Rezumatul tezei de doctorat - USAMV Cluj-Napoca

INTRODUCTION
Saprolegniasis is one of the most important causes of economic losses in aquaculture,
fungal infections are second only to bacterial diseases in economic importance. Fungal
infections are generally restricted to chronic, steady losses. Saprolegnia infests a large
number of teleosts, as: channel catfish, pike, bass, roach, carp, salmonids, sturgeon,
barramundi, tilapia; being associated with tropical fish: gourami, guppy, platyfish.
In Japan, there is an annual mortality rate of 50% in coho salmon (Oncorhynchus
kisutch) due to Saprolegnia parasitica Coker. Fifty percent per year losses have also been
reported in elver (Anguilla anguilla) culture in Japan. In Scotland, saprolegniasis causes
important economic losses especially in salmon fisheries. In the southeastern of United
States, major losses of 50% occur in channel catfish farming, and the economic loss of 40
million dollars.
In Romania, until now, there is not a scientific estimation of the fisheries losses due
to saprolegniasis.
CHAPTER I
EXPERIMENTAL HYPOTHESIS, RESEARCH OBJECTIVES,
EXPERIMENTAL DISPOSAL, MATERIAL AND METHOD
I.1. EXPERIMENTAL HYPOTHESIS AND RESEARCH OBJECTIVES
The bibliographic study on fish saprolegniasis in general, and particularly on carp
species, indicates the fact that in the world, because of the differences generated by the
diversity of water and soil types, by the medium annual temperatures, by the habitation
degree and by the existent fish species, the disease is generated by many species of
Saprolegnia, which have different specificity and pathogenicity, depending on the factors
listed above.
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