Effect of Optimum and Suboptimum Dietary Protein on Hemolymph Physiology, Oxidative Physiology, Plasma Fatty Acids, and Histoarchitectural Modulations in Farmed Giant Freshwater Prawns Macrobrachium rosenbergii

Abstract

We examined the effect of optimum (32%) and suboptimum (27%) levels of dietary protein on the hemolymph and oxidative physiology of giant freshwater prawn Macrobrachium rosenbergii juveniles. Wild juveniles of different stocks were collected from the west coast (Gujarat [G-stock] and Maharashtra [M-stock]) and east coast (Andhra Pradesh [A-stock]) of India. Prawns were raised in 200-m 2 culture ponds, with individual animals tracked by using stock-specific, colored elastomer tags. Hemolymph glucose, plasma total protein, albumin-to-globulin (A:G) ratio, plasma calcium, and activity of five key metabolic enzymes in plasma (plasma cholinesterase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, and amylase) were examined to compare the hemolymph physiology due to dietary protein variations fed to the different stocks. Plasma fatty acid profile was also monitored. Effect of feeding on oxidative physiology of prawns was analyzed by measuring the catalase and acetylcholinesterase activity in peripheral and brain tissues, respectively. Oxygen-dependent intrinsic defense ability was also measured by nitro blue tetrazolium-based respiratory burst activity. Physiology of prawns was correlated with the histological examinations of hepatopancreas and gills. Our results suggest that the hemolymph and oxidative physiology of giant freshwater prawns remained unaffected by the optimum and suboptimum dietary protein levels fed. Furthermore, stock-based differences in the response were evident: the G-stock and M-stock prawns exhibited healthier plasma and oxidative physiology than A-stock prawns. Our study provides a useful tool to select "good responder" stocks (genotypes) to obtain higher production levels in a given culture management scheme.During the last two decades, significant declines in commercial and/or wild stocks attributed to various factors, such as inbreeding, overharvesting, habitat loss, and increased pollution, have been observed across the entire natural range of the giant freshwater prawn Macrobrachium rosenbergii (i.e., Thailand, Bangladesh, India, Indonesia, Malaysia, and Philippines). This has drawn attention to the vulnerability of wild supplies and the need to develop domesticated stocks that

Effect of different stock types and dietary protein levels on key enzyme activities of glycolysis‐gluconeogenesis, the pentose phosphate pathway and amino acid metabolism inMacrobrachiumrosenbergii

“…Borinson et al () showed a decrease in gills LDH activity in Leiostomus xanthurus in response to hypoxia. Consequently, lower gill LDH activity in stock “A” can be correlated with the gills pathological conditions (massive edema with atrophy and hemocyte infiltration) found in this stock (Sagar et al, ). Similarly, lower LDH gills recorded for M. rosenbergii fed SDP may be due to the stress of energy deficiency and, in turn, lower survival of this stock (Sagar et al, ).…”

“…Therefore, although not significant, higher muscle LDH activity in optimum dietary protein fed M. rosenbergii can be correlated with their higher growth and survival than stock “A”’s growth and survival during the experimental period. We have demonstrated previously that optimum dietary protein (32%) fed M. rosenbergii achieves weight gain and higher specific growth rates of 95% and 80%, respectively in comparison to sub‐optimum dietary protein (27%) fed prawns (Sagar et al, ). In contrast, Manush et al () reported a gradual decrease in the hepatopancreatic LDH activity with increasing dietary protein level when prawns were stressed due to claw ablation.…”

“…Lupianez, Sanchez‐Lozano, Garcia‐Rejon, & De laHiguera () reported an increase in the activity of hepatic gluconeogenic enzymes when rainbow trout was fed a high dietary protein feed. The highest hepatopancreatic G6Pase activity recorded in stock "G" can be correlated with the overall higher growth rate of that stock (Sagar et al, ) i.e. more utilization of nutrients resulted in more metabolic activity.…”

“…However, commercial and/or wild stock of M. rosenbergii has been sharply declining all around the globe during the last two decades. Therefore priorities must be directed toward an approach to identify optimum stocks in a given culture condition (Bowyer et al, ; Davies, Gouveia, Laporte, Woodgate, & El‐Haroun, ; El‐Husseiny, Hassan, El‐Haroun, & Suloma, ; Goda et al, , ; Hassan et al, ; Hassaan, Mahmoud, et al, ; Hassaan, Soltan, et al, ; Kumar et al, ; Sagar et al, ). The growth performance of prawns is influenced by various factors such as water, soil quality, stocking density, sex ratio, feeding methods, and feed types.…”

“…Environmental factors, including feed, influences the production of hormones from key organs, and influences growth, maturation, and other important events in development. Previously, we quantitatively analyzed the different digestive enzymes in M. rosenbergii in response to various feed nutrient compositions, including dietary protein level (Sagar et al, ). The current study was the first step toward delineating the effect of dietary protein on key enzymes of glycolysis, gluconeogenesis, amino acid catabolism, pentose phosphate pathway, and energy metabolism in different stocks of M. rosenbergii .…”