Because of financial problems, many carp farmers try to reproduce their fish by the
traditional method. Broodstock are released into special spawning ponds when the water
temperature exceeds 18 jC and weather conditions are appropriate. However, in many
cases, especially in Polish climatic conditions, the weather in late spring (May) is very
variable. The most dangerous phenomenon for carp farmers at that time is fluctuation of
air and water temperature and, especially, cold nights. These unfavourable conditions force
the carp farmers to delay (even for several weeks) the time of spawning in order to avoid a
risk of spawning failure. Delayed spawning, in turn, provokes the shortening of the
vegetation season and poorer fish production results in general. That is why we attempted
to induce natural spawning with the use of AZAGLY also in often seen unfavourable
temperature conditions for Polish carp farms. During the experiment, we observed
important fluctuations of water temperature (even if water supply was from the heating
pond, not from the river), with nocturnal drops of temperature down to approximately 14
jC. In all ponds with AZAGLY-treated fish (dose of 104 Ag/kg bw, maximal available at
the moment), prespawning behavior was observed, but final spawning took place only in
one pond where all females (n = 3) spawned successfully 48 h after injection of AZAGLY.
It should be noted that there were no signs of any prespawning activity in control ponds.
This indicates that the ‘‘joint action’’ of natural conditions (spawning substrate and the
presence of males) and AZAGLY treatment cannot fully overcome one key negative
factor—low water temperature
Because of financial problems, many carp farmers try to reproduce their fish by the
traditional method. Broodstock are released into special spawning ponds when the water
temperature exceeds 18 jC and weather conditions are appropriate. However, in many
cases, especially in Polish climatic conditions, the weather in late spring (May) is very
variable. The most dangerous phenomenon for carp farmers at that time is fluctuation of
air and water temperature and, especially, cold nights. These unfavourable conditions force
the carp farmers to delay (even for several weeks) the time of spawning in order to avoid a
risk of spawning failure. Delayed spawning, in turn, provokes the shortening of the
vegetation season and poorer fish production results in general. That is why we attempted
to induce natural spawning with the use of AZAGLY also in often seen unfavourable
temperature conditions for Polish carp farms. During the experiment, we observed
important fluctuations of water temperature (even if water supply was from the heating
pond, not from the river), with nocturnal drops of temperature down to approximately 14
jC. In all ponds with AZAGLY-treated fish (dose of 104 Ag/kg bw, maximal available at
the moment), prespawning behavior was observed, but final spawning took place only in
one pond where all females (n = 3) spawned successfully 48 h after injection of AZAGLY.
It should be noted that there were no signs of any prespawning activity in control ponds.
This indicates that the ‘‘joint action’’ of natural conditions (spawning substrate and the
presence of males) and AZAGLY treatment cannot fully overcome one key negative
factor—low water temperature
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