AUTOCHTHONOUS LIVE FUNGI AS GROWTH FACTORS IN LARVAE OF RHAMDIA QUELEN

MENDOZA, JORGE A.; GUIDOLI, MARCOS G.; HERNÁNDEZ, DAVID R.; BOEHRINGER, SILVIA I.; SÁNCHEZ, SEBASTIÁN; NADER MACÍAS, MARÍA E.

Botucatu

Simposio; SIMPÓSIO INTERNACIONAL DE NUTRIÇÃO E SAÚDE DE PEIXES AQUANUTRI; 2015

The native fish species are used in aquaculture production due to their resistance to the environmental conditions. The characteristics of the intensive culture system and the scarcity of bibliography generated a deficit in the number of animals. The use of antibiotics was used as an effective growth factor in the last decades. However, there is a worldwide tendency to reduce their use in animals for human consumption. One alternative used generally is the use of live microorganisms or probiotics. Previous results of our group allowed the isolation, identification and selection of putative autochthonous beneficial fungi: two Candida tropicalis (strains A and B), Candida lambrica (strain C) and a mold, Aureobasidium sp., (strain D). The objective of the present work was to evaluate the effect of the administration of different doses of these strains on biometrical parameters of Rhamdia quelen larvae. Then, 300 fecundated eggs were added in 5 liters plastic fish bowls with constant recirculation. Proposed treatments were strains A, B and C, administered in doses 6x104, 6x106 and 6x108 CFU L-1, the mold strain was administered in doses 6x102, 6x104 y 6x106 CFU L-1 and a control group without the addition of microorganisms. Administration during stage E (eggs) was performed four times a day in the water since the fecundation of the eggs until the beginning of exogenous feeding. In stage L (larvae), fish were feed four times a day with Artemia sp. previously incubated during two hours with the probiotic strains until day 15. At the end of the experiment larvae were counted and weighted to obtain survival, mean weight and biomass production of each treatment. Results did not show significant differences. The highest average values of mean weight, survival and biomass of animals administered with strain D were found in dose 6x104 CFU L-1. The highest average values of survival and biomass with strain C were obtained in dose 6x108 CFU L-1 and with strain B in dose 6x106 CFU L-1. Finally, the highest average values of survival with dose A were obtained with dose 6x104 CFU L-1. These results allowed us to select these doses as the most adequate to integrate a multi-strain formula containing two or more of these strains. Besides, these results showed, for the first time, the importance of the specie specificity concept in the development of a probiotic product for the aquaculture of native fish species.