The microalgae Tetraselmis
chuii is part of the live foods used in the larval rearing of fish, crustaceans and molluscs. Its nutritional quality is closely related to culture media, with F/2
Guillard being the most widely used in aquaculture production centers. Fish waste silage can be an important alternative to commercial culture media as it contains high nutrient contents. In this study, the effect of partial and total replacement of the F/2 Guillard by chemical ensilage of fish waste on the growth of the microalgae T. chuii was evaluated.
Fish waste from the “canané” snapper (Ocyurus chrysurus) obtained from riverside fishermen from the port of Sisal, Yucatan, Mexico, was used. After being homogenized, formic acid was added at a ratio of 20 ml kg (v/p) and the initial pH and during the 30-day silage was recorded (Gallardo et al, 2012). The silage was carried out in triplicate using containers of 2 liters capacity.
Two bioassays of partial and total replacement of the F/2 Guillard medium were carried out, evaluating the population growth of T.chuii for 10 days under controlled conditions with 500 ml Erlenmeyer flasks. In the first experiment, seawater was fertilized at the beginning of the bioassay prior to inoculation. In the second bioassay, the silage was added on both day 0 and day 3 (Table 1).
A maximum value of concentration of T. chuii was observed on day 5 with treatments CT, A and B whose average value of 1.3 x 10-6 was much higher than that obtained when only the silage was used (0.5 x 106) (Fig. 1a). The results of experiment 2 show that the silage was beneficial for the growth of microalgae, allowing concentrations similar to those obtained with the commercial medium (Fig.1b).
Literature
Gallardo P., … ., and Sotelo A. 2012. Nutritive value of diets containing fish silage for juvenile Litopenaeus
vannamei (Bonne, 1931) . Journal of the Science of Food and Agriculture (DOI 10.1002/jsfa.5632). 2320 -2325.
Acknowledgments
This work was carried out with the support of the DGAPA-UNAM, Project PAPIIT IT 201611 under the responsibility of Dr. Pedro Gallardo