University of Agricultural Sciences and Veterinary Medicine Iasi - 250 - THE USE OF PHYTOBIOTICS IN AQUACULTURE V. Cristea 1* , Alina Antache 1 , Iulia Grecu 1 , Angela Docan 1 , Lorena Dediu 1 , Mirela (Creţu) Mocanu 1 1 University "Dunărea de Jos" Galati, Romania Abstract The purpose of this paper was to summarize and evaluate current knowledge of phytobiotics use and action in fish culture, and their potential to be applied further in aquaculture production, because, in recent years, the fish consumption increased and total world production of fish has decreased. The main cause of the decrease fish production is the occurrence of diseases caused by different pathogens. The need for enhanced disease resistance, feed efficiency, and growth performance of cultured organisms is substantial for various sectors of this industry. It is preferable that, in the case of commercial aquaculture, the costs production to be reduced. Because the cost of antibiotics used for prevention and treatment of disease, and hormones used for growth performance is high, and from the desire to search for new options, several studies have been carried out to test new compounds, from which the aquaculture industry has developed the concept of „functional additives”. This category includes also phytobiotics. Thus, it was proved that their use in fish diet led to improvement of the innate immune system for infection with various bacteria (Aeromonas hydrophila in particular) in different species of fish. In conclusion are needed further studies to find out the effective use of various phytobiotics with special reference to the timing, dosage, and method of administration. Key words: phytobiotics, aquaculture, innate immunity, Aeromonas hydrophila, growth performance INTRODUCTION 1 The aquaculture sector has been expanding at an average compounded rate of 9.2% per year since 1970, compared with only 1.4% for capture fisheries and 2.8% for terrestrial- farmed meat production systems. With the increasing intensification and commercialization of aquaculture production, infectious diseases are a major problem causing heavy loss to the fish farming industry [3]. The recent expansion of intensive aquaculture practices has led to high interest in understanding the various fish diseases, so that they can be treated or prevented. It is widely demonstrated that the occurrence of diseases in fish farm is due to several factors concerned with the rearing methods, environmental conditions and variations. Consequently, cultivated fish can become more susceptible not only to pathogenic but also to opportunistic bacteria [34]. *Corresponding author: antache_alina@yahoo.com The manuscript was received: 04.04.2012 Accepted for publication: 20.04.2012 Because, in intensive aquaculture, the use of antibiotics and chemotherapeutics for treatment and prophylaxis has been broadly criticized for its negative impact, and research on interactions between growth, immunity and development of eco-friendly alternatives to antibiotics that may keep fish healthy such as probiotics and plant based immunostimulants has increased, indigenous technological knowledge for treating diseases is enjoying attention in fish health and disease management [27]. In addition, the global demand for safe food has prompted the search for natural alternative growth promoters to be used in aquatic feeds. There has been heightened research in developing new dietary supplementation strategies in which various health and growth promoting compounds as probiotics, prebiotics, synbiotics, phytobiotics and other functional dietary supplements have been assessed [8]. In concerning evaluation of phytobiotics in aquaculture is a relatively new area of research showing promising results.