Indian Journal of Experimental Biology Vol. 42, November 2004, pp. 1073-1077 Immunomodulation by 'ImmuPlus (Aqualmmu)' in giant freshwater prawn, Macrobrachium rosenbergii (De Man) Jaya Kumari, P K Sahoo*, S S Giri & Bindu R Pillai Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar 751 002, India Received 24 November 2003; revised 12 August 2004 ImmuPius, a polyherbal commercial formulation was used to modulate the immune system of commercially important giant freshwater prawn M. rosenbergii. The prawns were fed with basal diet supplemented with ImmuPius@ lg/kg feed for 4 weeks. Results showed that the phenoloxidase activity (PO), haemagglutination and lysozyme activities were significantly elevated in lmmuPius-fed prawn up to 3 weeks of feeding and declined after 4 weeks of feeding. The total protein level in lmmuPius-fed prawn raised up to 2"d week of feeding. Incorporation of ImmuPlus at the rate of lg/kg feed in the diet of prawn for 3 weeks may be beneficial in raising the immune status of prawn. Keywords: Macrobrachiwn rosenbergii, Immunomodulation, ImmuPius The giant freshwater prawn, Macrobrachium rosenbergii (De Man), is commercially important worldwide as a primary inland cultured species 1 • However, the disease outbreaks caused by the pathogens and environmental stress result in declined production. A major constraint in the commercial scale aquaculture production of this species is the inadequate availability of seed 2 . The serious effect of infections in wild stock are most probably underestimated as the diseased animals rapidly vanish in nature, and only in aquacultural farms mortality are reported causing economic Joss 3 . Although the freshwater prawns are comparatively resistant than brackishwater shrimps, they are not free from diseases. Shell diseases such as Brown and Black spot caused by bacteria and vibriosis are commonly found in adult prawns 4 . Further, high stocking density in culture system aggravates the infections. Studies towards a better understanding of prawn defense mechanisms constitute one approach towards overcoming di sease problems. Many workers have tried to study how shrimp defence factors, including possible induction mechanisms, influence shrimp health and resistance to disease, but the information gained has not yet Jed to any general conclusions. One problem may be the lack of reliable and effective *Correspond e nt author: Phon e: +91-674-2465421 ; Fa x: +91-674-2465407 E-mail: pk sahoo I @hotmail.com indicators for measuring defence status 5 . To this end, many cellular and humoral factors of shrimp and a few factors in prawns have been studied with the hope that they may be developed as indicators or as measures for the effectiveness of potential 'immunostimulants' 5 - 8 . In this study, phenoloxidase (PO) enzyme activity, agglutinin, lysozyme and protein levels have been examined to determine whether these could be used as indicators for the stimulatory activity for one of the commercial polyherbal immunopotentiators, viz., ImmuPius. Few of the immunostimulants viz., 3 glucan 5 · 6 , peptidoglycan 7 , lipopolysaccharide (LPS) and commercial stimulants, PENSTlM, BRM-01 and BRM-02 5 have been successfully tried to modulate non-specific immunity in shrimps and to enhance resistance against various bacterial, viral and fungal infections. Similarly, benzalkonium chloride 8 , having immunostimulant property has been evaluated in freshwater prawn. Medicinal plants, used in various traditional systems, have immune potential against various diseases 9 . More than 13,000 plants have been studied during the last five years for various pharmacological properties in animals and human beings 9 · 10 . ImmuPlus (Aqualmmu), a polyherbal formulation (Indian Herbs Supply and Research Company Limited, Saharanpur , India) contains the extracts of selected Indian medicinal plants viz., Ocimum sanctum (Tulsi), Withania somnifera (Ashwagandha), Tinospora