Delivering
bioactive compounds to fish larvae using microencapsulated diets
M. Yúfera, S. Kolkovski, C. Fernández-Díaz, J.
Rinchard, K.J. Lee, K. Dabrowski
Aquaculture, 227(1-4): 277-291
Abstract:
The efficient delivery of nutrients and hormones has
special relevance to the development of rearing technologies for fish larvae
and juveniles. The main aim is to find an effective and measurable way to
administer them into the body of small aquatic animals. In this study, three
different compounds (hormones, amino acids, and vitamins) were incorporated
into protein-walled microencapsulated diets. Specifically these
microencapsulated diets were examined for (a) the kinetics of incorporation
of estradiol in Sparus aurata larvae, (b) absorption and leaching
patterns of the free amino acids (FAA), and (c) growth results and tissue
incorporation of vitamins in relation to the supplementation of vitamin C in
larvae of S. aurata and Solea senegalensis. The efficiency of
inclusion was relatively low, but the capsules were able to retain enough of
these compounds when immersed in water and to deliver them into the
digestive tract of the larvae. There are noticeable differences among the
nominal amount of a given substance in the ingredient mixture, the actual
amount in the microparticle and the amount delivered in the larval gut. It
is therefore necessary to examine carefully whether the ingredient is
reaching the digestive tract for achieving suitable conclusions in
nutritional studies. These results indicate the applicability of these
microencapsulated particles in nutritional studies of small aquatic animals.
(Instituto de Ciencias Marinas de Andalucía (CSIC),
Apartado Oficial, Puerto Real, Cadiz 11510, Spain, e-mail: manuel.yufera@icman.csic.es)