诺氟沙星在草鱼体内的残留规律研究

研究了多剂量混饲口灌给药方式下,诺氟沙星在草鱼体内的残留消除情况。结果显示：以每千克鱼体重10 mg连续5d混饲给药后,停药后第12天在草鱼肌肉中未检测到药物,此时血清、肝脏和肾脏中的药物浓度分别降为（0.0287±0.0015）μg/mL、（0.0181±0.0042）μg/g和（0.0369±0.0037）μg/g,均低于0.05μg/mL或0.05μg/g。因此初步建议在（19±1）℃水温条件下,以每千克鱼体重10 mg连续5 d混饲给草鱼诺氟沙星,休药期至少为最后一次给药后的12 d。     

A review of spawning induction,larviculture, and juvenile rearing of the fat snook, <Emphasis Type="Italic">Centropomus parallelus</Emphasis>

The fat snook, Centropomus parallelus, is a commercially valuable marine fish species with potential for aquaculture. This paper describes the development of technology for mass production of fat snook juveniles at the Experimental Fish Hatchery of the Universidade Federal de Santa Catarina, focusing on research about reproduction, larviculture, and juvenile rearing. Induced spawning of wild fat snook was first achieved in 1991 with a single injection of human chorionic gonadotropin (hCG). There was a substantial increase in egg quality when broodstock was conditioned in maturation rooms and induced to spawn. Different dosages of luteinizing hormone-releasing hormone analogue (LHRHa) with saline injection and colesterol implant were also tested. As fat snook exhibits group-synchronous oocyte development, females could be induced to spawn (with 35–50 μg kg⁻¹ of LHRHa) once a month, resulting in up to four consecutive spawnings. Results of larval culture were highly variable at the beginning; survival rates were frequently around 1% until the juvenile stage. Several experiments were conducted to evaluate the effect of environmental factors and feeding quality on survival and growth. With the improvement of the spawning induction technique and better larviculture practices, survival rates increased to 10–30%. Studies on the particular requirements of juveniles in terms of stocking density, feeding, nutrition, and environmental factors were also performed in order to improve growth rates and feed utilization. The present study demonstrates the feasibility of mass production of fat snook juveniles. However, further research is needed to develop cost-effective grow-out technology.     

A comparison of the growth and survival of two freshwater crayfish species, Astacus leptodactylus Eschscholtz and Pacifastacus leniusculus (Dana), under different temperature and density regimes

Growth experiments carried out with two juvenile crayfish species, Astacus leptodactylus Eschscholtz and Pacifastacus leniusculus (Dana), at different temperatures and densities highlighted the problem of cannibalism under conditions aimed at intensifying crayfish production. Cannibalism proved to be much lower in A. leptodactylus than P. leniusculus, suggesting that the former might be the better candidate for astaciculture. In the first of two population survival trials, A. leptodactylus showed a higher survival rate than P. leniusculus, with 26% of P. leniusculus surviving in the first replicate, compared to 42.3% of P. leniusculus, and 40.76% surviving in the second replicate, compared to 47.6% of P. leniusculus. The same trend was observed in the second experiment, with P. leniusculus showing survival rates of 48.5 and 55.3% (first and second replicates, respectively) in comparison to 65.2 and 68.2%, respectively, for A. leptodactylus. It is therefore highly likely that if P. leniusculus were to become established in Turkey, it would outcompete the native A. leptodactylus even if it were not to be devastated by the crayfish plague that has decimated the native species. The experiments also highlighted the problem of differential growth, with some juveniles hardly growing at all while others reached a relatively large size. The range in carapace length (CL) was 9–18 mm for A. leptodactylus and 8.5–18.5 mm CL for P. leniusculus at the end of the first experiment. While both species grew quickly, P. leniusculus hatched earlier, giving it an advantage over A. leptodactylus; consequently, by the end of the summer, the juveniles of the former were larger than those of A. leptodactylus. Specific growth rate values showed that the juveniles of the two species had similar growth rates. The results also revealed that growth was not significantly affected by density in both species at 15°C, but at 25°C, growth was significantly better at a density of 234 juveniles m⁻² than at 468 juveniles m⁻², and better at 468 juveniles m⁻² than at 937 juveniles m⁻² (P < 0.01 and P < 0.001, respectively). We conclude that P. leniusculus is a good candidate for aquaculture as it has a rapid growth rate and early hatching and maturity; however, its aggressive behavior may make it a less attractive proposition than A. leptodactylus, which is also fast growing but less aggressive. This study is a part of PhD study of M.M. Harlıoğlu, who is supported by Fırat University Elazığ, Turkey.     

Improving initial survival in cultured seahorses, Hippocampus abdominalis Leeson, 1827 (Teleostei: Syngnathidae)

This investigation aimed at improving early juvenile survival in cultured seahorses, Hippocampus abdominalis. Phototaxis from birth until 2 months of age was tested and juveniles were found to be positively phototactic within this age range. A comparison of the effect of culture vessel background (white vs. black vs. clear jars) on feeding efficiency at 1 week and 1 month of age using Artemia as prey revealed an age-dependent effect upon both attack rate and capture success. At 1 week, both attack rate and capture success were higher for juveniles contained in clear jars, and capture success was higher in black jars, as compared with white jars. At 1 month, there was no significant difference in attack rate between different jars, although capture success was higher in clear and white jars than in black jars. In a top-illuminated glass aquarium, juveniles with access to the water surface had lower survival (mean±1 SE=50±4.5%) than those without access to the water surface (73.3±4.2%). This was due to the ingestion of air bubbles when preying on Artemia nauplii congregating near the water surface. For side-illumination there was no such difference. Glass aquaria that were side-illuminated and blacked-off upwards from the waterline supported high juvenile survival (80.4±4.0% per brood) from birth through to 2 months of age in four broods.     

草鱼干扰素的分离纯化及某些理化和生物学特性

通过ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ阴离子交换层析、Ｓｅｐｈａｃｒｙｌ Ｓ－２００凝胶层析、高效液相层析和梯度聚丙烯酰张胶电泳等技术，对病毒诱生的草鱼血清干扰素进行了分离纯化。纯化的草鱼干扰素在ＳＤＳ－聚丙烯酰胺凝胶电泳中呈现单一组份，分子量为３８ｋＤ，等电点为５．２５，过碘酸－Ｓｃｈｉｆｆ试剂反应表现为典型的糖蛋白染色特征。理化和生物学特性研究表明，草鱼干扰素具有１０００００ｇ（２ｈ）离心不沉降、耐     

The risk of parasite transfer to juvenile fishes by live copepod food with the example Triaenophorus crassus and Triaenophorus nodulosus

Natural zooplankton is a potential food resource for juvenile fish in fish farms as it is a good source of fats, carbohydrates, and protein. However, it is also a potential source of parasites and pathogens. The present study was conducted (1) to estimate the risk of parasite transfer by live copepod food under intensive farming conditions using the parasites Triaenophorus crassus and Triaenophorus nodulosus as example and (2) to look for strategies to avoid parasite infestation of juvenile fish.An easy and routinely applicable aniline blue staining method was developed to check the infestation levels of copepods with procercoids during the on-growing season of juvenile fish. From the copepod species occurring in zooplankton Cyclops spp. was infested frequently (9.4 ± 12.0%, maximum 38.7%), Diaptomus spp. infrequently (1.5 ± 1.6%, maximum 3.2%), Daphnia spp. never. Juvenile grayling, Thymallus thymallus, and corgonids, Coregonus sp., which had been fed with natural zooplankton revealed infestations rates with T. crassus of circa 5%, with T. nodulosus of circa 10%. As the occurrence of procercoids in the zooplankton was temporary limited, Triaenophorus infestation can be avoided by using artificial food instead of live copepods during the risky season.To prevent parasite infestation of juvenile fish methods were investigated to eradicate procercoids from copepods by chemical treatment (sodium chloride, hydrogen peroxide, citric acid treatment) and by freeze-thawing methods. Chemical methods failed to remove procercoids. In fish, which had been fed with frozen thawed zooplankton, no Triaenophorus spp. infestation was observed. Their survival rates were similar as in the control fed with live zooplankton, however the weight of the fish was significantly lower.     

饲料中添加不同水平的维生素D_3对草鱼幼鱼生长和体成分的影响

本文以酪蛋白和脱脂豆粕为蛋白源,糊精为糖源,玉米油和豆油为脂肪源的半纯化饲料为基础饲料,研究维生素D3对草鱼(Ctenopharyngodon idellus)幼鱼生长及体成分的影响。维生素D3共设0,100,200,500,1000,2000,3000 IU/kg 7个添加梯度,每一梯度设3个重复,每个重复放养60尾初始体质量(3.86±0.34)g的草鱼,在(26.9±3)℃的流水系统中养殖8周。结果显示:维生素D3对草鱼幼鱼增重率、特定生长率、饲料系数、存活率、体水分、粗蛋白质、粗脂肪含量和血清钙浓度没有显著性影响(P>0.05);对照组和添加100 IU/kg维生素D3的试验组中,草鱼幼鱼的粗灰分显著低于其它试验组(P<0.05);与对照组相比,饲料中添加维生素D3对全鱼钙磷含量、血清磷离子浓度以及碱性磷酸酶活性影响显著(P<0.05)。根据维生素D3对全鱼钙磷含量的影响,草鱼幼鱼饲料中维生素D3适宜的添加量为1000 IU/kg。     

草鱼HSP70基因cDNA部分序列克隆及其组织表达差异

根据鲤热休克蛋白70(Heat shock protein,HSP70)序列(AY120894)设计并合成一对引物,以草鱼(Cteno-pharyngodon idella)肝胰脏组织总RNA为模板,RT-PCR扩增获得草鱼HSP70基因cDNA部分序列,并进行了组织表达差异性研究。结果显示:所获为序列为480 bp,获得GeneBank登陆号为FJ483832。序列测序结果显示,HSP70扩增序列与鲤、斑马鱼、鲋的同源性为:93%、91%、93%。另外,所获序列HSP70在草鱼脂肪、肌肉、肠、脑、粘液、性腺、鳔、肝胰脏、心脏、脾脏、鳃、鳍12个组织的表达存在差异,HSP70在草鱼这12个组织中均检测到表达,其中在鳍中表达最高,极显著高于其他组织(P<0.01);在鳔中表达次之,且与脑、心脏、性腺中表达差异不显著;在粘液中表达最低。     

草鱼LPL基因的表达及饥饿和再投喂对其影响

获得了草鱼脂蛋白脂酶(lipoprotein lipase, LPL)部分cDNA序列（GenBank注册号为FJ612596），并进行了序列同源性分析；采用半定量反转录聚合酶链式反应（SQ-RT-PCR）方法，检测了LPL基因在草鱼不同组织和不同发育阶段脂肪细胞中的表达状况；研究了饥饿和再投喂对草鱼肝胰脏LPL基因表达的影响。结果显示，所获得的草鱼LPL部分cDNA序列长度为360 bp，与其它物种的同源性为70%~89%； LPL基因在肝胰脏、肌肉、心脏、鳃、腹腔脂肪组织中均表达，其中在腹腔脂肪组织中表达丰度最高，在鳃中表达丰度最低；在成熟脂肪细胞中的表达丰度显著高于基质脉管组分（stromal vascular fraction,SVF）细胞；草鱼LPL基因表达水平在饥饿48 h后显著升高，再次投喂后12 h，回复到0 h的表达水平。研究表明，草鱼LPL在不同组织及脂肪细胞分化的起始和终末阶段均有表达，显示其在草鱼不同组织和脂肪细胞分化中具有重要作用，同时，其表达水平受营养状况的调控。论文首次克隆得到草鱼LPL基因部分cDNA序列，并对其进行了表达分析，研究结果可为LPL在鱼类脂质代谢中的作用研究提供参考和依据。