64 JUNE 2013 • WORLD AQUACULTURE • WWW.WAS.ORG Among air-breathing freshwater food fishes, snakeheads (commonly called murrels in India) constitute the most common and dominant group. They fetch very high prices because the flesh quality is high in terms of taste and texture, with a low fat content, fewer intramuscular bones, and perceived medicinal value (Haniffa et al. 2004). The striped murrel Channa striata (Fig. 1) is a promising species for aquaculture in Asian countries but is constrained by the availability of seed and feed. Murrels are carnivorous, piscivorous and cannibalistic in nature. Murrels are affected by Epizootic Ulcerative Syndrome (EUS), primarily caused by the fungus Aphanomyces invadans and secondarily by the bacterium Aeromonas hydrophila (Karunasagar et al. 1995). Infection by A. hydrophila is generally associated with poor environmental conditions (Grabowshi et al. 2004). Invasion by the pathogen results in skin lesions that lead to high mortality. Common control measures of the diseases rely on antibiotics, chemotherapeutants and vaccines. However, using antibiotics for treatment is problematic, relating to the acquisition of genes that result in antibiotic-resistant strains of bacteria and Effect of a Probiotic and Herbal Additives on Growth, Survival and Disease Resistance of Striped Murrel M.A. Haniffa, B. Kavitha Bharathi, I. Viji Margaret and Bilal Ahmad Paray residues of antibiotics that ultimately diffuse into the aquatic environment (Ellis 1991, Smith et al. 1994). Application of modern tools is necessary to increase disease resistance and promote murrel aquaculture (Ghosh et al. 2002). An alternative and safer way to tackle Aeromonas infection is an eco-friendly development of resistance by the target species through application of probiotics (Ringo and Birkbeck 1999, Irianto and Austin 2002) and herbs (Guojun et al. 2008). These immunostimulants enhance the humoral and cellular immune responses in specific and non-specific ways, thereby reducing the risk of diseases. In the last few years probiotics and herbs have become an integral part of culture prevention for promoting growth and disease resistance. This strategy offers many advantages to overcome the limitations and side effects of antibiotics and other drugs and also leads to high production through enhanced growth and disease prevention (Das et al. 2008, Sahu et al. 2008). In aquaculture, the range of probiotics evaluated for use is considerably wider than in terrestrial agriculture. In the last few years probiotics and herbs have become an integral part of culture prevention for promoting growth and disease resistance. This strategy offers many advantages to overcome the limitations and side effects of antibiotics and other drugs and also leads to high production through enhanced growth and disease preventio. In aquaculture, the range of probiotics evaluated for use is considerably wider than in terrestrial agriculture. FIGURE 1. C. striatus affected by the disease Epizootic Ulcerative Syndrome. FIGURE 2. Feed additives and semi-moist feed.
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