橙色莫桑比克罗非鱼（Oreochromis mossambicus）和荷那龙罗非鱼（O．hornorum）的选育效果评价

以橙色莫桑比克罗非鱼（Oreochromis mossambicus）和荷那龙罗非鱼（O．hornorum）为基础群体，分别对其进行选育，并对产生的选育系F4代的选育效果进行了评价。经过4代的选育，橙色莫桑比克罗非鱼和荷那龙罗非鱼的日增重率分别比对照系提高了27．96％和36．73％，差异显著（P〈0．05），平均每代选育效应分别为6．99％和9．18％。F4代的体重变异系数分别为23．74％和22．17％，比对照组分别降低了24．83％和36．33％。而且第一次性成熟时这2种罗非鱼的平均体重都比对照系增加2倍以上，其杂交子代的雄性率达到了99．4％。试验结果表明，橙色莫桑比克罗非鱼和荷那龙罗非鱼的选育效果明显，F4代的生长性能有了显著提高，个体之间的生长速度趋于一致；也说明这2种罗非鱼F4代仍具有一定的选育潜力，对其继续进行选育是切实可行的。     

中华乌塘鳢耗氧率和窒息点的研究

对两种规格中华乌塘鳢的窒息点和在不同水温条件下的耗氧率进行了测定。结果表明,水温和体重对中华乌塘鳢的耗氧率有显著影响。水温从16℃上升到32℃,大规格鱼（平均体重40.2g）的耗氧率从37.34mg/kg·h增加到136.72mg/kg·h;小规格鱼（平均体重18.0g）的耗氧率从42.81mg/kg·h增加到203.62mg/kg·h。水温与耗氧率的关系可用幂函数表示。水温25℃时,大小两种规格中华乌塘鳢的窒息点分别为0.2744mg/L和0.3031mg/L。     

5种杂交F_1罗非鱼生长性能比较研究

对4种杂交F1尼奥罗非鱼(不同尼罗罗非鱼品系♀×奥利亚罗非鱼♂)尼奥Ⅰ、尼奥Ⅱ、尼奥Ⅲ、尼奥Ⅳ与莫荷鱼(莫桑比克罗非鱼♀×荷那龙罗非鱼♂)进行了生长对比试验。试验结果表明:①绝对增重率(g/d)为莫荷鱼>尼奥Ⅱ>尼奥Ⅲ>尼奥Ⅰ>尼奥Ⅳ(P<0.01);②五种杂交F1罗非鱼雄性率为莫荷鱼>尼奥Ⅲ>尼奥Ⅰ>尼奥Ⅱ>尼奥Ⅳ(P<0.05),成活率彼此间无差异(P>0.05);③肥满度(K)为莫荷鱼>尼奥Ⅰ>尼奥Ⅲ>尼奥Ⅱ>尼奥Ⅳ(P<0.01)。以上结果表明,莫荷鱼生长性能较好,具有推广的价值。     

丁鱥耗氧率和窒息点的初步研究

实验温度(26.1±0.5)℃,试验鱼平均体长10.60 cm,平均体质量13.09 g。丁鱥耗氧率为0.0849mg/(kg.h),窒息点为0.7598 mg/L。丁鱥的耗氧率呈明显的昼夜变化,白天平均耗氧率为0.0585 mg/(kg.h),夜间平均耗氧率为1.1161 mg/(kg.h)。丁鱥的耗氧量随着体重的增加而增加,耗氧率随着体重的增长而减小。在一定水温范围内,耗氧率随着水温的上升而增大。     

梭鲈夏花鱼种耗氧率和窒息点的研究

对体长2.94~3.43 cm、体重0.215~0.237 g的梭鲈夏花鱼种,测定在不同水温条件下的窒息点、昼夜耗氧率、耗氧量。结果表明:梭鲈夏花鱼种的平均窒息点为1.5137 mg/L;其耗氧率呈现明显的昼夜变化,平均耗氧率为0.644 mg/g.h,耗氧高峰出现在夜间;水温对梭鲈窒息点及耗氧率均有显著的影响。     

中华倒刺鲤鱼种耗氧率和窒息点的初步研究

在一定水温条件下,对中华倒刺鲃鱼种(1.55～7.28 g)进行了耗氧率和窒息点的测定,结果表明:耗氧率随鱼体体重的增加而降低.平均体长4.35 cm,均重1.55 g的个体,平均耗氧率为0.4202mg/g·h,窒息点为0.4412 mg/L,平均体长7.22 cm,均重7.28 g的个体,平均耗氧率为0.2222 mg/g·h,窒息点为0.8831 mg/L.水温与耗氧率呈正相关.     

莫桑比克罗非鱼和荷那龙罗非鱼耐盐性的初步研究

用人工配制的6个盐度咸水(0、15、25、30、35、40),对莫桑比克罗非鱼和荷那龙罗非鱼耐盐性进行了初步研究。结果表明:在几种耐盐指标中,莫桑比克罗非鱼和荷那龙罗非鱼的96小时半致死盐度分别为22．29和21．56;在除盐度为40外的其它各盐度梯度中,莫桑比克罗非鱼的50％成活时间和平均成活时间均高于荷那龙罗非鱼,但差异不显著 (p>0．01)。在对2种罗非鱼的盐度驯化过程中,各个驯化盐度梯度下,莫桑比克罗非鱼的死亡率均小于荷那龙罗非鱼的死亡率。     

斑鳠鱼种耗氧率和窒息点的测定

在水温24.4-26.0℃时对斑Hui鱼种（尾重1.12-4.61g）进行了耗氧率与窒息点测定。结果表明：耗氧率与窒息点均随鱼体体重的增加而降低。平均尾重4.61g的斑Hui耗氧率为0.1580mg/g.h，窒息点为0.1292mg/L；平均尾重1.12g的斑Hui氧率为0.2636mg/g.h。窒息点为0.3040mg/L。白昼和夜晚耗氧率的差异不大。     

中华倒刺鲃鱼种耗氧率和窒息点的初步研究

在一定水温条件下 ,对中华倒刺鱼种 (1 5 5～ 7 2 8g)进行了耗氧率和窒息点的测定 ,结果表明 :耗氧率随鱼体体重的增加而降低。平均体长 4 35cm ,均重 1 5 5 g的个体 ,平均耗氧率为 0 42 0 2mg/g·h ,窒息点为0 441 2mg/L ,平均体长 7 2 2cm ,均重 7 2 8g的个体 ,平均耗氧率为 0 2 2 2 2mg/g·h ,窒息点为 0 8831mg/L。水温与耗氧率呈正相关。     

军曹鱼幼鱼耗氧率与窒息点的研究

对平均体质量为16.0g～18.4g的军曹鱼在不同水温和盐度条件下的耗氧率进行了测定。结果表明,水温对军曹鱼的耗氧率有显著影响。盐度29‰时,水温从17℃上升到32℃,军曹鱼的耗氧率从0.357mg/g·h增加到0.880mg/g·h,水温(X)与耗氧率(Y)的关系可用幂函数表示:Y=0.0045X1.5197。在水温29℃时,军曹鱼的耗氧率随着盐度的变化而变化。此外,军曹鱼的耗氧率表现出较明显的昼夜变化规律,在中午前和傍晚后较高。水温对军曹鱼幼鱼的窒息点有显著影响。水温从21℃升高到33℃,窒息点从0.74mg/L增加到1.44mg/L。盐度对窒息点的影响不显著。     

Effect of hybridization on reproductive performance of Oreochromis karongae,Oreochromis shiranus and Oreochromis mossambicus

The study assessed the effect of hybridization on reproductive performance of Oreochromis karongae, Oreochromis shiranus and Oreochromis mossambicus for a period of 120 days. Number of eggs per batch, number of females spawned, relative fecundity, egg size, hatching period, hatchability and hatchling survival were assessed. The results revealed higher number of eggs per batch and relative fecundity in the crosses where O. shiranus and O. mossambicus were females than female O. karongae. The results also revealed that egg size, hatching period, hatchability and hatchling survival were species specific. Significant differences were noted for number of eggs and larvae produced by the three species (p < .05). Interspecific and pure crosses for the same female species did not differ significantly for the number of eggs per batch, relative fecundity, egg size, hatching period, hatchability and hatchling survival. However, number of female spawned was found to be higher in the interspecific crosses of female O. karongae than in pure cross of O. karongae. Findings from this study suggest that hybridization can be used to improve reproductive performance of O. karongae as the females spawned increased, and it is a value addition in aquaculture management of indigenous species.     

罗非鱼养殖技术之一大水面网箱养殖奥尼罗非鱼技术

大水面是渔业生产重要的水资源,发展大水面渔业具有广阔的前景。为此,作者于2005年在24万亩的东江湖水面中开展了网箱养殖奥尼罗非鱼试验,获得成功并取得了很好的效果和效益。一、大水面养殖条件 1．地理位置东江湖位于郴州市所辖的资兴市境内,耒水上游,于 1986年关闸蓄水,集雨面积4719km2,正常水位24万亩,库容81亿方,为湖泊与山谷型兼容的大型水库。 2．地形地貌东江湖周围的资兴市境内以山地为主,东南高,西北低,土壤以红、黄土壤为主,丘陵、岗地、平地交错。其中,平     

不同品系尼罗罗非鱼致死低温的研究

在室内自然降温条件下，研究了三个品系尼罗罗非鱼（吉富品系，“７８”品系，“８８”品系）对低温的耐受力，计算得出每个品系的半致死低温，并对降温过程中尼罗罗非鱼行为活动的变化进行了观察。试验结果表明，在上海地区，当温度降低到１１℃时，罗非鱼开始死亡，到７．４℃时，全部死亡。吉富罗非鱼死亡温度范围是１１℃￣８．４℃，“７８”品系是９．８￣７．４℃，“８８”品系是１１℃￣７．４℃。对三个品系半致死低温的研     

罗非鱼养殖技术之三奥尼罗非鱼与淡水白鲳池塘混养技术

奥尼罗非鱼是雄性奥利亚罗非鱼和雌性尼罗罗非鱼杂交仔一代,具有适应性广、雄性率高、食性杂、饲料利用率高、抗病力强、群体生长快、产量高等优点,是一个优质高产的好品种,适合在各种水面进行养殖.淡水白鲳学名为短盖巨脂鲤,属脂鲤目、脂鲤科、巨脂鲤属,是热带和亚热带食用与观赏兼备的大型经济鱼类,具有体型大、生长快、食性广、病害少、耐低溶解氧、易起捕、好垂钓等优点,己成为池塘养殖的当家品种.     

尼罗与奥利亚罗非鱼对池塘蓝藻水华及水质影响的研究

利用尼罗罗非鱼和奥利亚罗非鱼进行了池塘抑藻试验,采用血球计数板测定水体中的微囊藻密度,并对水体理化性质进行了检测分析。试验结果表明,罗非鱼能有效消减水体中蓝藻生物量,降低水体藻毒素浓度,并对水体TN、TP产生一定影响。其中奥利亚罗非鱼试验组蓝藻初始密度为1．53-108cells／L,下降至0．86-108eells／L,降低43．79％;尼罗罗非鱼组蓝藻初始密度为1．54-108cells／L,下降至O．51×108cells,L,降低66．88％。水体总磷含量无显著变化,总氮含量有所下降,水体微囊藻毒素MC—LR含量随着蓝藻密度的下降而降低,并讨论了尼罗与奥利亚罗非鱼摄食抑制蓝藻的摄食抑制及其对水质的影响。     

Effects of Thermal and Thermo-Haline Shocks on Survival and Osmotic Concentration of the Tilapias Oreochromis mossambicus and Oreochromis aureus × Oreochromis niloticus Hybrids

Abstract.— The effects of thermal and thermo/haline shocks on the tilapias Oreochromis mossambicus and O. aureus × O. niloricus hybrids were investigated. Fingerlings were transferred abruptly from 25 C fresh water to fresh water or salt water (26 ppt) maintaining temperatures of 15, 20, 30 and 35 C. In fresh water, fish survival was not affected by temperature shock, but they suffered from a chill coma and developed fungal infection at 15 C. In salt water, thermo-haline shock did not affect the survival of O. mossambicus , while the survival rates of tilapia hybrids were 6.7, 100, 100, 70 and 59.7% at 15, 20, 25, 30 and 35 C, respectively. Plasma osmotic concentrations of O. mossambicus transferred to 15 and 35 C salt water were quickly and sharply increased, but gradually decreased to lower levels. Osmotic concentrations of tilapia hybrids were also increased, but never returned to their initial (lower) levels over one week. This study revealed that these fishes are more tolerant to high rather than low temperature shocks and O. mossambicus are more resistant to thermo-haline shocks rather than tilapia hybrids. It also indicated that thermo-haline shocks should be minimized during fish transportation and acclimation.     

Juvenile tilapia (Oreochromis niloticus×Oreochromis aureus) requires dietary myo-inositol for maximal growth

An 8-week growth experiment was conducted to estimate the dietary requirement of myo-inositol (MI) for juvenile hybrid tilapia. MI was supplemented at 0, 150, 250, 350, 450, 600, and 1200 mg/kg diet in the basal diet providing 0, 167, 259, 367, 479, 612, and 1253 mg MI/kg diet. Basal diet without MI but with succinylsulfathiazole to suppress MI synthesis by intestinal bacteria was included for comparison. Each diet was fed to triplicate groups of tilapia (mean initial weight 0.51±0.01 g, n=3). Fish fed ≥367 mg MI/kg diet had significantly (P<0.05) higher weight gain, followed by fish fed 259 mg MI/kg diet, and lowest for fish fed the unsupplemented basal diet. Fish fed ≥367 mg MI/kg diet had higher feed efficiency than fish fed the basal diet. Supplementation of dietary inositol did not affect survival of tilapia. The MI concentrations in liver were highest in fish fed the ≥479 mg MI/kg diet, followed by fish fed the 259 and 167 mg MI/kg diets, and lowest in fish fed the basal diet. Hepatic lipid concentrations were higher in fish fed 367 mg MI/kg diet than fish fed ≤259 mg MI/kg diet. Weight gain percentage and MI concentrations in the liver for the different treatments were analyzed by broken-line regression and indicated that the requirement for dietary MI in growing tilapia is about 400 mg/kg diet. Addition of an antibiotic to basal diet did not affect the growth and hepatic inositol concentration of tilapia, suggesting that the intestinal microbial synthesis was not a significant source of inositol for tilapia.     

奥利亚罗非鱼性别人工控制实验

奥利亚罗非鱼(Oreochromis aurea)的性别机制为WZ♀-ZZ♂类型,为探讨WZ♀-ZZ♂型鱼类性别人工控制的途径,进行了性激素诱导实验。实验表明:采用剂量为100 mg/kg的雄性激素处理性腺未分化的鱼苗(全长8～10 mm),可使WZ型合子鱼苗转化为生理雄鱼(WZ△♂);采用雌性激素处理,能使ZZ型合子转化为生理雌鱼(ZZ△♀);采用二系配套法(ZZ△♀×ZZ♂),可使原系ZZ型雄鱼100%恢复。     

奥利亚罗非鱼DMO cDNA的分离和克隆

采用RTPCR和RACE法分离和测定了奥利亚罗非鱼DMOcDNA的全序列。得到1571bp[不含poly(A)]的全长cDNA,包括148bp5’非翻译区,1230bp阅读框以及含Poly(A)信号AATAAA的193bp3’非翻译区[不包括Poly(A)]。阅读框共编码409氨基酸,与尼罗罗非鱼DMO编码的氨基酸序列进行比较,同源性为96.3%,表明DMO在同一物种中差别较小。而与尼罗罗非鱼,红鳍东方豚,虹鳟,青鱼将,鼠,人等动物的DMRT1编码的氨基酸序列进行比较,同源性分别为:25.7%,25.8%,24.3%,29.7%,22.5%,22.0%,这说明DMO和DMRT1可能是两个不同的基因。