首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 234 毫秒
1.
为探讨温度胁迫对刺参基因表达的影响,从已构建的刺参耐寒基因筛选cDNA文库中选取差异基因主要卵黄蛋白(major yolk protein,MYP):MYP1和MYP2,利用实时荧光定量PCR研究了其在刺参胚胎发生和个体发育9个阶段(受精卵、囊胚期、原肠期、小耳状幼体、中耳幼体、大耳幼体、樽形幼体、五触手幼体和稚参)、成体7种组织(呼吸树、体腔液、肠、纵肌、体壁、雄性性腺和雌性性腺)、长时温度胁迫(20℃、4℃,30 d)和低温短时胁迫(7℃、4℃、1℃、-2℃,12 h)成体肠组织中的表达量。结果发现,MYP1和MYP2表达模式基本相同:(1)在胚胎发育阶段樽形幼体时期开始表达,随后的阶段持续表达,到稚参阶段表达量最高;(2)在7种组织中,肠中的表达量最高,在体腔液中基本不表达,其余组织中均有表达;(3)在长时(30 d)温度胁迫下,肠组织中MYP表达量由高到低依次为4℃、12℃、20℃,且在4℃的表达量为20℃的6倍左右;(4)在低温短时胁迫(1℃、-2℃,12 h)条件下,肠组织中MYP表达量受到显著抑制,约为常温条件下的一半。研究表明,MYP在刺参胚胎发育的樽形幼体阶段开始合成,成体合成部位主要为肠,水温过低会抑制其表达。  相似文献   

2.
中间球海胆乳酸脱氢酶基因克隆及其对海水酸化的响应   总被引:1,自引:0,他引:1  
为明确中间球海胆乳酸脱氢酶(LDH)基因序列及表达特征,研究其对海水酸化胁迫的响应,实验利用cDNA末端快速扩增(RACE)技术获得中间球海胆LDH基因(命名为SiLDH)的全长cDNA,并且比较了海水酸化胁迫下,中间球海胆不同组织SiLDH基因表达及总LDH活性的变化情况。结果显示:①SiLDH基因的cDNA全长为1 499 bp,包含133 bp的5′非编码区,349 bp的3′非编码区和1 017 bp编码338个氨基酸的开放阅读框(ORF)。SiLDH编码蛋白的相对分子量为36.40 ku,理论等电点为6.55,属于无信号肽的非跨膜、温和疏水蛋白。②生物信息学分析显示,SiLDH蛋白序列与紫球海胆LDH X4蛋白序列一致性最高(90.88%)。③实时荧光定量PCR(qRT-PCR)发现,SiLDH基因在检测的4种组织中均有表达,相对表达量从高到低为性腺管足肠体腔液;总LDH活性检测显示,中间球海胆总LDH活性从高到低为性腺管足体腔液肠;④海水酸化处理60 d后发现,与自然海水组(pH 8.06±0.01)相比,SiLDH基因在中间球海胆性腺、管足和肠道中呈现总体降低趋势,在体腔液中则呈现随海水pH降低先降低后显著升高的趋势;总LDH活性在性腺、管足和体腔液中呈现随海水pH降低而降低的趋势,在肠道中则呈现随海水pH降低先降低后显著升高的趋势。研究表明,中间球海胆面对海水酸化时可能通过调节SiLDH基因的表达和LDH活性来缓解海水酸化带来的负面影响。  相似文献   

3.
为探讨水温对糙海参(Holothuriascabra)幼参生长、抗氧化酶及免疫酶活力影响,选择体重为(1.70±0.24)g的糙海参幼参,在低温组(23℃)、对照组(28℃)和高温组(33℃)温度控制养殖箱中养殖30 d,每10 d测定其特定生长率(SGR),体壁、体腔液、肠道及呼吸树中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、碱性磷酸酶(AKP)、溶菌酶(LZM)活力和丙二醛(MDA)含量。结果显示:(1) 30 d时对照组幼参SGR显著高于高温组和低温组(P<0.05),且高温组显著高于低温组(P<0.05),说明长期低温对幼参影响大于长期高温。(2)在低温组, 0 d时幼参体腔液中SOD、AKP、LZM活力以及MDA含量与对照组间无显著差异, 30 d时SOD、CAT以及AKP活力显著高于对照组(P<0.05);0 d时体壁中SOD、CAT、LZM活力以及MDA含量与对照组间无显著差异, 30 d时SOD、CAT活力以及MDA含量显著高于对照组(P<0.05); 0 d时肠道中除MDA含量外,所有酶活力显著高于对照组(P<0.05), 30 d...  相似文献   

4.
采用海藻酸钠(Na Alg)-HCG缓释制剂进行激素埋植实验。实验开始时,雌性金鱼(Carassius auratus)卵母细胞处于Ⅲ期。实验期间记录雌性金鱼性腺发育、放免(RIA)法测定血清性激素含量并且通过RT-PCR检测激素相关基因表达。结果表明,埋植Na Alg-HCG缓释激素后,雌性金鱼性成熟系数(GSI)在6-21 d显著高于对照组,血清睾酮(T)和雌二醇(E2)水平在6-30 d显著高于对照组;性腺芳香化酶基因(CYP19A基因)和雌激素受体基因(ERα基因)m RNA相对表达量分别在2-21 d、14-30 d内显著高于对照组,其性腺GH基因m RNA相对表达量变化不显著。研究结果显示,一次性埋植Na Alg-HCG缓释制剂,与雌性金鱼繁殖相关的生物学指标、激素水平、基因表达量较对照组产生明显变化,同时这种缓释制剂可以作为埋植激素的载体。  相似文献   

5.
采用海藻酸钠(Na Alg)-HCG缓释制剂进行激素埋植实验。实验开始时,雌性金鱼(Carassius auratus)卵母细胞处于Ⅲ期。实验期间记录雌性金鱼性腺发育、放免(RIA)法测定血清性激素含量并且通过RT-PCR检测激素相关基因表达。结果表明,埋植Na Alg-HCG缓释激素后,雌性金鱼性成熟系数(GSI)在6-21 d显著高于对照组,血清睾酮(T)和雌二醇(E2)水平在6-30 d显著高于对照组;性腺芳香化酶基因(CYP19A基因)和雌激素受体基因(ERα基因)m RNA相对表达量分别在2-21 d、14-30 d内显著高于对照组,其性腺GH基因m RNA相对表达量变化不显著。研究结果显示,一次性埋植Na Alg-HCG缓释制剂,与雌性金鱼繁殖相关的生物学指标、激素水平、基因表达量较对照组产生明显变化,同时这种缓释制剂可以作为埋植激素的载体。  相似文献   

6.
光棘球海胆的主要卵黄蛋白cDNA序列分析   总被引:3,自引:1,他引:3       下载免费PDF全文
提取成熟光棘球海胆(Strongylocentrotus nudus)性腺中的RNA做模板,根据NCBI数据库中已知海胆(编号:AB097218、AB192414、AY090112)主要卵黄蛋白MYP cDNA保守序列设计引物,用LA PCR方式分段扩增并测序得到了光棘球海胆MYP cDNA的全序列。扩增的cDNA全长4 061 bp,包含4 047 bp的开放阅读框,共编码1 349个氨基酸。用CluxtalX1.83对光棘球海胆与其他几种已知海胆MYP cDNA及推导的氨基酸序列进行比对,用Mega3.01计算遗传距离及构建进化树,结果表明,光棘球海胆与其他7种海胆的MYP具有高度的同源性。从氨基酸水平上看,光棘球海胆与红海胆(Pseudocentrotus depressus)亲缘关系最近,遗传距离为0.069±0.01;与同科的马粪海胆(Hemicentrotus pulcher-rimus)、紫球海胆(S.purpuratus)、中间球海胆(S.intermedius)的遗传距离分别是0.095±0.012、0.098±0.011和0.101±0.012;与白棘三列海胆(Tripneustes gratilla)、拟球海胆(Paracentrotus lividus)及绿海胆(Lytechinus variega-tus)亲缘关系相对较远,遗传距离分别是0.216±0.017、0.218±0.017和0.535±0.028。获得光棘球海胆MYP cDNA序列可为进一步研究MYP基因的功能和系统的进化分析奠定基础  相似文献   

7.
为研究虾夷马粪海胆体液免疫机理,测定其体腔液吞噬细胞在不同介质中对不同处理的酵母细胞的吞噬作用。对其无细胞体腔液、从调理及非调理酵母细胞分离出的成分进行SDS-PAGE分析,同时对无细胞体腔液进行透析、SephadexG-200凝胶层析和SDS-PAGE分析,在等渗缓冲液和酵母细胞吸附的无细胞体腔液中,测定不同调理素样分子浓度和不同反应时间时吞噬率的变化。结果显示,吞噬细胞在3种介质:等渗缓冲液、酵母细胞吸附的无细胞体腔液和无细胞体腔液中对非调理酵母细胞吞噬率之比为1.00∶1.11∶1.94,在等渗溶液中对调理酵母细胞的吞噬率是非调理酵母细胞的1.61倍;从调理酵母细胞分离出的成分在SDSPAGE中显示一条调理素样分子带,分子量为250.62 ku。经透析和SephadexG-200凝胶层析后,测得纯化的调理素样分子的分子量为250.62 ku;在所测试的浓度范围内,调理素样分子浓度越大,吞噬活性越高,且5.0和10.0μg/mL组在各个测试时间均比对照组高。在等渗缓冲液中,反应30 min时,10.0和5.0μg/mL组与对照组均有极显著差异(P0.01),在酵母细胞吸附的无细胞体腔液中,反应30 min时,10.0μg/mL组与对照组有显著差异(P0.05)。结果表明,在虾夷马粪海胆体腔液中发现一种调理素样分子,分子量约为250.62 ku,一定浓度的调理素样分子能显著提高虾夷马粪海胆体腔液吞噬细胞的吞噬活性。  相似文献   

8.
本实验研究了饲料中添加酵母多糖(6.3 g/kg)、马氏副球菌(109 cfu/kg)、大黄(25.0 g/kg)和氟苯尼考(15.0 mg/kg)4种添加物对仿刺参[初始体质量(4.68±0.36)g]非特异性免疫力以及肠道组织免疫相关基因Aj-p105、Aj-p50、Aj-rel和Aj-lys mRNA表达的影响.每个处理分别设置5个重复,以投喂未添加上述任何成份的基础饲料组作为空白对照,养殖实验周期为60 d.结果发现,饲料中添加马氏副球菌能显著提高仿刺参体腔细胞的吞噬活性和呼吸爆发活力,而添加酵母多糖可以显著提高仿刺参体腔细胞的吞噬能力,但是添加氟苯尼考显著降低了仿刺参体腔细胞的呼吸爆发活力;而在仿刺参中肠肠道组织中,酵母多糖和马氏副球菌处理组免疫基因Aj-p105和j-p50 mRNA的表达均大幅上调,显著高于对照组.其中,酵母多糖添加组增幅分别为43.2%和63.1%,马氏副球菌添加组的增幅分别为49.8%和48.0%.马氏副球菌添加组中免疫基因Aj-lys的表达显著高于对照组,增幅为46.4%;大黄添加组中Aj-p105 mRNA的表达量显著高于对照组,而氟苯尼考添加组中Aj-p50、Aj-rel和Aj-lys的mRNA表达量相对于对照组均显著下降.研究表明,饲料中适当添加酵母多糖和马氏副球菌可有效提高仿刺参非特异性免疫力,而饲料中抗生素氟苯尼考的添加会降低仿刺参非特异性免疫力.  相似文献   

9.
为研究促卵泡激素受体基因(FSHR)在施氏鲟(Acipenser schrenckii)性腺分化过程中的表达、分布及调控作用,采用反转录聚合酶链式反应(RT-PCR)和RACE技术克隆得到施氏鲟促性腺激素(FSHR)基因的全长cDNA序列,并对其编码氨基酸序列的特征、基因表达及调控作用进行了分析。结果显示:施氏鲟FSHR基因的cDNA全长为2696 bp,编码661个氨基酸,属于含有信号肽、跨膜结构且分泌到细胞外的疏水性蛋白。氨基酸同源性及进化分析表明,施氏鲟与小体鲟(A.ruthenus)FSHR序列一致性最高,亲缘关系最近。PCR结果显示,FSHR mRNA的表达具有广泛性,各组织中均有表达,但在性腺、垂体中的表达量较高,显著高于其他组织中的表达量。LHRH-A注射实验显示:不同浓度组中,施氏鲟性腺组织中FSHR mRNA的表达量呈先升高后降低的变化趋势;与对照组相比,1μg/kg组在诱导3 d时性腺组织中FSHR mRNA的表达量达到最高,极显著高于3μg/kg和5μg/kg组。与性腺组织中FSHR mRNA表达模式不同,垂体中FSHR mRNA的表达呈升高后降低趋势,3μg/kg组在注射后第3天达最大值。综上结果表明,LHRH-A可通过调控FSHR的表达参与施氏鲟的早期性腺发育。  相似文献   

10.
为探究怀山药皮(Chinese yam peel,YP)对淇河鲫免疫的影响,选取平均体重为(106.76±3.74)g的淇河鲫240尾,随机分为对照组(NC)、0.5%怀山药皮添加组(LYP)、1%怀山药皮添加组(MYP)、2%怀山药皮添加组(HYP)4组,养殖8周,检测实验鱼生长指标、血清生化指标及免疫相关基因的表达情况。结果显示:添加怀山药皮对淇河鲫生长指标没有显著性影响;血液生化指标中谷草转氨酶活性在MYP组显著性降低,碱性磷酸酶的活性显著升高;与NC组相比,怀山药皮添加组肝脏细胞膜与核膜完整性增强,胞质破碎,核溶解、偏移现象减轻;与NC组相比,添加怀山药皮上调了抑炎因子(IL-10)、紧密连接蛋白基因(Claudin-1)、抗氧化基因(CAT和GST)和TLR通路基因(TLR4)mRNA表达量。以上结果表明,饲料中添加怀山药皮,能在一定程度上增强鱼体免疫力。  相似文献   

11.
Juvenile green sea urchins, Strongylocentrotus droebachiensis, with an initial mean test diameter of 9.5 mm (±1.2 SD) were held in the laboratory, in individual compartments and at constant temperatures (8.5 C) (n = 90) for a period of 99 wk. The animals were supplied with flow‐through sea water, and fed the Nofima sea urchin manufactured feed ad libitum. Growth, survival, feed intake, feed conversion ratio (FCR), and gonad index (GI) of the sea urchins were monitored during this period. The mortality was 11% throughout the experimental period. The test diameter (TD) increased significantly with time, best described by a polynomial equation (TD = 0.8756 + 0.584Time − 0.002Time2, R2 = 0.995). Sex was included as dummy variable, but did not contribute significantly; hence, there were no differences in growth trajectories between males and females. The study showed there were no significant differences in body wet weight or FCR between males and females. However at the end of the experiment the female urchins had a significantly higher GI of 31.1% (±4.4), compared with the male urchins which had an average GI of 26.8% (±5.4). In conclusion, the present study showed that male and female green sea urchins have the same growth capacity and feed convention ratio but by the end of the experiment the gonad index was significantly higher in female than male urchins.  相似文献   

12.
13.
We compared the gonad-enhancing effects of two diets (NIWA and NIFA diets) in two size classes of sea urchins (Evechinus chloroticus): small and large urchins with a test diameter of 75.6 ± 1.2 mm and 93.8 ± 0.5 mm, weighing 174.8 ± 7.9 g and 315 ± 5.6 g, respectively. After eight weeks being fed prepared diets, urchin gonad index (GI) had significantly surpassed that of the initial and final samples of wild urchins. Urchins in the NIWA/small treatment had a larger GI than the NIFA/small and NIFA/large treatments. The NIWA/large treatment had a larger GI than the NIFA/large treatment. The overall percentage increase in GI for the NIWA/small, NIWA/large, NIFA/small and NIFA/large treatments were 183%, 135%, 132% and 85%, respectively. In terms of gonad colour (CIELAB), there were no significant differences in gonad redness (a*) or yellowness (b*) between experimental treatments, but there was a significant difference in gonad lightness (L*) with small urchins fed both diets having lighter-coloured gonads than the large urchins fed both diets. Sensory assessment of gonads revealed that gonads from small urchins fed both diets were rated as being of better colouration and more uniform in colour than gonads from large urchins. Gonads of urchins fed the NIFA diet were rated as being less bitter and of better overall taste than gonads from urchins fed the NIWA diet. This study shows that feeding prepared diets to E. chloroticus can significantly increase gonad yield but that different diets can affect the magnitude of GI increase and the taste of gonads, and that smaller urchins appear more suitable for gonad enhancement.  相似文献   

14.
Juvenile Strongylocentrotus droebachiensis (average wet weight = 4.0 g) were held at three initial stocking densities (15, 30 and 60 animals per tray, which equates to 0.25, 0.5 and 1 kg sea urchins/m2 surface area, respectively) under constant light and temperature conditions (LD 24:0 and 8.8°C) for 380 days. The somatic growth and survival of the urchins were monitored during this period, and the gonad index (GI) was measured at the conclusion of the experiment. The sea urchins in the two lowest stocking density groups had 100% survival after 380 days in contrast to the highest stocking density group, which only had 67% survival at the conclusion of the experiment. Somatic growth was significantly higher in the lowest density group than in the medium density group, and this in turn was significantly higher than in the high-density group. The injury occurrence was highest in the high-density group (20%), lower in the medium group (7%), and there were no injuries observed (0%) in the low density groups. There were no significant differences in GI between the groups at the end of the experiment. In conclusion, the present study showed that stocking density has significant effects on somatic growth and survival of juvenile green sea urchin, S. droebachiensis and should be taken into consideration when designing sea urchin holding systems.  相似文献   

15.
The nutritive values of three pelleted prepared diets, based on animal (AP), vegetable (VP) and yeast protein (YP) were studied for the sea urchin Heliocidaris erythrogramma (Val.). Fresh macroalga Ulva australis was used as a natural control diet. Triplicate groups of five animals were fed one of the four diets ad libitum every second day for 85 days. Sea urchins fed pelleted feeds had significantly higher food consumption rates (dry basis) and significantly lower total and protein absorption efficiencies compared with the algal diet. The gonad yield and gonad production efficiency in sea urchins fed the natural diet were significantly higher compared with initial group (gonad yield only) and urchins fed animal and vegetable diets, but did not differ significantly from those of the animals fed the yeast diet. Percent protein and lipid in the gonads were not affected by the dietary source. The taste and smell of gonads were generally better in sea urchins collected from the wild or fed yeast and natural diets than in sea urchins fed animal and vegetable diets. The animal protein diet was the most stable in seawater while the yeast protein diet had the poorest water stability. The results of this study suggest that development of a more stable, single‐cell, protein‐based diet has a potential to promote gonad production of H. erythrogramma.  相似文献   

16.
为探究仿刺参幼参对亮氨酸的最适需求量,在基础饲料中分别添加0.00%、0.80%、1.60%、2.40%、3.20%和4.00%的包膜亮氨酸,配成亮氨酸含量分别为1.29%(D1,对照组)、1.63%(D2)、1.98%(D3)、2.22%(D4)、2.58%(D5)和2.97%(D6)的6组实验饲料,饲喂初始体质量为(16.40±0.14) g的仿刺参幼参60 d。结果显示,(1)随饲料亮氨酸含量从1.29%提高到1.98%,仿刺参幼参的增重率和特定生长率显著升高,在D3组增重率达到最大值100.84%,随亮氨酸含量进一步提高,增重率和特定生长率显著降低,但D3、D4和D5组增重率和特定生长率还是显著高于对照组;(2)随饲料亮氨酸含量从1.29%提高到1.98%,仿刺参体壁的粗脂肪含量显著升高,在D3组达到最大值5.50%,且显著高于其他组,随亮氨酸含量进一步提高,仿刺参体壁粗脂肪含量显著降低,各组间水分、粗蛋白质和粗灰分含量均无显著性差异;随饲料亮氨酸含量的升高,仿刺参体壁蛋氨酸含量显著提高;(3)随饲料亮氨酸含量从1.29%提高到1.98%,仿刺参肠道脂肪酶和蛋白酶活性显著提高,...  相似文献   

17.
Sea urchins were stocked at a density of 15 (D15), 30 (D30), 45 (D45) and 60 (D60) urchins/cage (0.3 m long × 0.2 m wide × 0.4 m high) in a laboratory culture environment for 16 months. The wet body weight (BW) and test diameter growth were monitored at 2-month intervals during the experiment. At the conclusion of the experiment, the surviving sea urchins were counted and the gonad wet weight (GW) and gonad color were measured. Specific growth rate (SGR) of body weight, survival rate (SR), gonad index (GI), gonad color difference (ΔE 00), coefficients of variation (CV) of BW, GW, GI and ΔE 00, total biomass yield (TY) and total gonad yield (TGY) per cage were calculated. Two marketable yield variables, graded according to gonad index, i.e., marketable biomass yield (MY) and marketable gonad yield (MGY), were also calculated. Coefficient of variation of final body weight (FW) and final test diameter (FTD) of sea urchins increased as the stocking density increased, indicating the existence of adverse social interactions. These adverse social interactions detrimentally affected FW, FTD, SGR, GW and GI (P < 0.01). Although SR decreased with the increasing densities, no statistical significant difference was detected. Sea urchins at D15 had the lowest gonad color difference (ΔE 00) (P < 0.05). However, statistically equal CV of ΔE 00 indicates this density effect was not a result of adverse social interactions. TY and TGY increased with increased density and can be described by the following equations: TY = 84.18X 0.64, R 2 = 0.999 and TGY = 24.16X 0.38, R 2 = 0.979. However, the MY and MGY were not significantly different among stocking densities. The results of this study demonstrate that in intensive culture S. intermedius at low stocking density can achieve high growth rate, gonad index and desirable color without decreasing the marketable yield. Farmers should choose to culture S. intermedius at low stocking densities.  相似文献   

18.
The effects of water velocity and tipping frequency (water movement) on survival, somatic and gonad growth of juvenile and adult green sea urchin, Strongylocentrotus droebachiensis were investigated. Juvenile and adult urchins were held in ‘laminar’ or ‘tipper’ tanks. Both were supplied with three inlet water flows (1.5, 3.0 and 7.5 L min?1) which converted to water velocities of 0.28, 0.57 and 1.43 cm s?1 in the ‘laminar’ tanks and tipping frequencies of 30, 10 and 5 s in the ‘tipper’ tanks. Juvenile sea urchins had significantly lower mortality and greater somatic growth when held in ‘laminar’ flow tanks compared with ‘tipper’ tanks. The varying water velocities tested in the ‘laminar’ flow treatment had no effect on the growth of juvenile sea urchins. The juvenile sea urchins in the ‘tipping’ treatment held at high tipping frequency had significantly slower growth than those in the medium and low tipping frequency treatments. There were no differences in mortality or gonad growth in the adult sea urchins regardless of treatment. The ‘laminar’ flow tanks retained significantly more organic material compared with the ‘tipper’ tanks. The authors discuss the effects of water velocity and tipping frequencies in system design for aquaculture of sea urchins.  相似文献   

19.
During this study different concentrations of magnesium chloride (MgCl2) were tested on adult wild‐caught sea urchins (Paracentrotus lividus) immediately after their collection in the field in order to assess whether MgCl2 can act as an anaesthetic during their transport and prevent unplanned spawning. Such accidental spawning is a stress response associated with transport of this species. The mortality and gonadal indices were recorded after a 1‐h submersion in different strength solutions of MgCl2 (5, 20, 40, 80 and 100 mmol L−1 MgCl2), followed by 5 h of dry transport under two different temperatures (19 and 25 °C). The effective concentration of MgCl2 was defined as one that does not induce mortality and gonad mass loss following sea urchin transport and laboratory conditioning. Treatment of sea urchins with 5 mmol L−1 MgCl2 prevented mortality and unplanned spawning; however, elevated concentrations of magnesium (40, 80 and 100 mM) were toxic to sea urchins, inducing a massive mortality and gonad mass decrease during the acclimatization period, essentially when sea urchins were transported under an elevated temperature (25 °C). It is concluded that MgCl2 is a suitable non‐toxic anaesthetic, easily available for adult sea urchins (P. lividus) when it is used at its optimal anaesthetizing concentration.  相似文献   

20.
Adult green sea urchins Strongylocentrotus droebachiensis were fed three different quantities (0.25, 0.50, 1.00% body weight/d) of a prepared feed during a 12‐wk experiment to determine the effect of food ration on gonad quantity and quality. A diet of kelp, Laminaria longicruris and/or L. digitata, fed at satiation (3% body weight/d) and urchins taken from the wild at the beginning and end of the experiment served as controls. Urchins fed prepared feed or kelp increased their percent gonad yield significantly over the experimental period. Affer 12 wk, individuals fed the prepared diet at 0.50 or 1.00% body weighffd had significantly higher percent gonad yields (mean ± SEM: 23.5 ± 0.6% and 23.4 ± 0.7%, respectively) than urchins fed at 0.25% body weight/d (18.0 ± 1.0%) or control animals given kelp (18.3 ± 0.8%). There was no significant difference in gonad yield between the 0.50 and 1.00% feeding levels. All feeding treatments had significantly higher percent gonad yields than urchins sampled from the wild at the end of the experiment that had recently spawned (2.8 ± 0.5%). There was no significant difference in gonad taste among urchins fed the prepared diet at 0.25% body weight/d, those given kelp, or those collected from the wild at the end of the experiment (good to very good ratings), but all of these treatments had significantly better tasting gonads than urchins given the prepared feed at 0.50 or 1.00% body weight/d (satisfactory ratings). Gonad taste rating of urchins fed a prepared diet was dependent on ration with greater feed amounts leading to worse tasting gonads (linear regression: r2= 0.68, P < 0.01). Gonad color, texture, and firmness did not differ significantly among any of the feed ration treatments or kelp control. Results suggest that the best ration for prepared feed would be 0.50% body weightld since this would optimize gonad yield while minimizing feed costs. Further research on prepared feeds is required to optimize both gonad color and taste.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号