66 MARCH 2014 • WORLD AQUACULTURE • WWW.WAS.ORG Epizootic Ulcerative Syndrome (EUS), caused mainly by the fungus Aphanomyces invadans, is one of the most destructive diseases among fresh- and brackishwater fish in the Asia-Pacific region. It is very common in northern and southern India, causing considerable losses to fish farmers. Ulcerative disease syndrome has been used to describe a group of cutaneous diseases of finfish (Hargis 1985). Among different ulcerative diseases, an EUS-like condition was first reported in the summer of 1971 in farmed ayu Plecoglossus altivelis in Oita Prefecture, Japan (Egusa and Masuda 1971). A similar disease was also reported in March 1972 from central Queensland, Australia, where several species of estuarine fish developed large shallow circular or irregular skin lesions termed ‘red-spot disease’ (Rodgers and Burke 1981). India witnessed the first major outbreak of EUS in 1988 in the states of Tripura, Assam, Meghalaya and West Bengal. It gradually spread, until 1992, to the states of Orissa, Bihar, Uttar Pradesh, Madhya Pradesh, Maharashtra, Andhra Pradesh, Tamil Nadu, Kerala, Karnataka and Haryana (Das 1997). It is very common in India and has spread through rivers, reservoirs and paddy fields (Muthukrishnan et al. 2008). In India, the Central Inland Fisheries Research Institute (CIFRI) has been monitoring the disease since early 1988. Epizootic Ulcerative Syndrome is the most commonly occurring deadly fish disease in northeast India, especially during the winter when water levels in fish ponds are reduced considerably. It occurs as a result of poor water quality in ponds. In winter, because of low water temperature, EUS spreads very easily. Control of EUS in wild populations is impossible in most cases. Selection of resistant species for culture purposes currently appears to be the most effective means of farm-level control. Use of Mikania cordata Extract to Control Epizootic Ulcerative Syndrome Disease in Tripura, India Debtanu Barman, Vikash Kumar, Suvra Roy, Kundan Kumar and K.V.Rajendran Where changing culture species is not an option, measures should be taken to eradicate or exclude the fungus, such as drying and liming of ponds prior to stocking, exclusion of wild fish, use of prophylactically-treated, hatchery-reared fry, use of groundwater, salt-bath treatments and disinfection of contaminated nets and equipment. Use of Mikania cordata to Control EUS Mikania cordata is native to Central and South America but is known as an invasive plant. It has spread to moist tropical and subtropical regions, including the northeast part of India where it is common in rural areas of Tripura. In rural tribal areas, fish farmers commonly apply extracts of Mikania cordata mixed with green turmeric juice and ash to control EUS in fish ponds. Green turmeric at 15-20 kg/ha is also effective. Applications are made at the beginning of winter and the monsoon season. Some fish farmers consider this method cost-effective and eco-friendly. The scientific pre-requisite for control of EUS is to make the water alkaline. Because ash makes the water alkaline, it may be useful in preventing EUS. The spread of EUS shows that it involves the role of an infectious agent in association with poor water quality. Thus, the application of Mikania cordata leaf extracts, ash and turmeric, which also has antimicrobial action, has been reported to control EUS to a great extent. Mikania cordata leaf extracts have shown promising positive results in controlling EUS in pond aquaculture as practiced in Tripura state. Hence, finding the chemical composition and active ingredients in Mikania cordata would be an immense help to farmers in treating EUS in a costeffective manner. (CONTINUED ON THE NEXT PAGE)
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