Ovarian development and nutritional quality changes of the wild‐caught Portunus trituberculatus during the artificial fattening period

A female swimming crab (Portunus trituberculatus) with fully developed ovaries is considered one of the most nutritious types of seafood. The fishing yield of P. trituberculatus in China has always been high; however, its economic value has been low and unreliable due to poor ovarian development and low nutritional value. Artificial fattening is an effective way to improve the value of wild‐caught crabs, and this study focused on analysing the ovarian development and nutritional quality of the female P. trituberculatus during an artificial fattening period. Therefore, this study provides scientific evidence on the effects of artificial fattening on female P. trituberculatus and can guide the development of nutritional quality regulations for wild‐caught female crabs during the fattening process. The results showed that the ovaries of the wild female P. trituberculatus developed gradually. The ovarian morphology became bulkier, while the gonadosomatic index (GSI) and total edible yield (TEY) were significantly improved after artificial fattening. Significant changes in the nutritional components of the edible tissues were observed, and the moisture content in the ovaries and hepatopancreas decreased continually, while both the protein and fat content in the ovaries significantly increased. Moreover, the fat content in the hepatopancreas significantly increased. The saturated fatty acids(ΣSFA) in the ovaries and hepatopancreas had an increasing trend after fattening, while ΣPUFA and Σn‐3PUFA first decreased and then increased. In contrast, the ratio of Σn‐3PUFA to Σn‐6PUFA decreased steadily. However, the fatty acid composition of the muscles did not change significantly. The levels of all the amino acids increased continuously during the fattening process, and EAA increased significantly in the early stages of the fattening period. Consequently, all amino acids became nonlimiting amino acids after fattening. Furthermore, the ratio of EAA/NEAA in the ovaries increased continually until the end of the fattening period. On the other hand, the fatness and TEY increased significantly after artificial fattening. In addition, the nutritional value significantly improved with the exception of the high‐quality fatty acids in the ovaries and hepatopancreas, which were slightly lower in both.     

Biochemical composition of pond-reared and lake-stocked Chinese mitten crab Eriocheir sinensis (H. Milne-Edwards) broodstock

The morphological characteristics, tissue indices, proximate and fatty acid compositions of hepatopancreas, gonad and muscle of pond‐reared (PR) and lake‐stocked (LS) Eriocheir sinensis broodstock were compared. Lake‐stocked crabs are characterized by a blue carapace, white abdomen, golden legs and yellow setae while PR crabs have a brown carapace, grey abdomen, black legs and similar yellow setae. The carapace length and width of PR crabs were significantly less than those of LS crabs of the same wet weight (WW). The results showed that the hepatosomatic index (HSI) of PR males was significantly higher, but the gonadosomatic index (GSI) was significantly lower for PR females when compared with LS individuals of the same sex. Regardless of their origin, the muscular index (MI) of males was higher than that of females. The hepatopancreas of LS crabs had higher protein levels and lower lipid levels compared with PR crabs. The results of proximate analysis of male gonads from two different sources were similar, while the protein level in the ovary of LS females was higher than that of PR females. The tissues of males had higher water content but lower lipid and protein levels compared with females regardless of their source. The LS crabs had higher highly unsaturated fatty acid (HUFA) levels than PR crabs in their gonad and hepatopancreas. In conclusion, our results suggest that the nutritional quality of LS crabs is better than that of PR crabs, the nutritional quality of males is poorer than that of females. The reproductive performance and larval quality of crabs from these two rearing systems should be further verified.     

Study on the nutritional quality of ecologically bred Chinese mitten crabs with different body weights

To provide basic nutritional data and theoretical support for the processing and comprehensive utilization of the Chinese mitten crab, we performed a systematic study of the nutritional components of three edible parts, namely the hepatopancreas, gonads and abdominal muscle, of three groups of animals differing in body mass: 75.55 ± 1.56 g, 100.24 ± 2.04 g and 162.27 ± 3.44 g. The results showed that with a greater body mass, the water content was higher, the protein and ash contents were first higher and then lower, and the fat content was first lower and then higher. Amino acids (AAs), essential AAs (EAAs) and the EAA/AA ratio were first higher and then lower, all reaching the standard for high‐quality protein. The most limiting AA was valine. The EAA index was greater than 97 for all three edible parts of the medium‐sized crabs, indicating that crabs in this size group had very high nutritional value. The numbers of detected fatty acids were the same among the edible parts and the three size groups of the river crabs. Among the mineral elements measured, Ca, K and Na were the most abundant and showed a trend of first being higher and then being lower with a larger crab size. Although heavy metals were detected, the Cr, Pb and Cd levels were all within the permissible limits. Therefore, the nutritional quality of the three edible parts was greater for medium‐sized river crabs than for small and large mitten crabs.     

Nutritional qualities of normal and precocious adult male Chinese mitten crabs (Eriocheir sinensis)

The nutritional values of edible gonad, hepatopancreas and muscle tissues from normal and precocious adult male Chinese mitten crabs (Eriocheir sinensis) were investigated herein. The results showed that the average weight and meat yield (MY) of normal crabs were significantly higher than those of precocious crabs, while the hepatopancreas indexes (HSI) and gonadosomatic indexes (GSI) had no significant differences. Precocious and normal crabs had greater protein and lipid contents, respectively, and the differences were mainly reflected in gonads and hepatopancreas. While assessing the amino acid profiles, both precocious and normal crabs could be high‐quality protein sources, particularly the precocious crabs which showed higher levels of essential amino acids. In fatty acid profiling experiments, precocious crabs revealed higher EPA, ∑n‐3 polyunsaturated fatty acids (PUFA) and ∑n‐3/∑n‐6 ratios than normal crabs; however, DHA and ∑n‐6 PUFA contents were considerably lower. Additionally, contents of nutritious minerals K and Ca in precocious crabs were significantly higher than those in normal crabs, while Zn and Fe were significantly lower. In short, our data indicated that precocious Chinese mitten crabs are also a nutritious food, and even in some respects their nutritional value is higher than normal crabs.     

伊乐藻对中华绒螯蟹生长和营养品质的影响

本研究分析了有伊乐藻(Elodea nuttallii)组和对照组(无伊乐藻)中华绒螯蟹(Eriocheir sinensis)在生长、肌肉氨基酸和脂肪酸组成等方面的差异,探讨伊乐藻对中华绒螯蟹生长和营养品质的影响。结果显示,有伊乐藻组中华绒螯蟹体重、壳长和壳宽增长率与肥满度均显著高于无伊乐藻组(P0.05),但肝胰腺指数和性腺指数差异不显著(P0.05)。伊乐藻组中华绒螯蟹肌肉的氨基酸总量、必需氨基酸和鲜味氨基酸含量均显著高于无伊乐藻组(P0.05);伊乐藻组的雌蟹肝胰腺中的鲜味氨基酸含量也显著高于无伊乐藻组(P0.05),而伊乐藻组和无伊乐藻组的雄蟹肝胰腺氨基酸含量差异不显著(P0.05)。伊乐藻组和无伊乐藻组的中华绒螯蟹肌肉脂肪酸组成和含量差异不显著(P0.05),但伊乐藻组中华绒螯蟹的肝胰腺饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)和多不饱和脂肪酸(PUFA)含量均显著高于无伊乐藻组(P0.05)。综上所述,伊乐藻不仅有利于中华绒螯蟹的生长,而且能改善中华绒螯蟹的营养品质。     

“Butter Crab”: an environment‐induced phenotypic variation of Scylla paramamosain with special nutrition and flavour

An “abnormal” female Scylla paramamosain, named “Butter crab” (B_♀) is more popular than wild‐type mud crab (CK) with people. Histologically, “butter crab” ovaries are partially degraded, with full of yellow oily substances in body. Composition of the essential nutritional components is quite similar in “butter crab” and CK. In a comparison of fatty acids, B_♀ is richer. A comparison of flavour amino acids and nucleotide in muscle showed that sweet amino acids and bitter amino acids in B_♀ is lower than CK_♀, but umami amino acids are significantly higher in B_♀. However, the umami amino acid content in the gonads is significantly less in B_♀ than CK_♀. Moreover, umami nucleotides in B_♀ muscle is significantly higher. From the perspective of EUC evaluation, the umami taste of CK_ ♀ gonads is strongest, followed by B_ ♀ gonads. In the hepatopancreas, the umami taste ranks CK_♀> B_♀ >CK_♂, and there are no significant differences among muscles in the three groups. In conclusion, the characteristics of “butter crab” are more fragrant and nutritious, with sweet and umami taste. The article systematically scientifically analysed the nutritional composition and flavour characteristics of “butter crab”, providing a novel insight for development of S. paramamosain industry.     

不同生态环境中华绒螯蟹肉脂品质的比较

选取长江野生、湖泊放流、网围养殖及池塘养殖的中华绒螯蟹成蟹各10只,雌、雄各半,对其进行62个肉脂品质参数的测算。可食部分占体重的29.79%~38.60%,可食部分蛋白含量和粗脂肪含量分别为15.45%~20.32%和8.52%~17.33%,含水量为56.70%~70.30%;必需氨基酸和鲜味氨基酸分别占可食部分的5.29%~7.22%和6.40%~7.91%,氨基酸总量占13.48%~17.57%;可食部分饱和脂肪酸含量约为0.80%~1.71%;不饱和脂肪酸含量约为3.61%~9.29%;高不饱和脂肪酸含量约为0.65%~2.79%;脂肪酸总含量约为4.41%~10.96%。组内雌、雄可食部分比例、粗脂肪、灰分、脂肪酸、微量元素等参数差异较小;水分、粗蛋白、氨基酸等参数差异较大,粗蛋白、氨基酸各有显著差异的参数值均为雄蟹小于雌蟹。同性别不同生态环境成蟹粗蛋白、氨基酸各参数的差异较小;可食部分比例、粗脂肪、水分、灰分、脂肪酸、矿质元素等参数差异较大。综合均值比较结果和实践经验分别选取13个和16个参数,对4组雄蟹、4组雌蟹进行判别,结果表明所选取参数可较好反映中华绒螯蟹肉脂品质的差异。用62个参数分别对4组雄蟹、4组雌蟹进行聚类分析,从总体上反映了不同生态环境中华绒螯蟹的肉脂品质和其相互关系。     

Effect of dietary lipids and vitamin E on growth performance,body composition,anti‐oxidative ability and resistance to Aeromonas hydrophila challenge of juvenile Chinese mitten crab Eriocheir sinensis

Vitamin E supplement is important in protecting lipid oxidation and enhancing immunity of aquatic animals. A 10‐week feeding trial was conducted to evaluate the effect of dietary lipid and vitamin E on juvenile Chinese mitten crab Eriocheir sinensis. The experimental diets included three levels of vitamin E (0, 100 and 300 mg kg^?1) and two levels of lipid (6% and 9%). The 9% lipid diet significantly enhanced the body lipid of crabs compared with the 6% lipid diet. The vitamin E concentration of hepatopancreas increased with the increase in vitamin E in the diets regardless of dietary lipid levels. The hepatopancreas fatty acids, especially polyunsaturated fatty acid and highly unsaturated fatty acid, were significantly enhanced by vitamin E supplement or 9% dietary lipid. Vitamin E supplement significantly increased the total antioxidant capacity, superoxide dismutase, lysozyme and phenoloxidase activities of crabs compared with those fed the diets without vitamin E supplement. The hepatopancreas malondialdehyde of crabs fed 100 mg vitamin E kg^?1 was significantly lower than those fed 0 or 300 mg vitamin E kg^?1. The phenoloxidase activity of crabs fed the 9% lipid diet was significantly higher than those fed 6% lipid, irrespective of vitamin E levels. Vitamin E supplementation increased the bacterial resistance of juvenile crab. This study indicates that dietary lipid and vitamin E supplement do not affect crab growth and survival, but vitatmin E supplement at 100 mg kg^?1 can enhance immunity and antioxidant capacity of crab fed 6% or 9% dietary lipids.     

育肥时间对三疣梭子蟹卵巢发育和营养品质的影响

采用育肥养殖实验和生化分析技术,研究了育肥时间对三疣梭子蟹雌体卵巢发育和营养品质的影响。结果发现,(1)经90 d育肥的雌体卵巢指数显著上升,出肉率和总可食率呈先上升后下降趋势,育肥30~60 d的总可食率达42%以上。(2)育肥时间对肌肉中常规营养成分含量无显著影响,育肥60 d卵巢和肝胰腺中的蛋白质、脂肪和碳水化合物含量最高,水分含量最低;育肥使肝胰腺和卵巢中胆固醇百分含量呈显著下降趋势,育肥后期卵巢和肝胰腺中的磷脂含量显著上升;就不同组织而言,肝胰腺中的甘油三酯含量最高。(3)育肥使卵巢和肝胰腺中的单不饱和脂肪酸呈上升趋势,而多不饱和脂肪酸呈先下降后上升趋势,肌肉中脂肪酸组成无显著变化;整体上,肌肉的脂肪酸营养价值优于肝胰腺和卵巢。(4)育肥早期卵巢中氨基酸含量显著上升,整个育肥过程中肌肉中的甜味氨基酸含量呈显著上升趋势,育肥60 d后卵巢和肌肉中所有必需氨基酸分值均大于100,无限制性氨基酸。研究表明,生殖蜕壳后的三疣梭子蟹雌体适宜育肥时间为60 d,育肥不仅提高了总可食率,且优化了其营养价值。     

Effect of dietary lipid source and vitamin E on growth,non‐specific immune response and resistance to Aeromonas hydrophila challenge of Chinese mitten crab Eriocheir sinensis

Six purified diets were formulated to contain three lipid sources, fish oil (FO), linseed oil (LO) and soybean oil (SO), at 6% diet lipid crossing two levels of vitamin E (100 and 300 mg α‐tocopheryl acetate/kg diet) for each lipid source (FO100, FO300, LO100, LO300, SO100, SO300). The juvenile Chinese mitten crab, Eriocheir sinensis, respectively, fed on these diets with four replicates for 6 weeks. The crab weight gain (WG) and specific growth rate (SGR) were significantly affected by dietary lipid sources. No difference was found between the crabs fed two levels of vitamin E, but the WG and SGR were numerically higher in crab fed 300 mg/kg vitamin E than those fed the other level of vitamin E. The lipid source and vitamin E level could affect fatty acid composition in the hepatopancreas. The contents of saturated fatty acids (SAFA) and n‐3HUFA were significantly higher in the crab‐fed fish oil. The highest contents of n‐6PUFA and n‐3PUFA were found in the crab‐fed soybean oil and linseed oil respectively. The contents of SAFA, n‐3HUFA and n‐3PUFA were higher in the 300 mg/kg vitamin E treatment. A lower malondialdehyde (MDA) content and higher phenoloxidase (PO) activity were observed in the crab fed 300 mg/kg vitamin E. The results of this study indicate that the Chinese mitten crab fed the diet with 6% fish oil and 300 mg/kg vitamin E showed better growth, antioxidant capacity and resistance to Aeromonas hydrophila.     

Effects of dietary fish oil replacement with blended vegetable oils on growth,lipid metabolism and antioxidant capacity of subadult swimming crab Portunus trituberculatus

A 120‐day trial was conducted to assess the effects of dietary fish oil replacement with vegetable oils on growth, lipid metabolism and antioxidant capacity of subadult swimming crab Portunus trituberculatus. Five isonitrogenous and isolipidic diets were formulated to replace 0, 250, 500, 750 and 1000g/kg of fish oil with a mixture of soybean and rapeseed oil (defined as D1–D5), and each treatment had 30 replicate crabs. Dietary fish oil replacement had no significant effects on growth of the crabs, while the D3 had the highest hepatosomatic index and total lipids in hepatopancreas. The triglyceride and lipase activities in hepatopancreas increased significantly with increasing dietary fish oil replacement. The D4 had the highest levels of alkaline phosphatase (ALP) and acid phosphatase (ACP) in the hepatopancreas, as well as the haemolymph ALP, ACP and peroxidase. The highest levels of haemolymph total antioxidant capacity, catalase and malondialdehyde were detected in D1. Total n‐3 polyunsaturated fatty acids levels in hepatopancreas decreased significantly with increasing dietary fish oil replacement. In conclusion, dietary fish oil replacement had no significant effects on growth of P. trituberculatus, and 500g/kg of fish oil replacement could improve antioxidant capacity, but excessive replacement level will enhance lipid accumulation and peroxidation in the hepatopancreas.     

Effects of different dietary lipid sources on tissue fatty acid composition,serum biochemical parameters and fatty acid synthase of juvenile mud crab Scylla paramamosain (Estampador 1949)

A 6‐week study was conducted to determine the effects of different lipid sources in pelleted diets on juvenile mud crab Scylla paramamosain. Five isonitrogenous and isolipidic diets containing 8% level of fish oil (FO), lard (LD), safflower oil (SO), perilla seed oil (PO) or mixture oil (MO; V_FO:V_SO:V_PO = 1:1:1), and a live food of marine bivalve Potamocorbula rubromuscula as the control diet (CF), were fed to groups of 25 juvenile crabs (average initial weight 7.4 g, carapace width 3.5 cm) in triplicate. The results showed that crabs fed MO had the highest survival (P < 0.05). The moisture content was significantly higher in crabs fed LD, SO and PO (P < 0.05). Crabs fed SO exhibited the lowest crude protein and lipid (P < 0.05). Ash contents were obviously lower in LD group (P < 0.05). Highest total lipid in the hepatopancreas and muscle was in LD and FO group respectively. Glucose, total cholesterol and low‐density lipoprotein were higher while high‐density lipoprotein was lower (P < 0.05) in LD group. Tissue fatty acid compositions were consistent with those in diets. FO and MO diets had the same depression effect like CF on fatty acid synthase activity and mRNA expression in the hepatopancreas. The results of this study indicated that FO and mixed oil are suitable for preparation of pelleted diets with better effects for juvenile S. paramamosain compared with live food, and the ratio of n‐6/n‐3 fatty acids in pelleted diets must be <1.     

不同养殖水域中华绒螯蟹滋味差异分析

本研究分析不同水域中华绒螯蟹(Eriocheirsinensis)可食率和滋味差异,以期为挖掘消费者不同偏好性的内在原因提供参考.选取阳澄湖、固城湖、太湖和兴化大闸蟹为研究对象,测定可食率、整体滋味轮廓、滋味相关指标.结果显示,太湖蟹可食率最高,雄蟹为(33.08±0.31)％,雌蟹为(37.65±1.09)％;在整体...     

池塘养殖条件下长江、黄河和辽河种群中华绒螯蟹雌体卵巢发育和营养组成的比较研究

为研究长江、黄河和辽河中华绒螯蟹养殖种群在相同养殖条件下的成蟹性腺发育和营养组成,采用养殖实验和生化分析方法,比较了池塘养殖条件下3种群雌体的性腺发育情况,在此基础上比较了雌体的可食率、肥满度和可食组织中的营养组成,结果显示:(1)3种群雌体性腺发育速度存在显著差异,性腺发育顺序为辽河种群黄河种群长江种群,但10月底辽河和黄河种群的卵巢指数无显著差异。(2)在体质量和卵巢指数接近的条件下,3种群雌体膏蟹的肝胰腺指数、出肉率、总可食率和肥满度均无显著差异。(3)3种雌体卵巢、肝胰腺和肌肉中的常规生化成分含量接近,仅长江种群雌体肌肉和肝胰腺中的灰分含量显著高于其他3种群,其他指标均无显著差异。(4)3种群卵巢中脂肪酸组成接近,但长江种群卵巢中C22∶6n3(DHA)百分含量显著高于黄河种群;3种群雌体肝胰腺和肌肉中的脂肪酸组成相近,仅肝胰腺中的C20∶1n9和C20∶4n6含量存在显著差异。(5)长江种群雌体卵巢中的苯丙氨酸、酪氨酸、色氨酸、天冬氨酸和丝氨酸含量均显著高于辽河种群;黄河种群雌体肌肉中大部分必需氨基酸(EAA)和非必需氨基酸(NEAA)含量均为最高,故其总氨基酸(TAA)含量也显著高于其他两个种群。(6)3种群雌体卵巢和肌肉中均无限制性氨基酸,长江种群雌体卵巢和黄河种群雌体肌肉中的平均必需氨基酸分(EAAS)分别最高;整体上,雌体卵巢中的平均EAAS高于肌肉组织。研究表明,长江种群雌体卵巢发育速度最慢,辽河种群相对较快,3种群雌体可食组织中的常规营养成分和脂肪酸含量接近,肌肉中的氨基酸含量存在较大差异,但其卵巢和肌肉中均无限制性氨基酸。     

中华绒螯蟹肝胰腺白化症的病因研究

2002年10月以来,通过逐户访问及调查问卷的形式对2001～2002年东太湖中华绒螯蟹(Eriocheir sinensis)养殖区"白膏症"发病症状、扣蟹的来源、投饵模式、水草覆盖率、螺蛳投入量、底泥状况、回捕率、产量等进行较为系统的调查。同时对病蟹进行寄生虫检查、病原微生物分离、回接攻毒及病变组织的电镜观察等病原学研究,结果未发现致病性生物。调查结果表明,中华绒螯蟹"白膏症"的发病率雄蟹显著高于雌蟹,其症状为甲壳发黄,头胸甲腹面下肝区发白色或青黑色,肝胰腺由正常的橘黄色变成淡黄或白色;症状严重的病蟹胸腔积水,肌肉松驰萎缩,肝胰腺呈糜烂状,鳃丝发黑。调查结果显示,"白膏症"的发生与饵料的投喂量、动植物饵料之比及水环境有着密切的联系。根据该病的主要症状及发病原因,认为该病应命名为中华绒螯蟹肝胰腺白化症。     

Cottonseed meal protein hydrolysate stimulates feed intake and appetite in Chinese mitten crab,Eriocheir sinensis

One hundred and twenty crabs (initial weight: 51.32 ± 0.06 g) were fed three experimental diets with cottonseed meal protein hydrolysate (CPH) at 0, 6 and 12 g/kg for 60 days. The results showed that CPH0.6 diet significantly improved the 1‐hr feed intake, protease activity and weight gain of crabs. In thoracic ganglia, 4E‐binding protein (4E‐BP) expression level of crab fed the diets containing CPH was significantly higher than CPH0 group. In cerebral ganglia, protein kinase B and 4E‐BP expression levels of crab fed CPH0.6 diets were significantly lower than CPH0 group. In mid‐intestine, target of rapamycin (TOR) relative expression level of crabs fed the diets containing CPH was significantly lower than CPH0 group. 4E‐BP expression level showed an opposite pattern. In thoracic ganglia, cerebral ganglia and mid‐intestine, leptin receptor expression level of crabs fed CPH0.6 diet was significantly lower than CPH0 group. Neuropeptide Y and neuropeptide Y receptor expression level of crab fed CPH0.6 diet was significantly higher than CPH0 group. In conclusion, our results indicated that dietary supplementation of 6 g/kg CPH could stimulate appetite and quicken feeding rate via the TOR signalling pathway.     

中华绒螯蟹不同可食部位对恩诺沙星的富集效应研究

为了探究广谱抗菌药恩诺沙星暴露对中华绒螯蟹(Eriocheir sinensis)各可食部位(蟹腿肉、蟹身肉、性腺和肝胰腺)的影响,实验设置了空白对照组和三个恩诺沙星浓度试验组(空白对照、50、500和5000μg/L)来进行研究.结果表明:恩诺沙星在各部位的富集系数与水环境中恩诺沙星的浓度呈负相关关系,在蟹身肉中的富...     

磷脂和HUFA对中华绒螯蟹幼蟹存活、生长、蜕壳及生化组成的影响

实验用中华绒螯蟹(Eriocheir sinensis)幼蟹初始体质量为1.8 g左右。饲料A添加6%鳕鱼肝油和4%大豆卵鳞脂(饲料含4.53%磷脂和1.08%HUFA), 饲料B添加10%的猪油(饲料含0.39%磷脂和0.18%HUFA); 实验蟹单个体饲养(可防止蜕壳期间蟹相互残杀而获得饲料外的营养源), 雌蟹(F)、雄蟹(M)各60个, 实验周期120 d。结果表明: 两组饲料条件下, 幼蟹的存活率、增重率、特定生长率、平均蜕壳次数、蜕壳间隔时间及肝胰腺指数均无显著差异(P>0.05)。但无论是雌蟹还是雄蟹, A组幼蟹肝胰腺和肌肉的总脂含量显著低于B组(P<0.05), 并且A组蟹肝胰腺和肌肉中磷脂、多不饱和脂肪酸和高度不饱和脂肪酸的含量显著高于B组(P<0.05)。这表明, 在中华绒螯蟹幼蟹饲料中添加4.53%磷脂和1.08%HUFA对其存活、生长、蜕壳无显著影响, 但可使其肝胰腺和肌肉中的总脂含量降低, 而磷脂、多不饱和脂肪酸和高度不饱和脂肪酸的含量升高。本研究结果旨在为中华绒螯蟹幼蟹的营养学研究提供理论依据, 同时也为生产上幼蟹饲料的开发提供参考。