Growth and metabolic responses of juvenileMacrobrachium nipponenseto different dietary carbohydrate levels

Abstract

It remains controversial whether carbohydrate can be efficiently used by crustaceans.Six isonitrogenous and isolipid diets were formulated containing 50-350 g kg -1 corn starch and were fed to juvenile prawns (mean weight, 0.133 ± 0.003 g) for 56 days in five replicates. Prawns fed 50-150 g kg -1 corn starch attained significantly greater weight gain. Digestive enzyme activities were significantly affected by dietary corn starch level. Hepatopancreatic and muscle glycogen levels peaked in prawns fed 350 g kg -1 and 150 g kg -1 corn starch content, respectively. Prawns fed 350 g kg -1 corn starch had a significantly higher haemolymph glucose level than that in the other groups.Hepatopancreatic hexokinase (HK) activity increased significantly as corn starch level was increased. Hepatopancreatic pyruvate kinase (PK) activity of prawns fed the 150 g kg -1 and 250 g kg -1 corn starch was significantly higher than that of prawns fed 50 g kg -1 corn starch. Including carbohydrate in the diet promoted increased lipogenic activities (glucose-6-phosphate dehydrogenase and malic enzyme) in the hepatopancreas.Hepatopancreatic HK and PK mRNA expression levels had similar trends with their activities. The 350 g kg -1 corn starch level induced the highest glucose-6-phosphatase and pyruvate carboxylase mRNA expression levels. Overall, moderate metabolic adaptations for using dietary corn starch were detected in Macrobrachium nipponense; however, a high proportion (>150 g kg -1 ) of corn starch in the diet may reduce growth. K E Y W O R D Sdigestive enzymes activity, glucose metabolism, growth performance, Macrobrachium nipponense

Macronutrient modulation of mRNA and microRNA function in animals: A review

“…An appropriate level of carbohydrate may boost the antioxidative capacity and immune response in carp fish which may subsequently enhance the pathogen resistance and finally increase the growth. Similar results were observed in juvenile shrimps ( Ding et al., 2017 ) where the authors emphasize that the lower level of dietary carbohydrates resulted in a reduction of growth performance.…”

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Carbohydrates digestion and metabolism in the spiny lobster (Panulirus argus): biochemical indication for limited carbohydrate utilization

“…Similar results were found in the spiny lobster J. edwwarsii ; in this other lobster species, lower values of α-amylase activity in the foregut and digestive gland were observed in individuals ingesting a formulated diet containing 36% wheat starch compared to those ingesting fresh food ( Simon, 2009c ). Differences in α-amylase activity induced by diets with different CHs inclusion have also been found in other crustaceans ( Ding et al, 2017 ). Taken together with previous results and those obtained in this work, it is demonstrated that spiny lobsters are relatively insensitive to CHs source in terms of α-amylase secretion to the gastric juice, but that they modify the amount of α-amylase secreted according to the amount of starch in the usual diet.…”

Prospection of putative genes for digestive enzymes based on functional genome of the hepatopancreas of Amazon river prawn

“…Santos et al (2014) identified proteases in the hepatopancreas (trypsin, leucine aminopeptidase and chymotrypsin) of adult males of this species by using specific substrates and inhibition tests. These are considered indirect methods to evaluate enzyme activity as previously reported in other congeneric species: M. tenellun (Montoya Martinez et al, 2018), M. rosenbergii (Wattanakul, Wattanakul, Thongprajukaew, & Muenpo, 2015) and M. nipponense (Ding et al, 2016).…”