Rezumatul tezei de doctorat - USAMV Cluj-Napoca

We mention the fact that in al the analyzed fisheries there is applied the annual
disinfection, in the fishponds where the natural supervised reproduction takes place,
emptying and keeping them dry on the winter period. Before the filling, the fishponds are
disinfected with lime at all of their surface. With all this, because of the reproduction
individuals manipulation and of the vegetation massive development, in the reproduction
period there are described strong attacks of pathogenic fungi upon spawns, with losses up to
70% in Ariniş fishery, and in the fisheries where the hygienic measures are very severe, the
losses are up to 20% from affected spawns (Cefa location). In average, in the 69 fishponds
from the 10 locations studied, the cyprinid spawn losses raise up to 41,10%. The larval
period, specially the first 3 days of life one, when their movements are limited by the
presence of vitelline membrane, the average losses raise up to 16,70%, with a 30%
maximum of losses, in Ariniş fishery, and a 5% minimum of losses in Cefa fishery. The
alevin period, extremely difficult as needs of water oxygen level and food quality, is strong
affected by saprolegniasis. The average losses of 7,60%, are more reduced compared to the
larval period. The biggest losses percentage at this category of age, is encountered in Iernut
fishery (13%), and a minimum of 5% in Ariniş, Ciurila, Daia, Cefa fishries.
In the young fish period, with its particular attention gived by the fishery owners
regarding the water and food quality, when there is assured an optimal density of the
individuals and the manipulations restricted, the losses caused by saprolegniasis are more
reduced, being in average of 4,90%.
The adult period is not safe from Saprolegnia attack. In the majority of the studied
fisheries, there is practiced the autumn fishing and the transfer of the kept fish for the next
year, in the wintering fishponds. The manual labor of catching, transportation and
repopulation in another fishpond causes body and fishfins inherent wounds. On the winter
period, the fish do not eat any food, their organism being weakened, and under the
influences of sudden temperature changes and ice layer, the losses are in average of 6,30%.
In springtime, the reproducers, as well as the fish kept for breeding, are verified regarding
their state maintenance and health, using fishing nets. The manipulation produces wounds,
which are causing the increase of saprolegniasis incidence, the average of the losses being of
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