Effect of probiotics on immune competence of giant freshwater prawnMacrobrachium rosenbergii

Abstract

This study evaluates the effect of probiotics, Zymetin, on the immune efficiency of Macrobrachium rosenbergii juvenile against pathogenic Vibrio spp. and Aeromonas spp. The experiment was conducted in glass aquaria with same level of feeding under different treatments, that is, negative control (Cn), positive control with Vibrio spp. (Cv) and Aeromonas spp. (Ca), prawn juveniles fed with probiotics (Zymetin) at 5 g/kg of feed but without pathogen (T1), probiotic fed prawn challenged with Vibrio spp. (T2) and Aeromonas spp. (T3). The results demonstrated that T1 showed higher survival rate, total haemocyte count, non-granular haemocyte count, phagocytic activity, and clearance efficiency compared to other treatment groups. In contrast, decreased number of small and large granular haemocyte was observed in T1.Despite that, THC was found to be significantly different (p < 0.05) among all the controls and lowest was in Cv, followed by Ca. Besides, phagocytic activity and clearance efficiency against Vibrio spp. and Aeromonas spp. decreased significantly in Cn, Ca, and Cv fed M. rosenbergii juvenile, while the values were found to be higher in T1 followed by T2 and T3, in that order. In addition, the challenge test showed an increasing trend of total and beneficial bacterial density as well as declining trend of some harmful bacteria in the water and gut of prawn in all the groups tested (p < 0.05). K E Y W O R D Sclearance efficiency, Macrobrachium rosenbergii, phagocytic activity, probiotics wileyonlinelibrary.com/journal/are Aquaculture Research. 2019;50:644-657. 2 | MATERIALS AND METHODS 2.1 | Pathogen isolation, culture, and biochemical confirmation Before conducting the challenge test, the pathogenic bacteria (i.e., Vibrio spp. and Aeromonas spp.) were isolated from four diseased prawns which displayed typical symptoms of inactivity, poor growth leading to weight loss, anorexia, and frequent mortality. All the diseased GFP were collected from the farmer's pond of Dumuria, Khulna, Bangladesh. Infected prawns were brought to the Fish Pathology Laboratory of Fisheries and Marine Resource Technology AZAD ET AL.| 645

Application of probiotics and prebiotics for promoting growth of Tiger shrimp (Penaeus monodon): an approach to eco-friendly shrimp aquaculture

“…In the present study, total ammonia nitrogen was 2.22±0.19 and 0.32±0.06 in control and prebiotics probiotics treated ponds, respectively. Thus, maintaining the ammonia level probiotic and prebiotics help in maintaining good water quality and thereby keeps the shrimp disease free (Hossain et al, 2013;Azad et al, 2019). Most often economic analysis is an important issue for this kind of study.…”

“…M. rosenbergii is mostly (over 95%) produced by small-scale farmers, who harvest only a few kg of large shrimp per day. Shrimp exports total over 40,000 tonnes of P. monodon, M. rosenbergii and some smaller volumes of other species in 2016 and 2017 (Azad et al, 2019). Over 80% was exported to the EU market in 2017, especially to the Netherlands, Germany and Belgium.…”

“…Shrimp and prawn together represent the second largest exportable items contributing to foreign exchange earnings of Bangladesh (Ghosh et al, 2016;Azad et al, 2019). Shrimp farming has significant impact on environment and economy.…”

“…Although the country has a great history of shrimp/prawn farming, the productivity of shrimp is very low compare to the other shrimp producing countries of the world (Rahman and Rashid, 2013). One of the major causes of poor productivity is the extensive or traditional method of farming (90 percent of total farms), whereas developed countries brought their farms under intensive or semi-intensive methods of farming (Azad et al, 2019). Bangladesh has great potentiality to increase productivity of shrimp and prawn by introducing intensive and semiintensive methods of farming (Rahman and Rashid, 2013).…”

“…Probiotic are heterotrophic beneficial bacteria that remove deleterious nitrogenous compound from the aquatic system (Fernandes and Kerkar, 2019). The principal mode of action of probiotic bacteria is through competitive exclusion mechanisms in which pathogens are replaced or excluded through the development of a beneficial microbial population on the intestinal surface which leads to a reduction in disease, better health and thus better growth of the host (Jha, 2014;Azad et al, 2019). Thus, probiotics act as the alternatives of antibiotics and chemicals reducing diseases through maintaining pollution free environment (Kumar et al, 2016;Fernandes and Kerkar, 2019).…”