This study assessed the activity of the main digestive enzymes in juveniles of the painted river prawn Macrobrachium carcinus. Prawns reared in 24 m² tanks at a density of 10 individuals. m⁻² for 45 days were fed a commercial diet with 40 % crude protein. A sample of 21 prawns with 2.92 ± 0.60 g and 27.87 ± 1.50 mm had their midgut glands (MG) dissected. Assays prospecting total proteolytic activity, total amylase, α-amylase, trypsin, chymotrypsin, β-galactosidase, agarase and lipase in the MG were performed. The activities of several aminopeptidase (alanine, arginine, glycine, histidine, isoleucine, leucine, proline and tyrosine aminopeptidase) were also evaluated. In addition, the effect of calcium (CaCl₂) on trypsin activity was assessed. The following mean (± SD) activities were found: total proteolytic activity (8.00 ± 0.003 U.mg^-1); total amylase (0.322 ± 0.002 U.mg^-1); α-amylase (8.730 ± 0.008 U.mg^-1); trypsin (12.7 ± 0.001 mU.mg^-1); chymotrypsin (19.94 ± 0.0019 mU.mg^-1); β-galactosidase (59.4 ± 0.18 U.mg^-1); agarase (13.34 ± 0.15 U.mg^-1) and lipase (0.019 ± 2.73 U.mg^-1). Amongst aminopeptidases, only alanine, arginine, glycine and leucine aminopeptidase were found to be active. At concentrations from 5 to 90 mM, the activity of trypsin was not affected by CaCl₂. Compared to other prawn species, M. carcinus has a wide range of digestive enzymes and a tendency towards greater use of animal protein. As studies on the digestive enzymes of juvenile prawns of the Macrobrachium genus are scarce, the present results represent basic data that may serve as a reference for future studies and also aid in the formulation of diets specific for this important group of crustaceans.

本研究评估了彩绘河虾沼虾幼鱼的主要消化酶活性。大虾在24 m ^2的水箱中饲养，密度为10个人。在m ^-2下持续45天，向其饲喂40％粗蛋白的商业饲料。解剖了21个虾，其虾的中肠腺（MG）为2.92±0.60 g和27.87±1.50 mm。对MG中的总蛋白水解活性，总淀粉酶，α-淀粉酶，胰蛋白酶，胰凝乳蛋白酶，β-半乳糖苷酶，琼脂酶和脂肪酶进行了测定。还评估了几种氨基肽酶（丙氨酸，精氨酸，甘氨酸，组氨酸，异亮氨酸，亮氨酸，脯氨酸和酪氨酸氨基肽酶）的活性。此外，钙（CaCl ₂）评估胰蛋白酶活性。发现以下平均（±SD）活性：总蛋白水解活性（8.00±0.003U.mg ^-1）；总蛋白水解活性（8.00±0.003U.mg ^-1）。总淀粉酶（0.322±0.002 U.mg ^-1）; α-淀粉酶（8.730±0.008 U.mg ^-1）; 胰蛋白酶（12.7±0.001 mU.mg ^-1）; 胰凝乳蛋白酶（19.94±0.0019 mU.mg ^-1）; β-半乳糖苷酶（59.4±0.18 U.mg ^-1）; 琼脂酶（13.34±0.15 U.mg ^-1）和脂肪酶（0.019±2.73 U.mg ^-1）。在氨基肽酶中，仅丙氨酸，精氨酸，甘氨酸和亮氨酸氨基肽酶是有活性的。在5至90 mM的浓度下，胰蛋白酶的活性不受CaCl _2的影响。与其他虾种相比癌分支杆菌具有广泛的消化酶，并且倾向于更多地使用动物蛋白。由于对沼虾属幼虾消化酶的研究很少，因此本研究结果代表了基础数据，可为将来的研究提供参考，并有助于制定针对这一重要甲壳类动物的饮食。