In Vitro and In Vivo Feedstuff Digestibility for Snook,Centropomus undecimalis,Juveniles

The degree of hydrolysis (DH) of the ingredients was evaluated for Centropomus undecimalis juveniles. The in vitro experiment included wheat gluten (WG), corn gluten (CG), soybean meal (SBM) and pretreated phytase (SBM + phytase), soy protein concentrate (SPC), canola meal (CAN) and pretreated phytase (CAN + phytase), poultry byproduct meal (PBPM), chicken meal (CHKM), dried whey (DW), Pota meal (PM: mix of giant squid, fish soluble protein concentrate, crustacean meal, and fish oil), and Protiblend (PTB: aquatic and render mix). The highest acidic DH occurred with PTB (0.38 ± 0.06), CHKM (0.33 ± 0.3), and PBPM (0.25 ± 0.03). In the alkaline condition, PTB (1.6 ± 0.17 and 0.98 ± 0.05 for pyloric caeca and intestine, respectively) and CG (1.04 ± 0.4 and 0.75 ± 0.2 for caeca and intestine, respectively) provided the highest DH values. In vitro digestibility demonstrated that PTB was the highest (85.3%) followed by PBPM (51.4%), CAN + phytase (47.6%), CG (45.1%), and CHKM (46.5%). The in vivo experiment concerned the WG, CHKM, PBPM, PM, and PTB diets plus a reference diet with fishmeal (Ref diet). The total %DH was different (P < 0.05) with the lowest values for the WG diet (0.34 ± 0.09%) and Ref diet (0.34 ± 0.15). Free amino acid released during digestion was displayed for these diets and a bifactorial analysis produced no difference (P > 0.05). The apparent digestive coefficients ranged from 89.8 to 92.9% for protein and from 68 to 71.4% for energy.     

克氏原螯虾幼体发育时期消化酶活力及氨基酸含量研究

采用生物化学方法对克氏原螯虾各期幼体消化酶活力与氨基酸组成进行了分析。实验结果显示,在克氏原螯虾幼体发育过程中,五种消化酶活力(胃蛋白酶、类胰蛋白酶、淀粉酶、纤维素酶和脂肪酶)表现出两种变化模式:胃蛋白酶和类胰蛋白酶在幼体发育Ⅱ龄幼体期和Ⅳ龄幼体期活力较高,其中Ⅳ龄幼体期该两种酶活力最高;淀粉酶、纤维素酶和脂肪酶活力为先增高后降低,在Ⅲ龄幼体期,三种酶的活力达到最高,但与Ⅳ龄幼体期的酶活力比较无显著差异。总氨基酸含量在幼体发育早期逐渐降低,幼体发育至Ⅲ龄幼体期,其氨基酸含量最低,Ⅳ龄幼体期又有所增加。在测定的所有氨基酸中谷氨酸含量最高,必需氨基酸中赖氨酸含量最高,单个必需氨基酸含量与必需氨基酸总量的比值(A/E)在整个胚胎发育过程中的变化趋于一致。     

海洋仔鱼消化酶变化及饵料的影响

近年来海洋仔鱼消化系统,包括胃、肠道以及胰脏发育的研究进展进行了综述,描述了其消化系统在发育过程中形态和功能的变化,对仔鱼发育过程中包括胃蛋白酶、胰酶、肠酶及其他消化酶的变化以及饵料组分的影响进行了总结。     

盐度胁迫对高体革鯻幼鱼消化酶活力的影响

研究了盐度对高体革（Scortum barcoo）幼鱼消化酶活力的影响。在温度25±2℃下,将平均体质量为2.50±0.23 g的高体革幼鱼分别饲养在盐度0,5,8,11,13和16条件下20 d,检测幼鱼胃蛋白酶、淀粉酶和脂肪酶活性的差异。结果表明：盐度胁迫对高体革幼鱼胃蛋白酶活力有显著影响（P〈0.05）,对脂肪酶和淀粉酶活力有极显著影响（P〈0.01）。随着盐度的升高,胃蛋白酶活力先升后降,当盐度升高到13时又急剧升高;脂肪酶的活力则是随盐度的升高而受到抑制,当盐度升高到13时也急剧升高,盐度16时最高;而淀粉酶活力变化则是盐度升高时显著降低。这说明环境盐度对高体革消化酶比活力的影响比较大,不同消化酶随盐度变化规律有所差异。     

盐度胁迫对高体革鯻幼鱼消化酶活力的影响

研究了盐度对高体革（Scortum barcoo）幼鱼消化酶活力的影响。在温度25±2℃下,将平均体质量为2.50±0.23 g的高体革幼鱼分别饲养在盐度0,5,8,11,13和16条件下20 d,检测幼鱼胃蛋白酶、淀粉酶和脂肪酶活性的差异。结果表明：盐度胁迫对高体革幼鱼胃蛋白酶活力有显著影响（P〈0.05）,对脂肪酶...     

不同饵料对瓦氏黄颡鱼稚鱼生长和消化酶活性的影响

将瓦氏黄颡鱼(Pelteobagrus uachelli)稚鱼分为活饵料组(L)、驯化组(D)和饲料组(MP),分别对3个组进行牛长和消化酶活性的监测.结果表明,瓦氏黄颡鱼稚鱼在整个试验期间的特定牛长率,活饵料组>驯化组>饲料组,且3组之间均存在显著性差异(P<0.05).3个组蛋白酶的比活力均随日龄的增加而增加,活饵料组的蛋白酶比活力高于驯化组和饲料组(P<0.05).活饵料组的淀粉酶比活力在试验期间一直处于较低的水平,而驯化组和饲料组的淀粉酶比活力则呈现增加的趋势.活饵料组、驯化组和饲料组的脂肪酶比活力在45日龄以前基本维持在一个特定水平,饲料组的脂肪酶比活力高于驯化组和活饵料组(P<0.05),在45日龄以后,驯化组、饲料组的脂肪酶比活力呈增加的趋势,活饵料组的脂肪酶比活力则呈现降低的趋势.     

Activities of digestive enzymes and histology of digestive system during larval development of devil stinger (Inimicus japonicus)

Devil stinger is a valuable demersal scorpaenid fish while the rearing of stinger larvae still relies on live prey. This study was conducted to illustrate the development of the main digestive enzymes and digestive system during larval development of this species to provide evidence for the application of artificial feeds. Enzymatic and histological assays were conducted from 1 day post hatching (dph) to 36 dph in larvae. The result showed that the selected digestive enzyme activities increased significantly after 15 dph. Specifically, the total trypsin activities increased significantly from 18 dph to 33 dph. The total pepsin and amylase activities increased significantly first and thereafter decreased significantly. The lipase activities followed the similar pattern with trypsin. With regard to the histological study, the stinger larvae open their mouth to first feeding at 3 dph and turned into totally exogenous nutritional stage at 6 dph. In addition, mucous membrane, rich in goblet cells, was widely distributed in oesophagus epithelium at 18 dph. The height and amounts of gastric gland in cardia and main body of the stomach increased gradually with the development of stinger larvae after 15 dph. The intestine length of stinger larvae was short, and goblet cell was abundant in anterior intestine after 12 dph, not the posterior intestine. The ontogeny of liver and pancreas started from newly hatched stage, and the differentiation of liver was prior to pancreas. The above findings would provide evidence for the use of artificial feeds from the larval stage of stinger larvae (at least from 21 dph).     

银鲫消化酶活性与pH值的关系

实验结果表明：在肝胰脏、前肠、中肠、后肠，胰蛋白酶的最适pH值分别是7．5、7．5、8．5、8．0；脂肪酶的最适pH值均为7．5。淀粉酶的最适pH值均为6．5；纤维素酶在肝胰脏的最适pH值是4．8，在前肠、中肠、后肠均有两个峰值，分别为3．6和4．8。说明胰蛋白酶、脂肪酶、淀粉酶、纤维素酶分别适宜在弱碱性、弱碱性、弱酸性和酸性条件下发挥酶的活力。     

Characterization of digestive enzyme activity during larval development of gilthead seabream (Sparus aurata)

The evolution of the digestive enzyme equipment in seabream from hatching to 30 days old larvae was studied; there was a progressive increase in the activity of protease, amylase and acid and alkaline phosphatase from day 15 onwards. The use of specific inhibitors, and SDS-PAGE provided evidence to suggest that most of the proteases belonged to the serine group. A high -amylase activity was also denoted. Zymograms of larval extracts indicated that exogenous food has more a qualitative than a quantitative role in the secretion of digestive enzymes in this species.     

九孔鲍性腺发育过程中消化酶活力的变化

用酶学方法研究了性腺发育过程中九孔鲍肝胰腺和消化道中蛋白酶、淀粉酶和纤维素酶活力的变化。试验结果表明,雌、雄九孔鲍各消化酶活力均随着性腺发育呈先升后降的变化趋势。在性腺发育早期和晚期酶活力较低,在性腺发育中期酶活力显著升高,且均在成熟前期达到最高值。九孔鲍繁殖期各消化酶的活力分布存在器官特异性和性别差异,九孔鲍的淀粉酶和纤维素酶活力在各性腺发育期均表现为肝胰腺消化道,雌鲍雄鲍。同种消化器官内各消化酶的活力也存在差异,雌、雄九孔鲍繁殖期肝胰腺和消化道内各消化酶的最大活力均为:纤维素酶淀粉酶蛋白酶。     

饥饿对褐菖鲉消化道指数及消化酶活力的影响

在水温(18±0.5)℃、盐度27.0±0.5条件下,测定了褐菖鲉不同饥饿时间(0、3、7、14、21 d)的比肝质量、比胃质量、比幽门质量、比肠长及各消化组织消化酶活力。试验结果表明,在饥饿过程中,褐菖鲉消化道组织萎缩,比肝质量、比胃质量、比幽门质量和比肠长呈显著下降趋势(P<0.01),其中比肝质量下降速率最大,饥饿21 d的比肝质量比对照组下降85.033%。饥饿期间,蛋白酶活力总体呈先升后降的趋势,差异显著(P<0.05)。淀粉酶活力的变化趋势亦为先升后降,饥饿1 d,前、中、后肠、幽门的淀粉酶活力呈不同程度上升,之后,除胃和幽门外,随着饥饿时间的延长,皆呈下降趋势,与对照组相比,差异显著(P<0.05);脂肪酶活力总体呈缓慢下降趋势,差异不显著(P>0.05)。     

大黄鱼消化道菌群结构、消化酶和非特异性免疫酶活力分析

为研究大黄鱼(Larimichthys crocea)消化道的菌群结构、消化酶和非特异性免疫酶活力特征,本研究采用高通量测序技术系统分析大黄鱼胃、幽门盲囊和肠道中菌群组成及分布,并对比研究工厂化养殖和网箱养殖模式下的消化道菌群;同时,结合生化分析方法解析2种模式下消化道消化酶和非特异性免疫酶活力特征。结果显示,2种养殖模式下,菌群多样性随消化道延伸呈下降趋势;乳杆菌科(Lactobacillaceae(f))、Fructobacillus、黄杆菌属(Flavobacterium)等代表的菌属为共有优势菌群。其中,拟杆菌属(Bacteroides)和Anaerostipes等的丰度随消化道延伸呈下降趋势,而乳杆菌科、E01_9C_26_marine_group(o)所代表的菌属及黄杆菌属等则相反;普氏菌属(Prevotella_9)、乳杆菌科代表的菌属为2种模式养殖大黄鱼的主要差异菌属。工厂化养殖条件下,幽门盲囊和肠道中的菌群组成及其参与营养和免疫相关代谢通路的基因数目差异不显著(P>0.05),但与胃部的菌群组成和相关代谢通路基因数目存在明显差异;而网箱养殖大黄鱼胃部与幽门盲囊和肠道的菌群结构及相关代谢通路基因数目差异相对较小。2种养殖模式下的大黄鱼消化道菌群与饲料菌群相近。另外,胃和幽门盲囊也具有非特异性免疫酶活性,说明,整个消化道还具有一定的化学免疫屏障作用。本研究结果将为大黄鱼健康养殖提供基础参考,并为消化道菌群生理功能探讨提供理论依据。     

Stages of gonad development during the reproductive cycle of the blackfin snook, Centropomus medius Günther

The reproductive biology of the Blackfin snook Centropomus medius was studied to expand our current knowledge on its aquaculture potential. From April 2001 to November 2002, 301 females and 193 males were captured. A 1:1.6 (male:female) ratio was found. Gonadosomatic (GSI) and hepatosomatic (HSI) indices suggested that the spawning period (SP) extended from September to November, with peak spawning activity in September (GSI=0.98% and HSI=0.7%). The period of pre‐gametogenesis extended from January to June. During the post‐SP in December, 90% of oocytes were pre‐vitellogenic and 10% were atretic. Histological analysis of gonads (haematoxylin–eosin, Sudan black B, Alcian blue PAS, Cleveland Wolfe) showed five stages of oocyte development, each occurring at a characteristic range of oocyte diameters (μm): (I) pre‐vitellogenic (25–55); (II) cortical alveoli (56–250); (III) vitellogenic (251–340); (IV) maturation (341–645) and (V) atretic (21–100). Five reproductive stages were identified for testis morphology: (I) regressed; (II) early maturation; (III) mid‐maturation; (IV) full maturation and (V) regression. The type of ovarian development in C. medius was identified as a group synchronous.     

生物絮团对仿刺参幼参消化与免疫酶活性的影响

水温18.2-21.9 ℃和盐度30-32下,在室内200 L塑料水槽中添加不同的碳源（葡萄糖、蔗糖、玉米淀粉、地瓜粉等）形成生物絮团,养殖体重（0.9±0.1 ）g/只的仿刺参（Apostichopus japonicus ）幼参2个月,探讨水体中的生物絮团对其体内主要消化酶和免疫性酶活性的影响。结果表明,养殖水体中添加淀粉、蔗糖有利于提高幼参体内消化酶（淀粉酶、蛋白酶）的活性。复合碳源组（葡萄糖：果糖：蔗糖：玉米淀粉：地瓜粉=0:3:4:2:1）幼参胃蛋白酶活性（10.63 U/mg prot）显著高于其它组,复合碳源更利于提高幼参胃蛋白酶活性。复合碳源组（葡萄糖：果糖：蔗糖：玉米淀粉：地瓜粉=1:2:4:1:2）,幼参体壁中ALP活性最高,为2.66 U/mg;而玉米淀粉组中,幼参体液中SOD活性（204.66 U/mg ）显著高于其他各试验组（P < 0.05）。添加碳源后制得的生物絮团可以提高幼参机体的免疫功能。     

Digestive enzyme activity during larval development of the Senegal sole (Solea senegalensis)

The activities of the main digestive enzymes (proteases, amylase, lipase) as well as those of acid and alkaline phosphatases were assessed during the larval development of the Senegal sole, Solea senegalensis. Important variations in specific activities of all the enzymes were observed during the period of study and were mostly related to the beginning or the end of metamorphosis. Both acid and alkaline protease activities were identified at early stages of development. Acid proteases accounted for only 10% of total protease activity in a 9 days-old larva, but exceeded 75% in a 33 days-old individual. Maximum lipase activity was related to the development of exocrine pancreas (days 6 to 10) and to metamorphosis. It is suggested this can be related to the metabolism of lipid reserves taking place during this morphological change. Activity of alkaline phosphatase decreased from day 5 to day 20 but therafter revealed a sharp increase, possibly linked to the development of enterocytes. The pattern of development of the main digestive enzymes found in S. senegalensis is similar to that described in other flatfish species.     

间甲酚对杂交鲟幼鱼消化酶活性的影响

研究不同浓度间甲酚胁迫下杂交鲟幼鱼胃和肠中主要消化酶的活性变化情况,为了解间甲酚对鱼类幼鱼的潜在毒性作用提供参考。杂交鲟(施氏鲟Acipenser schrenckii♀×西伯利亚鲟A.baerii♂)幼苗平均体长(12.35±0.94)cm,平均体重(10.26±2.37)g。在水温(17.5±0.5)℃条件下,设置0.50、1.00、2.00、4.00和8.00 mg/L的间甲酚浓度梯度,采用生化和半静态亚急性毒性试验方法研究了杂交鲟幼鱼胃和肠中淀粉酶、脂肪酶、胃蛋白酶和胰蛋白酶的活性变化及间甲酚对4种酶活性的影响。结果显示:(1)在第20天时,胃中淀粉酶活性和胃蛋白酶活性随间甲酚浓度的增大呈"升高-降低"变化,第40天时2种酶活性呈显著下降变化(p0.05),而脂肪酶活性在第20天和第40天时均呈"升高-降低"变化。(2)在第20天和第40天时,肠中淀粉酶活性和胰蛋白酶活性随间甲酚浓度的增大呈"升高-降低"变化,而脂肪酶活性在第20天时呈"升高-降低"变化,在第40天时呈显著下降变化(p0.05)。低浓度间甲酚暴露对杂交鲟幼鱼肠和胃中消化酶活性有诱导作用,而高浓度有抑制作用,呈剂量-效应关系;在同一间甲酚浓度下,胃中胃蛋白酶和肠中脂肪酶活性随着时间的延长而降低,呈时间-效应关系。     

Characterization of chymotrypsin activity during early ontogeny of larval red drum (Sciaenops ocellatus)

The temporal evolution of chymotrypsin activity during early ontogeny of laboratory reared red drum larvae was accomplished using a combination of biochemical assays and electrophoretic methods (substrate SDS-PAGE). Optimal functional conditions for chymotrypsin were also determined. Chymotrypsin activity was first detected prior to the onset of exogenous feeding. Total chymotrypsin activity increased with age and standard length. Specific activity was greatest on day 10 post-hatch. Maximal chymotrypsin activity was observed at 50 °C, pH 7.8, and Ca²⁺ concentration of 25 mM. Using substrate gel electrophoresis and specific inhibitors the molecular weight of red drum chymotrypsin was estimated to be 26–27 kD. Our results indicate that the digestive system of red drum larvae is capable of alkaline proteolysis before first feeding and suggest that chymotrypsin may have potential as an indicator of nutritional condition.     

菊黄东方鲀当年鱼种养殖阶段消化酶活性研究

为了研究池塘养殖菊黄东方鲀（Takifugu flavidus）鱼种生长及肠组织中消化酶活性随生长的变化,2012年5－11月进行室外养殖试验,池塘面积0.2 hm2,水深1.5～2.0 m,鱼苗体长1.2~1.5 cm,放养密度为22.5 万尾/hm2,试验用海水盐度5~15,水温为15~35℃,pH 8~9;测定当年鱼种不同生长阶段的体长、体质量、肝重、肠长等生长指标,通过生物化学方法测定了其肠组织主要消化酶活性。结果表明,菊黄东方鲀幼鱼体长、体质量与养殖天数均呈指数相关（L=27.07e0.0088t, W=1.0982e0.0262t）;体长与体质量呈幂函数增长相关（W=3×10-5L3.1070）,且为异速生长。不同生长阶段菊黄东方鲀肝体比、比肠长、肥满度的变化显著（P<0.05）;肝体比随生长呈显著上升趋势（P<0.05）,变化范围为4.15%~20.23%;比肠长则呈显著下降趋势（P<0.05）,变化范围为0.97%～2.33%,不同生长阶段肥满度变化为3.99%～5.11%。菊黄东方鲀肠组织碱性蛋白酶和淀粉酶活性均随生长呈显著降低趋势（P<0.05）,最大值均出现在养殖40 d（83.11 U/mg与3.13 U/mg）;酸性蛋白酶活性呈先下降、后上升趋势（P<0.05）,最小值（0.34 U/mg）与最大值（0.86 U/mg）分别出现在113 d和166 d;脂肪酶活性随生长变化不显著（P>0.05）。研究表明,菊黄东方鲀鱼种的生长与养殖条件的改变存在密切关系;肝体比、比肠长等与鱼的发育及营养摄入存在一定关系;肠组织不是生成蛋白酶和淀粉酶的主要器官。     

Digestive enzyme activity of the red porgy (Pagrus pagrus, L.) during larval development under culture conditions

The ontogenic development of the main digestive enzymes (proteases, amylase and lipase) in the red porgy, Pagrus pagrus, larvae was assayed during the larval development. The green water technique was carried out for larval rearing and whole‐body homogenates were used for enzymatic assays in triplicate. Significant alterations in specific activities of all digestive enzymes measured during the period of this study were mostly related to metamorphosis and weaning. Trypsin‐ and chymotrypsin‐specific activities were first detected on day 3, together with opening of the mouth, and slightly increased until 25 days after hatching (DAH). After this period, the specific activities of these enzymes slightly decreased. Pepsin was first detected on day 28, concurrent with stomach formation, and a sharp increase was observed until 30 DAH. A slight decrease was measured from this date until the end of the experiment. Both amylase and lipase were measured for the first time on days 2 and 4 respectively, and the specific activities of these enzymes showed similar patterns during the first week of the study. Then, slight variations were observed until 30 DAH and while lipase‐specific activity declined, an increase in the specific activity of amylase was found until the end of the experiment. It is concluded that the variations observed in the specific activity of digestive enzymes were related to either metamorphosis, such as the formation of the stomach (28 DAH), or to changes in food composition. The profile of the developmental pattern of the main digestive enzymes detected in P. pagrus is similar to that described for other Sparid species.