Comparison of food selection and growth performance of koi carp, Cyprinus carpio L., and goldfish, Carassius auratus (L.) in mono- and polyculture rearing in tropical ponds

To compare the effect of polyculture against conventional monoculture on ornamental carp production, investigations on food selection and growth performance of koi carp (K), Cyprinus carpio L. and goldfish (G), Carassius auratus (L.) were conducted in a 11‐week rearing experiment in two monoculture (100% K and 100% G) and five polyculture (90% K–10% G, 70% K–30% G, 50% K–50% G, 30% K–70% G and 10% K–90% G) conditions in tropical ponds. There were three replicates for each treatment. Environmental conditions and food availability were similar in all the treatments. Ivlev's electivity index showed that both fish species avoided phytoplankton and preferred cladocerans to other zooplankton groups (copepods and rotifers) in monotypic conditions. However, in the polyculture treatments, the positive electivity of goldfish towards cladocerans reduced significantly (P<0.05), while the percentage of copepods, rotifers and phytoplankton in the gut content increased. No significant differences in weight gain, specific growth rate and deformities were recorded at harvest for koi carp between the different treatments (P>0.05). Even the survival rate of koi carp recorded above 90% in all the treatments. However, the goldfish recorded significantly better weight gain, specific growth rate and survival in monoculture (100% G), compared with the polyculture treatments (P<0.05). Goldfish deformities were lowest (P<0.05) in the monoculture treatment (2.42%). The number of marketable fish above a set size limit of 4 g total weight was significantly higher in the two monoculture treatments, compared with the five polyculture treatments (P<0.05). Keeping in view of the dietary similarities of koi carp and goldfish, and the aggressive nature of koi carp in polyculture, it is suggested to refrain from polyculture of goldfish and koi carp until further documentations relating to optimum stocking density and management of polyculture of ornamental carps are available.     

银杏叶提取物对鲫CYP4503A和溶菌酶活性的影响

以红霉素为探针,采用NaSH法研究了银杏叶提取物对鲫细胞色素P4503A和溶菌酶活性的影响.研究结果显示,银杏提取物能诱导鲫细胞色素P4503A活性,试验组CYP4503A活性显著高于对照组,而且银杏叶提取物可以提高鲫头肾溶菌酶的活性和免疫保护率.鲫日粮中添加银杏叶提取物的适宜量为25 mg/kg.     

芙蓉鲤鲫(芙蓉鲤♀×红鲫♂)的性腺组织学及繁殖性能研究

采用解剖观察、组织切片及人工催情等方法,研究芙蓉鲤鲫(Cyprinus capiofurong.♀×Carassius auratus red var.♂)的性腺发育及繁殖性能。结果显示:解剖观察,芙蓉鲤鲫性腺发育异常的个体占83.64%,性腺外观基本正常的个体占16.36%。组织学观察,芙蓉鲤鲫性腺可分三类:两性嵌合体占21.13%,其中以精巢为主的16.90%,以卵巢为主的4.23%,它们性腺发育迟缓,在繁殖季节成熟系数也没有明显变化,性腺多为一侧发育或两侧不对称,两种性腺细胞均不能成熟;雌性个体占40.84%,在生殖季节卵巢可发育到第IV时相,但未见其细胞核发生偏移;雄性个体,占38.03%,在生殖季节只能发育到精子细胞阶段,不能产生成熟的精子。经人工催产,芙蓉鲤鲫少部分个体有发情产卵行为但不能正常受精。结果表明芙蓉鲤鲫为两性败育类型。     

Natural bixin as a potential carotenoid for enhancing pigmentation and colour in goldfish (Carassius auratus)

Discovering natural carotenoids for colour enhancement and health benefits of fish is important to develop new feed formulations. We have purified natural bixin from achiote seeds and evaluated the effect of colour enhancing and pigmentation in goldfish. Varying levels of bixin‐based diets were prepared with 420 g kg^?1 of crude protein and 120 g kg^?1 of lipid content. Our results clearly showed that bixin (0.05, 0.10, 0.20 and 0.60 g kg^?1) based diets significantly (P < 0.05) enhanced the skin and fin colour at 30 and 60 days compared to diet without bixin. Interestingly, diet which contains 0.20 g kg^?1 bixin and commercial feed (with astaxanthin) had similar effect on carotenoid deposition in skin. Moreover, total carotenoid deposition in fin was higher than in skin of all bixin‐containing diets. However, 0.60 g kg^?1 bixin‐containing diet had lower specific growth rate (1.01 ± 0.01) and higher feed conversion ratio (2.05 ± 0.19) compared to the control group. The present results demonstrate that achiote bixin can be successfully used as an alternative natural carotenoid source against synthetic astaxanthin in fish feed. Our data indicate that 0.20 g kg^?1 is a suitable dietary level of bixin to ensure strong pigmentation, acceptable growth and feed utilization in goldfish.     

鸡枞菌多糖对鲫的生长性能、抗氧化及免疫功能的影响

为了探讨鸡枞菌多糖(TAP)对鲫(Carassius auratus)的生物学活性,以饲料里添加1%的黄芪多糖(APS)为对照,连续14 d在鲫饲料里分别添加0.1%、0.5%和1%的TAP,观察其在第7和14天对鲫肥满度、肝体比、头肾体比、肝胰脏中MDA、CAT、SOD以及LZM的影响。结果显示:实验第7天,TAP高剂量组的肥满度极显著高于其余各组,其余各组在实验期间的肥满度与肝体比均无显著差异。与空白组比,实验第7天,APS组与TAP中剂量组的肝胰脏MDA含量分别极显著和显著降低;在给药期间两种多糖均使CAT和SOD水平有不同程度的升高。与空白组比,给药期间,TAP和APS均能不同程度提高鲫头肾体比,且二者差异不显著;TAP高剂量组的LZM水平显著提高,且显著高于APS组。结果表明,TAP对鲫连续给药14 d的促生长作用不显著,但可通过上调CAT、SOD来降低MDA,且对非特异性免疫功能有显著提高。     

Comparative study on dietary protein requirements for juvenile and pre‐adult gibel carp (Carassius auratus gibelio var. CAS III)

Two 8‐week growth trials were conducted in indoor recirculation system to evaluate the protein requirements for juvenile (3.70 ± 0.20 g) and pre‐adult (85.2 ± 0.70 g) gibel carp, Carassius auratus gibelio var. CAS III. Six isoenergetic diets were formulated for each trial using fish meal and casein as protein sources, and protein level was 250–450 g kg^?1 in Trial 1 and 200–450 g kg^?1 in Trial 2. With the increasing dietary protein, feeding rate (FR) and feed conversion ratio (FCR) significantly decreased (P < 0.05). Weight gain (WG) increased first and then reached a plateau in 330–450 g kg^?1 in Trial 1 (P > 0.05), while decreased after the maximum value in 350 g kg^?1 in Trial 2 (P < 0.05). Productive protein values (PPVs) were lower in 370–450 g kg^?1 in Trial 1 and 400–450 g kg^?1 in Trial 2 (P < 0.05). Increasing dietary protein level increased protein content and decreased lipid content in whole fish body and white muscle (P < 0.05). Apparent digestibility coefficient of dry matters (ADC_d) decreased, while apparent digestibility coefficient of protein (ADC_p) increased in 370–450 g kg^?1 in Trial 1 and 250–450 g kg^?1 in Trial 2 (P < 0.05). Trypsin activity significantly increased in 370–450 g kg^?1 in Trial 1 (P < 0.05) and was not affected in Trial 2 (P > 0.05). Hepatic alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in both trials increased when dietary protein was above 400 g kg^?1 (P < 0.05). Based on quadratic regression of WG, it was estimated that dietary protein requirement for maximum growth was 414 g kg^?1 (digestible protein of 376 g kg^?1) and 365 g kg^?1 (digestible protein of 324 g kg^?1) for juvenile (3.70 g) and pre‐adult gibel carp (85.2 g).     

17β—雌二醇对雄性金鱼卵黄原蛋白的诱导作用

采用腹腔注射17β-雌二醇的方法诱导雄性金鱼卵黄原蛋白产生,注射浓度为0.05mg·g-1BW,诱导2周后取尾静脉血,离心分离血浆,进行血浆常规聚丙烯酰胺凝胶电泳,通过对卵黄原蛋白特性基团磷、脂和糖蛋白的染色,确定了卵黄原蛋白在电泳图谱上的位置,开发了一种简便、高效的定性卵黄原蛋白的聚丙烯酰胺凝胶电泳法。电泳结果表明,在0.05mg·g-1BW的注射浓度下,2周后17β-雌二醇诱导了雄性金鱼卵黄原蛋白产生,并通过ELISA检测卵黄原蛋白的平均含量为690.2ng·mL-1,与对照组雄性金鱼平均含量为10.7ng·mL-1的差异极显著(P<0.01),比雌性对照组检出量285.5ng·mL-1高1倍多;17β-雌二醇诱导组雄鱼血浆钙离子和血总蛋白含量明显增加。     

SOST基因在淇河鲫肌间骨骨化过程中的表达研究

为探索硬化蛋白(sclerostin,SOST)基因在淇河鲫肌间骨骨化过程中的调控作用,本研究以淇河鲫仔稚鱼为研究对象,利用整体骨骼染色法对肌间骨的形态发生进行观察,并采用q RT-PCR、Western Blot和免疫组织化学技术检测SOST基因在肌间骨不同骨化阶段的m RNA和蛋白表达变化情况。结果显示,淇河鲫发育至24 dpf(day post fertilization),肌膈中出现纤维束;25 dpf髓弓小骨出现,28 dpf脉弓小骨出现,33 dpf髓弓小骨出现分叉,45 dpf肌间小骨发育完全。SOST基因在肌间骨骨化发生各阶段均有表达,23 dpf的表达量最低(P0.05),随着肌间小骨的骨化发育,SOST基因呈递增趋势,45 dpf表达量显著高于其他骨化阶段(P0.05);SOST蛋白在45 dpf时显著高于23和27 dpf(P0.05),与其他发育阶段无显著差异(P0.05)。SOST m RNA和蛋白变化趋势基本相同,都在23dpf处于最低,肌间骨全部出现后表达量达到最高,与淇河鲫肌间骨的形态发生趋势一致。因此,推测SOST与淇河鲫肌间骨骨化具有一定的相关性,可调控肌间骨的分化和形成。     

Effects of glycinin on growth performance,immunity and antioxidant capacity in juvenile golden crucian carp,Cyprinus carpio × Carassius auratus

This study was designed to examine the effects of glycinin on growth, digestive ability, immune responses, antioxidant capacity and gene expression levels of golden crucian carp. Golden crucian carp were fed diets containing glycinin at 0, 30, 60, 90 and 120 g/kg, respectively, for 8 weeks. Body weight, weight gain percentage, specific growth rate and feed efficiency ratio were negatively related to the content of glycinin in diet. Activities of protease, acid phosphatase, alkaline phosphatase, lysozyme in hepatopancreas, and activities of catalase, glutathione peroxidase, superoxide dismutase, and total antioxidant capacity in the proximal intestine, mid intestine, distal intestine and hepatopancreas were negatively related to the content of glycinin in diet, whereas malondialdehyde in proximal intestine, mid intestine, distal intestine and hepatopancreas increased directly with the content of glycinin in diet. Furthermore, the relative expressions of TNF‐α and IL‐1β in proximal intestine, mid intestine and distal intestine increased directly with the content of glycinin in diet, whereas the relative expressions of TNF‐α and IL‐1β in hepatopancreas were negatively related to the content of glycinin in diets. The relative expressions of IL‐10 in proximal intestine, mid intestine, distal intestine and hepatopancreas all were negatively related to the content of glycinin in diets. In conclusion, reductions in growth, immunity and antioxidant capacity, intestine inflammation with dysfunction of digestive system occurred in golden crucian carp that fed a diet containing glycinin at 30 g/kg or higher after 8 weeks.     

异育银鲫“中科三号”对盐度和碳酸盐碱度的耐受性

研究了盐度和碳酸盐碱度对不同规格异育银鲫(Carassius auratus gibelio)"中科三号"鱼种的急性和慢性毒性。结果表明,异育银鲫"中科三号"大规格鱼种[L=(8.81±0.62)cm]48、72 h和96 h的盐度半致死浓度分别为15.433、14.352、13.855,盐度安全浓度为4.63;碳酸盐碱度在24、48、72、96 h的半致死浓度分别为73.105、71.861、71.198、70.368 mmol·L-1,碳酸盐碱度的安全浓度为20.33 mmol·L-1。小规格鱼种[L=(1.78±0.12)cm]24、48、72 h和96 h盐度的半致死浓度分别为11.339、11.026、10.653、10.080,盐度安全浓度为2.98;碳酸盐碱度的半致死浓度分别为52.656、51.889、50.378、49.664 mmol·L-1,碳酸盐碱度的安全浓度为13.20 mmol·L-1。大规格"中科三号"鱼种对盐度和碳酸盐碱度的耐受性均比小规格鱼种强;慢性毒性实验中异育银鲫"中科三号"鱼种[L=(3.73±0.12)cm]的特定生长率和相对增重率均随着盐碱浓度的增大而降低。60 d实验后盐度3、5和7组的特定生长率分别为1.14、0.67和0.23,相对增重率分别为98.64、49.24和14.80;碳酸盐碱度7、12和17 mmol·L-1组的特定生长率分别为1.12、0.66和0.29,相对增重率分别为96.06、48.40和19.23。盐度和碳酸盐碱度浓度越强,对异育银鲫"中科三号"鱼种生长的影响越大。