黄条鰤仔稚幼鱼消化酶活性变化研究

为了解黄条鰤(Seriola aureovittata)早期发育阶段的消化生理特性,测定了黄条鰤胚胎、仔稚幼鱼阶段脂肪酶、淀粉酶、胰蛋白酶和碱性磷酸酶活性变化。结果显示,在黄条鰤仔鱼出膜前胚胎阶段,即能检测到脂肪酶、淀粉酶和碱性磷酸酶活性;初孵仔鱼体内(1 d)初次检测出胰蛋白酶的活性。脂肪酶和碱性磷酸酶比活力在仔鱼孵化后迅速增强(P<0.05),在4 d开口时,2种酶比活力达最高值;淀粉酶比活力在7 d时达最大值;胰蛋白酶比活力在仔鱼阶段缓慢上升,15 d时比活力最大。稚鱼阶段内脏团中脂肪酶、碱性磷酸酶和胰蛋白酶活性基本维持稳定,幼鱼阶段内脏团脂肪酶、碱性磷酸酶和胰蛋白酶活性都呈现上升趋势;稚鱼和幼鱼阶段内脏团中淀粉酶活性下降并基本稳定于较低水平。研究表明,黄条鰤仔稚幼鱼发育过程中,各种消化酶活性变化明显,且与其发育阶段和食性密切相关。在尚未摄食饵料的早期仔鱼体内已存在消化酶,认为其是母源传递而来,不是由外源性饵料所致;幼鱼阶段内脏团脂肪酶、碱性磷酸酶和胰蛋白酶比活力明显提高,这反映出随苗种生长发育,其肠道结构和消化机能逐渐完善,并且对脂肪、蛋白质的需求逐渐增强。     

黄条仔稚幼鱼消化酶活性变化研究

为了解黄条(Seriola aureovittata)早期发育阶段的消化生理特性,测定了黄条胚胎、仔稚幼鱼阶段脂肪酶、淀粉酶、胰蛋白酶和碱性磷酸酶活性变化。结果显示,在黄条仔鱼出膜前胚胎阶段,即能检测到脂肪酶、淀粉酶和碱性磷酸酶活性;初孵仔鱼体内(1 d)初次检测出胰蛋白酶的活性。脂肪酶和碱性磷酸酶比活力在仔鱼孵化后迅速增强(P<0.05),在4 d开口时,2种酶比活力达最高值;淀粉酶比活力在7 d时达最大值;胰蛋白酶比活力在仔鱼阶段缓慢上升,15 d时比活力最大。稚鱼阶段内脏团中脂肪酶、碱性磷酸酶和胰蛋白酶活性基本维持稳定,幼鱼阶段内脏团脂肪酶、碱性磷酸酶和胰蛋白酶活性都呈现上升趋势;稚鱼和幼鱼阶段内脏团中淀粉酶活性下降并基本稳定于较低水平。研究表明,黄条仔稚幼鱼发育过程中,各种消化酶活性变化明显,且与其发育阶段和食性密切相关。在尚未摄食饵料的早期仔鱼体内已存在消化酶,认为其是母源传递而来,不是由外源性饵料所致;幼鱼阶段内脏团脂肪酶、碱性磷酸酶和胰蛋白酶比活力明显提高,这反映出随苗种生长发育,其肠道结构和消化机能逐渐完善,并且对脂肪、蛋白质的需求逐渐增强。     

黄条鰤幼鱼胃排空特征、消化酶活性及摄食调控基因表达

为阐明黄条鰤幼鱼摄食消化特性，构建最佳胃排空数学模型，确立最适摄食投喂间隔，实验检测了黄条鰤幼鱼[(63.96±5.63) g]胃排空过程中内容物质量、肝脏和肠道中消化酶活性变化，分析了垂体中摄食调控相关基因的表达，比较了线性模型、平方根模型、立方模型3种数学模型对胃排空曲线的拟合程度。结果显示，黄条鰤在摄食后瞬时胃内容物湿重呈阶段性降低，18 h后降为0，属于直线下降型胃排空类型。胃排空过程中，肝脏淀粉酶、脂肪酶和糜蛋白酶活性呈先上升后下降、随后又上升接着下降的“M”型变化趋势，淀粉酶活性在摄食后0～6 h显著上升，脂肪酶和糜蛋白酶活性在0～9 h显著上升。三种酶活性在9～12 h均呈显著下降趋势，在15～18 h显著上升，且在18 h活性达到最高；肠道中的淀粉酶在0～6 h显著上升，随后下降，9～12 h呈上升趋势，12 h活性达到最高，随后逐渐下降，其脂肪酶和糜蛋白酶活性则是在摄食后0～12 h显著上升，12 h活性达到最高，随后逐渐下降。神经肽Y (npy)和食欲素(ore) mRNA表达水平呈先上升后下降趋势，npy在摄食后12～15 h内表达水平显著上升，ore在9～15 ...     

蓝宝石鱼仔稚鱼发育过程中各消化酶活性变化的研究

对蓝宝石鱼仔稚鱼从破膜至25日龄时的可溶性蛋白含量及各种消化酶活性进行了测定。结果表明,在仔鱼出膜后第1天,均能检测到活性,而胃蛋白酶活性在第613龄后才明显检测到,并趋于稳定。可溶性蛋白的含量随日龄的增加而增加。蛋白酶、淀粉酶、脂肪酶的活性随着仔稚鱼的发育而发生变化,其全活力与比活力呈现出不同的变化模式。蛋白酶比活力在仔鱼7日龄时达到最大值,之后随日龄的增加比活力降低,并趋于稳定。淀粉酶比活力从1日龄逐渐增加,至7日龄达到最大值,之后一直维持在一较低水平。脂肪酶的全活力与比活力呈现出完全不同的变化方式,全活力从3日龄到6日龄逐渐增加,到6层龄达到最大值,以后急剧下降;刚破膜时,比活力有较高的水平,后来始终降低．但在5～6日龄有所减缓。10日龄后脂肪酶的全活力、比活力都处于较低水平,12日龄时已经无法检出。蓝宝石鱼发育过程中,主要消化酶活性随着生长变化显著,反映蓝宝石鱼随生长其消化功能逐渐完善。     

鱼消化酶活性的研究

以体重320～350 g的(鱼免)鱼(Miichthys miiuy)为实验材料,研究(鱼免)鱼消化酶的分布及不同pH值条件下胃、肝胰脏、幽门、前肠、后肠中蛋白酶的活性.结果表明,蛋白酶在各消化器官的比活力顺序胃＞肝胰脏＞前肠＞幽门＞后肠,数值分别为439.75±6.82、404.46±11.64、255.42±2.41、123.23±0.46、49.39±2.81;淀粉酶比活力顺序为幽门＞肝胰脏＞前肠＞胃＞后肠,数值分别为3 107.82±84.57、2 420.72±52.85、2 336.15±10.57、1 617.34±31.71、1 247.36±21.14;脂肪酶比活力顺序肝胰脏＞幽门＞前肠＞后肠,数值分别为177.99±0.23、80.79±6.97、46.69±5.06、42.76±2.25.胃、肝胰脏、前肠、幽门、后肠的蛋白酶最适pH值分别是1.9、9.0、8.4、9.0、8.0.研究表明(鱼免)鱼的胃含有较高的胃蛋白酶及淀粉酶活性,在食物消化中起了重要作用.肝胰脏的蛋白酶、淀粉酶及脂肪酶的总酶活比其它消化器官都高,因此认为肝胰脏是消化酶的主要分泌器官.     

鮸鱼消化酶活性的研究

以体重320~350 g的鱼免鱼(Miichthys miiuy)为实验材料,研究鱼免鱼消化酶的分布及不同pH值条件下胃、肝胰脏、幽门、前肠、后肠中蛋白酶的活性。结果表明,蛋白酶在各消化器官的比活力顺序:胃>肝胰脏>前肠>幽门>后肠,数值分别为:439.75±6.82、404.46±11.64、255.42±2.41、123.23±0.46、49.39±2.81;淀粉酶比活力顺序为:幽门>肝胰脏>前肠>胃>后肠,数值分别为:3 107.82±84.57、2 420.72±52.852、336.15±10.57、1 617.34±31.71、1 247.36±21.14;脂肪酶比活力顺序:肝胰脏>幽门>前肠>后肠,数值分别为:177.99±0.23、80.79±6.97、46.69±5.06、42.76±2.25。胃、肝胰脏、前肠、幽门、后肠的蛋白酶最适pH值分别是1.9、9.0、8.4、9.0、8.0。研究表明:鱼免鱼的胃含有较高的胃蛋白酶及淀粉酶活性,在食物消化中起了重要作用。肝胰脏的蛋白酶、淀粉酶及脂肪酶的总酶活比其它消化器官都高,因此认为肝胰脏是消化酶的主要分泌器官。     

黄鳍鲷主要消化酶活性在消化道不同部位的比较研究

研究了黄鳍鲷（Sparus latus Houttuyn）主要消化酶（蛋白酶、淀粉酶、脂肪酶）在消化道不同部位（肝胰脏、胃、前肠、中肠、后肠）的分布情况。结果表明，蛋白酶、淀粉酶、脂肪酶比活最高的部位分别是胃、肝胰脏和前肠，酶活性明显高于其他部分（P〈0．01）。从肠道消化酶的比活大小来看，蛋白酶比活是前肠、中肠、后肠依次降低，淀粉酶比活是中肠〉前肠〉后肠，脂肪酶比活是前肠〉后肠〉中肠。     

野生和养殖鲻消化酶活性的比较研究

对野生鲻(Mugil cephalus)和养殖鲻的消化道指数及淀粉酶和蛋白酶活性分布进行了比较研究,并探讨了不同温度和pH对离体状态下消化道淀粉酶和蛋白酶的影响.结果表明,野生鲻和养殖鲻的比内脏重、比肝重、比胃重、比肠长分别为0.043±0.001和0.0480±0.004,0.009±0.001和0.007±0.000,0.008±0.002和0.007±0.000,2.886±0.301和3.158±0.141.野生鲻的蛋白酶和淀粉酶活力在各消化器官中的分布与养殖鲻间存在差异.野生鲻和养殖鲻比较,野生鲻各消化器官中淀粉酶活力均极显著高于养殖鲻(P<0.01);蛋白酶活力在肝胰脏和胃中差异不显著(P>0.05),在中肠差异显著(P<0.05),在前肠和后肠差异极显著(P<0.01).在肝胰脏、胃、前肠、中肠、后肠和幽门盲囊6部位,野生鲻淀粉酶的最适温度分别是40℃、45℃、45℃、45℃、40℃、45℃;养殖鲻淀粉酶的最适温度分别是40℃、40℃、40℃、45℃、40℃、40℃.野生鲻淀粉酶最适pH在肝胰脏为6.2,在其余各部分均是7.2;养殖鲻淀粉酶最适pH在胃和前肠为2.2和8.0,在其余各部分均为7.2.野生鲻蛋白酶最适温度在肝胰脏、胃、前肠和后肠均为45℃,在中肠为50℃;养殖鲻蛋白酶最适温度在肝胰脏、胃和中肠为40℃,前肠和后肠为45℃.野生和养殖鲻蛋白酶的最适pH胃部为3.2,其余各部分的最适pH均是7.2.     

(鱼免)鱼消化酶活性的研究

以体重320～350 g的(鱼免)鱼(Miichthys miiuy)为实验材料,研究(鱼免)鱼消化酶的分布及不同pH值条件下胃、肝胰脏、幽门、前肠、后肠中蛋白酶的活性.结果表明,蛋白酶在各消化器官的比活力顺序:胃＞肝胰脏＞前肠＞幽门＞后肠,数值分别为:439.75±6.82、404.46±11.64、255.42±2.41、123.23±0.46、49.39±2.81;淀粉酶比活力顺序为:幽门＞肝胰脏＞前肠＞胃＞后肠,数值分别为:3 107.82±84.57、2 420.72±52.85、2 336.15±10.57、1 617.34±31.71、1 247.36±21.14;脂肪酶比活力顺序:肝胰脏＞幽门＞前肠＞后肠,数值分别为:177.99±0.23、80.79±6.97、46.69±5.06、42.76±2.25.胃、肝胰脏、前肠、幽门、后肠的蛋白酶最适pH值分别是1.9、9.0、8.4、9.0、8.0.研究表明:(鱼免)鱼的胃含有较高的胃蛋白酶及淀粉酶活性,在食物消化中起了重要作用.肝胰脏的蛋白酶、淀粉酶及脂肪酶的总酶活比其它消化器官都高,因此认为肝胰脏是消化酶的主要分泌器官.     

泥鳅消化道指数及消化酶活性分布的研究

研究了泥鳅消化道指数及消化酶活性在肠道不同部位(前肠、中肠及后肠)和肝胰脏的分布.试验结果表明,泥鳅比肠长为0.335±0.006,比肠质量为0.021±0.002,比肝质量为0.015±0.001,其特征偏肉食性.泥鳅肝胰脏淀粉酶、蛋白酶和脂肪酶的活性均极显著高于其他部位,分别为(45.464±2.442)、(580.515±12.282)、(28.889±3.849) U/ml.     

Karyotype analysis of the yellowtail kingfish Seriola lalandi lalandi (Perciformes: Carangidae) from South Australia

The karyotype and chromosomal characteristics of the yellowtail kingfish Seriola lalandi lalandi were investigated by examining metaphase spreads from kidney cells of 4-month-old fish artificially bred using wild-captured broodstock from the coast of South Australia. A total of 80 mitotic metaphases from 10 individual fish were analysed, with 52 spreads having a mode of 2 n =48 chromosomes, representing 65% of the metaphases observed. The diploid consisted of two metacentric, two submetacentric, six subtelocentric and 38 telocentric chromosomes, with the fundamental number of chromosome arms being 52. The total haploid chromosome length was approximately 44.412 μm. This study shows that the karyotype of S. lalandi lalandi differs from those reported previously for other Seriola species in having one pair of metacentric chromosomes.     

中华蛸消化系统组织学结构及消化酶活性研究

为探明中华蛸(Octopus sinensis)的消化机能,明确适宜的投喂频率,减少互残造成的经济损失,本研究对中华蛸消化系统各器官进行组织学观察,并比较了摄食前后各消化器官消化酶活性以及机体营养物质的代谢水平的变化。结果显示,中华蛸嗉囊、胃、盲囊和肠由黏膜层、黏膜下层和肌层组成,内壁含有较多的褶皱,胃壁肌层最发达,盲囊和肠黏膜褶皱层无护膜;前唾液腺和后唾液腺均为复合管状腺,由腺管及大量的分泌导管组成;肝脏内肝小叶界限不易分辨。中华蛸摄食后,胰蛋白酶活性显著高于脂肪酶和淀粉酶活性。肝脏是分泌消化酶的重要器官,胰蛋白酶活性在肝脏最高为(148.74±21.25) U/mg,淀粉酶和脂肪酶活性在肝脏和胃最高。摄食后血浆总蛋白在120 min达到最低值后上升,血糖和肌糖原浓度在200 min达到最大值后下降,血浆胆固醇和血浆甘油三酯浓度变化幅度较小。消化过程分为2个阶段：第1阶段食物进入嗉囊和胃部,肝脏分泌大量胰蛋白酶,机体的营养物质为消化过程供能,含量下降;第2阶段胰蛋白酶活性处于较高水平,营养物质逐步被消化吸收。中华蛸完整的消化吸收过程约400 min,研究表明,中华蛸养殖生产中适宜的投喂间隔时间为6~7 h。     

Effect of reward level on the number of food demands in yellowtail Seriola quinqueradiata

ABSTRACT: The effect of reward level (amount of food received in response to one trigger actuation) on the self-feeding activity of juvenile yellowtails was examined. Three groups of 10 juvenile yellowtails (mean bodyweight, 65.6 g) were allocated randomly to three 200 L cylindrical tanks set in the experiment room. Each tank was illuminated by overhead fluorescent lamps with a light : dark photoperiod regimen of 12 h : 12 h (light 06.00–18.00 hours). A rod-type tactile switch was used to activate the self-feeding device. Three levels of reward were set up by installing a different number of identical feeders for each group: one feeder for the low-reward group, three feeders for the medium-reward group and five feeders for the high-reward group. Each feeder delivered 3–7 pellets per actuation. Yellowtails in all groups showed a clearly diurnal feeding pattern that was synchronized to the given photoperiod. Average number of feeder actuations per day was highest (219/day) in the low-reward group. Second highest was the medium-reward group (116/day), and last was the high-reward group (67/day). The resultant average feed intake per day was 27.1 g/day in the low-reward group, 31.5 g/day in the medium-reward group and 28.4 g/day in the high-reward group. Thus, yellowtails appear to have the ability to regulate the amount of feed delivered daily by increasing the number of food demands when the reward is low and decreasing the number of food demands when the reward is high.     

Comparative study of digestive enzymes in fish with different nutritional habits. Proteolytic and amylase activities

This work provides a comparative study of the proteolytic and amylase activities in six species of fish with different nutritional habits: rainbow trout (Oncorhynchus mykiss), gilthead seabream (Sparus aurata), European eel (Anguilla anguilla), common carp (Cyprinus carpio), goldfish (Carassius auratus), and tench (Tinca tinca). Trout and carp showed the highest digestive proteolytic activity. When proteolytic activity was determined in a wide range of pHs, the highest values in the digestive tract of all species were found at alkaline pHs, except in eel where activity could be detected only at acid pHs. Eel showed the lowest digestive proteolytic potential among all the species studied. With respect to amylase activity, the omnivorous species presented higher activity than did the carnivores. Among the carnivorous species, the lowest activity was found in trout. The ratio of total amylase:total proteolytic activity was higher in omnivorous fish species, the carp having the greatest value, whereas in trout this ratio was lower than one. Digestive enzyme activity declined as the incubation temperature decreased, but this trend varied depending on the fish species and the tissue analyzed.     

黄条鰤生长性状全基因组关联分析

利用2b-RAD技术对119尾黄条鰤(Seriola lalandi)个体进行测序,共获得黄条鰤SNP分子标记26665个,对黄条鰤个体的体质量和全长这2个重要生长性状进行全基因组关联分析,筛选与体质量和全长性状相关的SNP位点和候选基因。结果显示,黄条鰤体质量性状中共筛选到17个体质量显著关联的SNP位点,找到17个可能的候选基因,全长性状共筛选到12个潜在显著关联位点,找到12个可能的候选基因。利用KEGG数据库对可能的候选基因进行Pathway分析,得知候选基因主要参与了细胞或组织生长发育相关的代谢通路调控过程,可能是影响黄条鰤生长性状密切相关的重要候选SNP位点和功能基因,结果可为今后黄条鰤种质资源可持续利用和育种提供遗传信息资料积累。     

Temperature and dissolved oxygen influence growth and digestive enzyme activities of yellowtail kingfish Seriola lalandi (Valenciennes, 1833)

A 5 week experiment was carried out with juvenile yellowtail kingfish Seriola lalandi to investigate the interactive effects of water temperature (21, 24, or 27°C) and dissolved oxygen regime (normoxic vs. hypoxic) on the growth rate, feed intake and digestive enzyme activity of this species. Specific growth rate (SGR) was highest at 24°C, regardless of oxygen regime, but the SGRs of the fish exposed to hypoxia at 21, 24 and 27°C were 13%, 20% and 17% lower, respectively, than the SGRs recorded for the fish reared under normoxic conditions. The digestive enzyme activities (i.e. trypsin, lipase and α‐amylase) were influenced by temperature but did not appear to be affected by dissolved oxygen concentration. Information about the effects of water temperature and dissolved oxygen on feeding, growth and digestive capacity of juvenile yellowtail kingfish could contribute to improving feed management decisions for production of this fish species under different environmental conditions.     

Effects of illumination on early life development and digestive enzyme activities in common pandora Pagellus erythrinus L. larvae

The activities of main digestive enzyme (proteases, amylase and lipase) and animal husbandry (mainly growth and survival) were studied in common pandora Pagellus erythrinus larvae until 30 days after hatching (DAH). Three different illumination levels (10, 30 and 100 lx) were compared in triplicate and green water technique was carried out. At the end of the experiment, illumination did not affect neither survival nor growth except 10 lx treatment. Similarly, specific growth rate (SGR) was different in 10 lx treatment (p < 0.05), although no differences were found in group 30 and 100 lx treatments (p > 0.05). In all groups, trypsin and chymotrypsin specific activities were firstly detected on day 3 related with mouth opening and slightly increased until 20 and 25 DAH respectively, and after this date specific activities of those decreased. Although, there was a significant difference between 10 lx treatment and other experimental groups (p < 0.05), no differences were found in other treatments (p > 0.05). Pepsin was firstly detected on day 25 related with stomach formation and sharp increase was observed until 30 DAH and then slight decrease was measured from this date and no differences were found between all groups. Amylase was firstly determined on day 2 and increased to day 5. After this date, slight decreases were measured in all groups and continued until end of experiments. The highest specific activity of amylase was determined in 30 lx treatment and no significant differences were found between groups (p > 0.05). Lipase was firstly detected on day 4 and increased to day 10. Then, activity of lipase decreased until day 15 and increased again until 25 DAH. Slight decreases were found in all groups until day 30 and continued to end of experiments. No significant differences were detected among groups (p > 0.05).

Finally, the significant improvement in survival, larval development and specific enzyme activities of larvae were determined in 30 lx treated group. It is thought that this phenomenon is related to optimal keeping conditions provided by the medium illumination level for Pagellus erythrinus larvae.