大菱鲆受精卵显微注射技术的建立

本研究将100~300 pg含有肌肉特异表达启动子和绿色荧光蛋白(Green fluorescent protein,GFP)基因的重组质粒(smyd1:gfp)显微注射到大菱鲆(Scophthalmus maximus)受精卵动物极细胞中,通过细心培育,成功孵化出鱼苗约120尾。统计分析显示,显微注射后,大菱鲆胚胎存活率为4.8%。利用荧光显微镜观察大菱鲆胚胎及仔鱼,只在注射smyd1:gfp质粒的胚胎及仔鱼的肌肉中发现有绿色荧光。通过进一步PCR扩增检测,在注射的大菱鲆胚胎及仔鱼DNA中扩增出了GFP特异片段,大小约为340 bp。研究表明,本研究成功建立了大菱鲆显微注射技术,可为大菱鲆基因功能研究和遗传育种奠定基础。     

罗非鱼3个养殖群体的遗传多样性及特异性AFLP标记研究

对不同来源的养殖群体进行种质鉴定,探索在种苗阶段即区分新吉富罗非鱼（New GIFT strain Oreochromis niloticus）、吉诺玛罗非鱼（GenoMar strain O．niloticus）和奥杂罗非鱼（0．niloticus♀×O．aureus♂）3个养殖群体具有重要的意义。笔者选取了5对AFLP（amplified fragment length polymorphism）引物组合对3个罗非鱼养殖群体共60尾个体进行比较分析,引物组合E—ACA／M—CAT表现出较好的区分能力,有7条标记的分布在群体间表现出“有和无”的差别,引物组合E—ACA／M—CAG的扩增图谱中有2条带表现出“有和无”的差别。遗传多样性方面,平均基因多样性在新吉富罗非鱼和吉诺玛罗非鱼分别为0．1605和0．1595,而在奥尼罗非鱼为0．2214,多态位点百分数和Shannnon多样性指数也表现出相近的变化趋势。分析表明新吉富罗非鱼群体在遗传上已较为稳定,吉诺玛罗非鱼遗传多样性偏低。     

Growth studies on juvenile tilapia using pure species, hormone-treated and nine interspecific hybrids

Abstract. The comparative growth performance of the juveniles of six pure tilapia species, Oreochromis mossambicus , O. spilurus , O. macrochir , O. aureus , O. niloticus and Sarotherodon galilaeus were assessed under standardized conditions in a recirculated water system. The effects of standardized treatments of 17α methyltestosterone and 17β estradiol were assessed by comparison with untreated controls of O. niloticus , O. mossambicus and O. aureus and the growth performance of nine interspecific hybrids in comparison to their parental species were studied.
The results showed significant differences in growth rate for the strains of the pure species under the conditions used. Standardized hormone treatment had significant effects on sex ratios and growth performance of all the species studied but did not change their overall performance ranking when compared to the pure species. No hybrid performed significantly better than the best parent for SGR although O. aureus × O. niloticus hybrid was significantly better than O. niloticus when corrected weight gain was used. This work shows that species choice hormone treatment and hybridization have implications for tilapia culture.     

Artificial Spawning of Tilapia Eggs1

A stripspawning methodology was evaluated for tilapia (oreochromid) species. This technique achieved an average hatching success of 68.6 ± 3.6% (N= 31). Female fecundity and spawning frequency were dependant on both genetical and husbandry factors. Egg yields for Oreochromis niloticus, O. mossambicus, and O. niloticus±O. mossambicus hybrids averaged 4.54, 10.86 and 10.36 eggs/g female/spawn, respectively. Female broodstock that were adapted to an intensive spawning regime exhibited a significant increase in fecundity. Additionally, egg survival was not affected by hydration for up to 15 minutes prior to fertilization. Results suggest that the strip spawning of tilapia species may be an efficient method of providing viable gametes for hatchery purposes.     

细胞核rDNA序列用于罗非鱼及其杂交种鉴别的初步研究

罗非鱼种间,尤其是尼罗罗非鱼与杂种尼奥罗非鱼之间,很难区分。本文对尼罗罗非鱼、奥利亚罗非鱼、莫桑比克罗非鱼和杂交种尼奥罗非鱼（尼罗罗非鱼♀×奥利亚罗非鱼♂）和红罗非鱼的核糖体DNA内部转录间隔子1（ITS1）序列及其两侧的18S和5．8s部分序列特征进行分析,以筛选种间鉴别标记。PCR扩增产物大小约700bp,测序结果表明,（去除引物后）18S长146bp,5．8S长66bp,不同种类之间无差异;ITS1长383-483bp,因种类不同而异,其GC含量大于AT含量,达到67．1％。序列比对分析结果表明,18S和5．8s片段高度保守,但各有3个变异位点可以把上述几个种和杂种相互区分开;18S序列上有一个UnbI限制性酶切位点,可作为尼罗和尼奥罗非鱼的鉴别标记。ITS1序列种间变异大,系统发育分析表明,所研究的5个种聚成2个类群,尼罗与尼奥罗非鱼为一组,莫桑比克-红罗非鱼-奥利亚罗非鱼为另一组。组内种间遗传距离较小,尼罗和尼奥罗非鱼的种间遗传距离为0．006;莫桑比克、奥利亚和红罗非鱼的种间遗传距离在0．007-0．009之间;两组罗非鱼之间的遗传距离较大,在0．030-0．035之间,表明罗非鱼ITS1序列多态性较高,适合于种类区分。结合部分18S和5．8S序列,细胞核rDNA具有鉴别罗非鱼及其杂种的潜力。     

尼罗罗非鱼β-actin基因启动子的分离及其在真核细胞中的活性验证

采用高保真PCR方法从尼罗罗非鱼(Oreochromis niloticus)基因组DNA中分离出β-actin基因启动子序列,将β-actin基因启动子插入pN1-EGFP构建成真核细胞表达载体pEGFP-β-actin,并通过脂质体转染法将重组载体导入人胚肾上皮细胞HEK 293T,荧光显微镜下观察外源基因EGFP...     

Digestive capabilities of three commensal fish species: carp, Cyprinus carpio L., tilapia, Oreochromis aureus×O. niloticus, and African catfish, Clarias gariepinus (Burchell 1822)

Abstract. This paper examines the digestibility of different feed mixtures by three species of fish: carp, Cyprinus carpio L., tilapia, Oreochromis aureus × O. niloticus , and African catfish, Clarias gariepinus (Burchell 1822). Protein from poultry sources was digested better by tilapia than by carp or catfish, but no significant difference was found in the case of protein mainly from fish meal. Carp showed the best ability to digest fats, followed by catfish, with tilapia having the least ability. Tilapia digested carbohydrate better than the other two species, however, whether from wheat or corn sources. The same pattern applies to the digestibility of energy.     

罗非鱼性别相关微卫星标记的初步筛选

为分析罗非鱼群体的遗传多样性以及筛选与罗非鱼性别相关的微卫星标记。应用24对微卫星引物,使用常规PCR及聚丙烯酰胺凝胶电泳的方法在两个尼罗罗非鱼(Oreochromis niloticus)群体和两个奥利亚罗非鱼(O.aureus)群体中初步筛选到UNH931、GM128、GM201、GM258、GM597以及UNH898共6个与性别相关的微卫星标记。然后使用降落PCR以及毛细管电泳的方法在两个尼罗罗非鱼群体、两个奥利亚罗非鱼群体以及ZY 1、WY 1、YY 1和YY 2型罗非鱼群体中进一步扩增这6个微卫星标记,统计各群体的遗传多样性参数:6个微卫星标记在上述群体共297个样本中检测到95个等位基因,其大小在97~302 bp之间,各位点在各群体等位基因数在1~13个之间,各群体平均观测等位基因数为2.167~9.333,平均有效等位基因数为1.624~4.966,平均观测杂合度为0.324~0.983,平均期望杂合度为0.329~0.782,平均多态信息含量为0.275~0.753;两个尼罗罗非鱼群体、WY 1和YY 2群体达到高度多态(PIC>0.5),两个奥利亚罗非鱼群体、ZY 1和YY 1群体为中度多态(0.25相似文献   

All-male Tilapia Hybrids of Two Strains of Oreochromis niloticus

Hybridization between Nile tilapia Oreochromis niloticus (Local and Stirling University strains) and blue tilapia O. aureus was found to be a tool to produce monosex populations. In order to select a purebred that produces all- or nearly all-male hybrids with high productivity, O. niloticus females and their diploid gynogenetics (meiogynes and mitogynes) were hybridized with O. aureus males. The sex ratio of progenies was evaluated from inter- and intraspecific crosses of two strains of Nile tilapia. Single-pair matings and group spawns under hatchery conditions showed no deviation ( P > 0.01) from the expected sex ratio of intraspecific crosses among two strains of Nile tilapia. However, a higher proportion of male progenies in blue tilapia was observed in group spawns in pond ( P < 0.004) and hatchery conditions ( P < 0.01). Only the Stirling strain and mitogynes produced all-male progenies under laboratory conditions. There were significant differences ( P < 0.05) in growth among hybrid progeny groups, when gynogens and their regular O. niloticus (Local strain) females were crossed with O. aureus males. Six-month hybrid offspring from mitogyne female parents grew better than those from regular and meiogyne female broods.     

罗非鱼抗逆性研究

研究了奥尼罗非鱼和吉富罗非鱼对低温和重金属的抗逆性。抗冻性实验结果表明,奥尼罗非鱼的抗冻性优于吉富罗非鱼。抗冻性较好的奥尼罗非鱼对重金属的抗逆性研究结果表明,在相同浓度的不同重金属作用下,奥尼罗非鱼幼苗对受试3种重金属离子(Pb2+、Cr6+、Cu2+)的抗逆性均随着作用时间的延长而下降。在相同条件下,对受试3种重金属离子的抗逆性:Cr6+Cu2+Pb2+。     

pH对龟足胚胎和幼虫发育的影响

为探讨水体pH对龟足(Capitulum mitella)胚胎孵化和幼虫生长发育的影响,采用单因子实验的方法,在水温25-28℃条件下,研究了不同pH(5.0,5.5、6.0、6.5、7.0、7.5、8.0、8.5、9.0、9.5)对龟足胚胎的孵化时间、孵化率和幼虫存活率、变态率的影响.结果表明:pH为5.0时,胚胎不...     

四种罗非鱼挥发性成份的GC-MS分析

为了研究四种罗非鱼挥发性成份的化学成分,采用水蒸气蒸馏法提取罗非鱼挥发性成份,用气相色谱-质谱联用仪对其进行分离测定,结合计算机检索对分离的化合物进行结构鉴定,应用色谱峰面积归一化法测定各成分的相对百分含量。结果共鉴定出45种物质:奥利亚和奥尼各26种,尼罗24种,吉富18种。其中,有7种化合物为4种罗非鱼的挥发性成份所共有。2,4-二叔丁基苯酚在挥发性组份中的含量最高(奥利亚38.44%;尼罗37.34%;吉富35.21%;奥尼除外,占14.10%)。在挥发性成份中酯类、醇类、烯烃和有机酸类居多,分别有10种、6种、5种和4种,其中大部分为有特殊香味的挥发性物质,且该类物质在奥利亚、尼罗和奥尼三种罗非鱼中含量较多,在吉富中含量较少。奥尼罗非鱼中还检测出大量的特殊的挥发性物质L-抗坏血酸棕榈酸酯,其含量高达33.64%。     

Growth and Feed Utilization of the Tilapia Hybrid Oreochromis mossambicus×O. niloticus Cultured at Different Salinities under Controlled Laboratory Conditions

Abstract.— Growth and feed utilization of the tilapia hybrid Oreochromis mossainbicus × O. niloticus cultured at different salinities under controlled laboratory conditions were studied for 2 mo. Fish (2.32 g mean initial weight) were grown in 113-L aquaria at salinities of 0.5, 17 and 32 ppt at a density of 20 fish per tank. Mean specific growth, food conversion, and food consumption were determined at each salinity. There was no significant difference ( P > 0.05) in growth among the treatments, although feed conversion and feed consumption were significantly improved (P ≤ 0.05) when fish were grown at 17 and 32 ppt.     

Developmental changes in drinking rate and ion and water permeability during early life stages of euryhaline tilapia, Oreochromis mossambicus, reared in fresh water and seawater

Euryhaline tilapia (Oreochromis mossambicus) can breed either in fresh water (FW) or in seawater, and the developing embryos and larvae withstand direct transfer from FW to SW or vice versa, before the development of osmoregulatory organs. In the study, developmental changes in drinking rate and ion and water permeability were examined after transfer of the embryos from FW to SW. Drinking was measured by accumulation of fluorescent beads in the intestine and also by 14C-dextran accumulation he whole body. The drinking rate increased steadily from 2 to 10 days after hatching, and the larvae in SW consistently imbibed more water than those in FW. The diffusional water permeability remained low during embryonic stages but increased markedly after hatching in both FW and SW; the water permeability was consistently less in SW-adapted embryos and larvae than those in FW. In contrast, the turnover rates of chloride ion in SW were 50 to 100 times greater than those in FW, and increased markedly after hatching. The drinking rate as well as ion and water permeability of the tilapia embryos and larvae in FW and SW were comparable with those reported for stenohaline species. These results clearly indicate that different water and ion regulatory mechanisms are operating in the tilapia embryos and larvae in FW and those in SW to convey their strong euryhalinity.     

Cryoprotectant microinjection toxicity and chilling sensitivity in gilthead seabream (Sparus aurata) embryos

Cryopreservation of fish embryos requires an optimal distribution of cryoprotectants inside all embryo compartments. Traditional techniques for the incorporation of cryoprotectants (CPAs) have failed to protect all fish compartments, especially the yolk sac which has been considered the principal point of embryo chilling sensitivity. In the present study, microinjection was used to incorporate cryoprotectants into the yolk sac of gilthead seabream (Sparus aurata) embryos at tail bud stage. The effect of microinjection viability, cryoprotectant toxicity and chilling resistance was evaluated through the hatching rate. Larval survival at first feeding was also determined in microinjection viability and cryoprotectant toxicity studies. Permeabilized seabream embryos were microinjected with 2.35 nl dimethyl sulfoxide (Me₂SO), methanol (MeOH), ethylene glycol (EG) (5 M, 10 M and pure) or sucrose (10% and 15%). In a second experiment, 29.5 nl and 154.0 nl of the highest concentration of each cryoprotectant were used in the same embryo stage. To test the effect of microinjected cryoprotectants on embryo chilling resistance, 29.5 nl of pure Me₂SO or 15% sucrose was microinjected into the yolk sac of tail bud stage embryos and then at a later stage, (tail-bud-free), were exposed to 3 M Me₂SO solution at − 10 °C for 30 min. Our results showed that microinjection technique did not affect the viability of tail bud stage embryos as is shown by the high hatching and survival rates. Hatching and larval survival rate at first feeding were not affected with any of the CPAs tested, showing percentages higher than 75% and 90%, respectively, when embryos were microinjected with a smaller quantity of cryoprotectant. Sucrose was the cryoprotectant better tolerated at higher concentration and volume. Cryoprotectant concentration inside the yolk higher than 1.18 M for Me₂SO, 1.5 M for EG and 2 M for methanol decreased the hatching rate. Microinjection allowed the delivery of high concentrations of CPAs into the yolk sac without deleterious effects on the embryo, but did not provide a significant level of protection for the whole embryo against chilling injury.     

敌百虫对奥尼罗非鱼幼鱼的急性毒性及安全浓度评价

为研究敌百虫对奥尼罗非鱼幼鱼的急性毒性效应,采用96 h半静水式生物毒性试验方法,在水温(23.5±2.0)℃,溶解氧>5 mg/L的条件下,分别检测在曝气自来水(pH为6.5)和池塘水(pH为8.5)中敌百虫对奥尼罗非鱼幼鱼的急性毒性效应。结果显示:在曝气自来水中,敌百虫对奥尼罗非鱼幼鱼24、48、72、96 h的半致死质量浓度分别为3.68、3.31、2.05、1.57 mg/L,安全质量浓度为0.157 mg/L;在池塘水中,敌百虫对奥尼罗非鱼幼鱼24、48、72、96 h的半致死质量浓度分别为0.35、0.29、0.17、0.13 mg/L,安全质量浓度为0.013 mg/L。试验结果表明,在池塘水中敌百虫对奥尼罗非鱼幼鱼的毒性比在曝气自来水条件下强。     

Screening tilapia for culture in sea water in Kuwait

Abstract. Three experiments were conducted to evaluate the potential for culturing tilapia in tanks and raceways with flowing sea water (39-41 ppt salinity) in Kuwait. In the first and third experiments, fingerling tilapia were grown for 7 to 8 months under ambient conditions. In the second experiment, larger (50-100g initial weight) male tilapia were grown for 6 months. Growth and mortality rates were determined.
Oreochromis aureus (Steindachner) grew the slowest and survived poorly. O. spilurus (Günther) and O. aureus × O. spilurus hybrids had the best survival and moderate growth rates. A red tilapia from Taiwan grew the fastest but had high mortality rates during winter. O. spilurus and the hybrid were best suited for seawater culture under ambient conditions in Kuwait.     

Offspring Growth in a Diallel Crossbreeding with Three Strains of Nile Tilapia Oreochromis niloticus

Abstract— A complete diallel crossing of three strains, Stirling, Korean and Local, was used to evaluate heterosis of intraspecific crossbreeding on early growth of Nile tilapia Oreochromis niloticus . All possible F-1 hybrid offspring were obtained and their growth rates to 90 d were compared. The specific heterosis for F-1 hybrids in Stirling × Korean, Stirling × Local and Korean × Local crosses were 7.61, 5.63 and 7.70 for weight, and 0.47, 0.26 and 0.55 for length, respectively. The purebred Stirling strain showed better growth than the other two strains (P < 0.05). When growth of F-1 hybrids was compared between sexes, males grew more rapidly than females (P < 0.05). However, no differences were observed in growth of male or female between hybrid groups. Purebred males in the Stirling strain were slightly heavier than those in the Korean and Local strains, and Local × Stirling, Korean × Local and Local × Korean crosses. However, in purebred females Stirling was superior to Korean, but not the Local strain and all F-1 hybrid crosses. Implications to choose the appropriate strains for developing a breeding program of tilapia are also discussed.     

Potential of the use of peanut (Arachis hypogaea) leaf meal as a partial replacement for fish meal in diets for Nile tilapia (Oreochromis niloticus L.)

The rapid growth of tilapia culture has stimulated the expansion of tilapia feed production and a search for novel protein sources to replace fish meal. Vegetable or plant sources are promising alternatives and legumes are both naturally abundant and high in protein content. A study was carried out to evaluate the effects of replacing the protein from fish meal with peanut ( Arachis hypogaea ) leaf meal (PLM) in diets for male tilapia ( Oreochromis niloticus , initial body weight 75.3 g). Four isonitrogenous (35% CP) and isocaloric (18.834 kJ g⁻¹) diets were prepared to include 0% (CON), 10% (PLM10), 20% (PLM20) and 30% (PLM30) of PLM protein. Average fish weights at the end of the 126-day experiment were not statistically different among the fish fed CON, PLM10 and PLM20 diets. The PLM30 diet produced the poorest growth performance. Organic matter and protein contents of fish were similar in the CON, PLM10 and PLM20 diets. Carcass chemical composition showed a decrease in body fat content as PLM replacement levels increased. The high survival ratio in all dietary groups (>97%) suggests that PLM can be used in O. niloticus feeds for long periods without affecting fish growth performance or health.     

罗非鱼雌、雄群体遗传差异的RAPD分析

从40个随机引物中分别筛选出15和18个,对奥利亚罗非鱼和尼罗罗非鱼雌、雄群体进行RAPD分析,结果显示:奥利亚罗非鱼雌性群体的多态位点比例为56.25%,基因多样性指数为0.2358,Shannon氏指数为0.3417,群体内的遗传相似指数为0.8625;雄性群体的多态位点比例为57.50%,基因多样性指数为0.2356,Shannon氏指数为0.3418,群体内的遗传相似指数为0.8375。尼罗罗非鱼雌性群体的多态位点比例为47.44%,基因多样性指数为0.1788,Shannon氏指数为0.2637,群体内的遗传相似指数为0.7667;雄性群体的多态位点比例为64.10%,基因多样性指数为0.2347,Shannon氏指数为0.3486,群体内的遗传相似指数为0.6769。试验结果表明,奥利亚罗非鱼雌、雄性群体的遗传多样性程度接近,而尼罗罗非鱼雄性群体的遗传多样性要比雌性群体丰富,遗传变异比雌性群体大。