the
ovarian wall of pollutant treated fish was thick and the ovigerous lamellae
distinct; a good number of advanced—stage oocytes had undergone atresia. A
few oocytes,
specially of fish treated with copper sulphate were pycknotic
showing vacuolisation in the cytoplasm. Masses of free blood cells were
accumulated around the
oocytes. The effect of copper sulphate was more
pronounced. The effects of these pollutants were also assessed quantitatively in respect of the GSI, which was 10 in the initial control, showing
gonadal activity and high metabolism. These values decreased a little in
the 40 day control fish and sharply after the 40 days pollutant treatment
(5.3
and 2.3 in the case of zinc and copper sulphate regpectively) indica—
ting a sharp downward trend in gonadal activity.
EFFECT OF STOCKING AND FEED QUANTITY ON THE BROODSTOCK OF CARE AND RELATED
SPECIES.
A. PETERÏ, À. RUTTKÀV) L. HORVÀTH, A. ZSÏGRÏ, I. CSENGËRÏ,aHd CA.
ZSIGRI, H. 5540, SZŒÆUŒA HUNGÀRV
Egg production in common carp (C.c), silver carp (S.c.), bighead, grass
carp and silurus broodstock populations ofter varies due to the unclear
effects
of broodstock rearing technologies. We studied the effect of sto—
ck1ng and feeding on the net production and the development of eggs in
broodstock candidates and on the egg production of mature fighes reared in
polycultural ponds fertilized intensively. The C.c. were fed on wheat and
P8118t8 (242 protein content) at a ratio of 45:55. The net production (N)
of
C.c.
broodstock candidates depended On the stocking weight (x) and feed
quantity (y), according to the equation :
N =
8
X
(y + yo)
+
c
x
Aquaculture of Cyprinids
EFFECTS OF SOME POLLUTANTS
(COPPER SULPHATE AND ZINC SULPHATE) ON THE OOGE—
NETIC STAGES OF AN INDIAN MAJOR CARE, Labeo rohita (HAM.). C.K. PATHAK,
Dcpthcmi 05 Zoo£ogy, Sauga}z UMuQ/æiig, Saga/r (MP.), INDIA.
The
toxic effects of two heavy metal salts (copper sulphate and zinc sulph—
ate) on the oogenetic stages of Labeo rohita has been investigated. Fifty
fishes
(ranging between 15 and 20 cm in lenght) were procured from Sagar
lake and acclimatized in different aquaria for ten days (lst week of MardÙ
at
the
temperature of 26 i 3°C. The experiment was conducted in two phases.
In the first phase the fishes were kept in different strong concentrations
of pollutants and their turn over time was noted (14 hours in 20 ppm copper
sulphate and 18 hours in 100 ppm.zinc sulphate). Keeping these observations
in mind, rest of the'fishes were divided into different grades of more
diluted solutions of pollutants and their survival time was noted. At sub—
lethal
concentrations of 2 ppm.copper sulphate and 20 ppm zinc sulphate,
the
fish survived for a long period and, as such, these concentrations were
used in the second phase of the experiment. Four females were sacrified at
the onset of
the
experiment (initial controls) and their gonads were fixed
in aqueous Bouin and Holland‘s modified Bouin. The lenght of the fish,body
weight, gonad weight and volume were recorded. Ten fish were kept as control.
The pollutant solutions were changed daily so as to maintain their level
of
concentration. The fish from the different experimental groups were sacrificed on day 40 of the experiment. Sections of the ovary were cut at 6 pm
and stained in Ehrlich's acid alum haemotoxylin eosin. The ovary of the
initial control fish exhibited a typical teleostean pattern. The ovarian
wall is
thin and the ovigerous lamellae indistinct. Oocytes of early and
late yolk vesicle stages outnumbered others. In 40—day control fish, the
ovary
contained most of the oogenetic stages with a few corpora atretica
in various stages of absorption. In comparaison to the control fish, the
ovarian wall of pollutant treated fish was thick and the ovigerous lamellae
distinct; a good number of advanced—stage oocytes had undergone atresia. A
few oocytes,
specially of fish treated with copper sulphate were pycknotic
showing vacuolisation in the cytoplasm. Masses of free blood cells were
accumulated around the
oocytes. The effect of copper sulphate was more
pronounced. The effects of these pollutants were also assessed quantitatively in respect of the GSI, which was 10 in the initial control, showing
gonadal activity and high metabolism. These values decreased a little in
the 40 day control fish and sharply after the 40 days pollutant treatment
(5.3
and 2.3 in the case of zinc and copper sulphate regpectively) indica—
ting a sharp downward trend in gonadal activity.
EFFECT OF STOCKING AND FEED QUANTITY ON THE BROODSTOCK OF CARE AND RELATED
SPECIES.
A. PETERÏ, À. RUTTKÀV) L. HORVÀTH, A. ZSÏGRÏ, I. CSENGËRÏ,aHd CA.
ZSIGRI, H. 5540, SZŒÆUŒA HUNGÀRV
Egg production in common carp (C.c), silver carp (S.c.), bighead, grass
carp and silurus broodstock populations ofter varies due to the unclear
effects
of broodstock rearing technologies. We studied the effect of sto—
ck1ng and feeding on the net production and the development of eggs in
broodstock candidates and on the egg production of mature fighes reared in
polycultural ponds fertilized intensively. The C.c. were fed on wheat and
P8118t8 (242 protein content) at a ratio of 45:55. The net production (N)
of
C.c.
broodstock candidates depended On the stocking weight (x) and feed
quantity (y), according to the equation :
N =
8
X
(y + yo)
+
c
x