Conciuding remar£rs
173
organic manures (cow—dung and poultry manure) on the survival of carp eggs
and hatchings and hatchebility have also been evaluated. Their threshhold
values and safe releasing limits have been determined.
FISH BREEDING UNDER CONTROLLED ENVIRONMENT — CARP HATCHERY CIFE D—81. S.N.
ÛWÏVEDÏ and À.K. REÛÜV, Ceniäa£ ÏHAÆÀÆuÉQ 06 FÀAhQäÀQA EduQŒÉÀOn (Ï.C.À.R.)
Ve}v50va, Bombay 400 067, INDIA.
Environmental parameters
like temperature, oxygen, pH, water current and
gilt content are the major constraints in the fish breeding and hatching.
Therefore, an attempt has been made by Central Institute of Fisheries
Education (CIFE), Bombay to develop a system in which these environmental
parameters can be controlled. In this system holestic approach has been
adopted and favourable environment present in the flowing waters has been
simulated. Finally, success has been achieved designing a carp hatchery
model
CIFE
D—8O and D—81, during the years 1980 and 1981 respectively. Now
it has been possible to breed fish irrespective of climatic conditions. These
hatcheries have been installed and demonstrated in different parts of India.
The breeding and hatching success were enhanced to about 99%. A brief account
of the experiments conducted and their success at Khutela Bhata (M.P.),
Damdama
(Haryana) and Aarey (Maharashtra) is presented. The system is com—
mercially viable and can be operated in any place with assured success.
Conelsdmg remarks
The majority of the communications presented at the oral and posters ses—
sions could be grouped around two important
problems concerned with the cul—
ture of
carp
and related species, namely, the effects of the environment and
spawning induction. These problems were dealt with at both the practical and
the theoretical levels.
It was
only natural to focus the round table discus—
sion around these problems.
]. Effect of some environmental factors
All
the relevant presentations have indicated that temperature is the
main external factor affecting reproduction in cyprinids. Although the col—
lection of papers presented at the symposium has not encompassed any paper on
photoperiodic effects, there is enough evidence to show that the photoperiod
does affect reproduction in some cyprinids like the goldfish, in which there
is an interaction between photoperiod and temperature. However, carp, even
maintained on a constant light or constant dark regimes, do respond, by gona—
dal recrudescence, to an increase in the temperature (Horvath).
The significance of the ”amount of temperature” as related to carp repro—
duction was emphasized by Horvath. He recommended the determination
of
"degree days” to which the fish are exposed in order to predict the proper
ndng of Spawning in carps. This term, which represents the multiplication
Of temperature by days, was challanged by Bieniarz and by K1me on the grounds
that it does not fully reflect the complex situation of temperature effects
on
carp reproduction. The term may be useful only within
the
limits of optimal
temperatures, especially when it implicates the definition of a critical tem—
perature
(Bieniarz). This is in agreement with the
fact that gametogeneSis
d0€s not occur in carp at a temperature below 15 C (HOÏYaÏh)'
The possible
_
Ï01e of daily fluctuation in the temperature was also discussed, espec1ally ln
173
organic manures (cow—dung and poultry manure) on the survival of carp eggs
and hatchings and hatchebility have also been evaluated. Their threshhold
values and safe releasing limits have been determined.
FISH BREEDING UNDER CONTROLLED ENVIRONMENT — CARP HATCHERY CIFE D—81. S.N.
ÛWÏVEDÏ and À.K. REÛÜV, Ceniäa£ ÏHAÆÀÆuÉQ 06 FÀAhQäÀQA EduQŒÉÀOn (Ï.C.À.R.)
Ve}v50va, Bombay 400 067, INDIA.
Environmental parameters
like temperature, oxygen, pH, water current and
gilt content are the major constraints in the fish breeding and hatching.
Therefore, an attempt has been made by Central Institute of Fisheries
Education (CIFE), Bombay to develop a system in which these environmental
parameters can be controlled. In this system holestic approach has been
adopted and favourable environment present in the flowing waters has been
simulated. Finally, success has been achieved designing a carp hatchery
model
CIFE
D—8O and D—81, during the years 1980 and 1981 respectively. Now
it has been possible to breed fish irrespective of climatic conditions. These
hatcheries have been installed and demonstrated in different parts of India.
The breeding and hatching success were enhanced to about 99%. A brief account
of the experiments conducted and their success at Khutela Bhata (M.P.),
Damdama
(Haryana) and Aarey (Maharashtra) is presented. The system is com—
mercially viable and can be operated in any place with assured success.
Conelsdmg remarks
The majority of the communications presented at the oral and posters ses—
sions could be grouped around two important
problems concerned with the cul—
ture of
carp
and related species, namely, the effects of the environment and
spawning induction. These problems were dealt with at both the practical and
the theoretical levels.
It was
only natural to focus the round table discus—
sion around these problems.
]. Effect of some environmental factors
All
the relevant presentations have indicated that temperature is the
main external factor affecting reproduction in cyprinids. Although the col—
lection of papers presented at the symposium has not encompassed any paper on
photoperiodic effects, there is enough evidence to show that the photoperiod
does affect reproduction in some cyprinids like the goldfish, in which there
is an interaction between photoperiod and temperature. However, carp, even
maintained on a constant light or constant dark regimes, do respond, by gona—
dal recrudescence, to an increase in the temperature (Horvath).
The significance of the ”amount of temperature” as related to carp repro—
duction was emphasized by Horvath. He recommended the determination
of
"degree days” to which the fish are exposed in order to predict the proper
ndng of Spawning in carps. This term, which represents the multiplication
Of temperature by days, was challanged by Bieniarz and by K1me on the grounds
that it does not fully reflect the complex situation of temperature effects
on
carp reproduction. The term may be useful only within
the
limits of optimal
temperatures, especially when it implicates the definition of a critical tem—
perature
(Bieniarz). This is in agreement with the
fact that gametogeneSis
d0€s not occur in carp at a temperature below 15 C (HOÏYaÏh)'
The possible
_
Ï01e of daily fluctuation in the temperature was also discussed, espec1ally ln