RESEARCH ON THE BREEDING OF THE PADDLEFISH, POLYODON SPATHULA WALBAUM, IN FISH POND POLYCULTURE
Elena Rada Misaila1, V. Vulpe2 and Lenuta Grigorica1
1“Alexandru Ioan Cuza” University, Research Station for Aquaculture and Aquatic Ecology, Iaşi, Romania
2”Ion Ionescu de la Brad” University of Agronomic Sciences and Veterinary, Medicine, Iaşi, Romania
Intensification of the fish production in Romania brought about modification in the formulas of fish breeding, the species with high economic value (such as the carp) being preferred by consumers, to the prejudice of Asian cyprinides.
Introduction in the culture of new species – such as the freshwater, Polyodon spathula Wal. assures a high upgrading of the natural trophic basis in the fish ponds. Paddlefish is a species that retains the zooplankton and the suspensions of organic nature.
Polyodon spathula Wal. comes from America. In 1990, it has been imported in Romania the first important alevine batch, obtained through artificial reproduction at the Station of Piscicultural Researches of Kisinev (Republic of Moldavia).
In the period 1991-2003, growing and survival of the P. spathula effective demonstrate its good adaptation capacity to the conditions provided in the aquatic basins from the Noth-Eastern part of Moldavia. The values of the water physico-chemical and biological parameters have favourized a suitable development of the paddlefish. Enriching of the trophic basis with the organic fertilizers during the vegetative period is necessary in the conditions of growing in policulture, an efficient conversion of the nutrients in the piscicultural biomass being noticed.
Sexual dimorphism is evident, the males having, at same age, lower dimensions (110 cm in length and 10.5 kg in weight), compared to the females (128-141 cm in length and 13-14.5 kg in weight).
For avoiding the occurrence of pathological incidents, a suitable preparation of the ponds and short-time bathings – occasioned by handling of the piscicultural material – are recommended.