棉酚对尼罗罗非鱼（Oreochromis niloticus）生殖机能影响的研究

用含０．１％乙酸棉酚的饲料饲养二月龄尼罗罗非鱼稚鱼四个月，其增重和血浆睾酮水平与对照鱼无显著差异，并且同时开始发情，交配和产卵，生殖腺发育正常，仅血浆皮质醇水平略高于对照组，实验结果表明，棉籽饼（粉）内含的棉酚浓度（０．０３－０．０５％），不会影响尼罗罗非鱼的性腺正常发育和生殖机能，肌肉中棉酚残留量为１０．３ｐｐｍ，远低于食用油的允许量（２００ｐｐｍ）。     

棉酚对金鱼、罗非鱼的毒性作用初探

用乙酸棉酚含量为１‰的鱼粉饲料分别饲喂性成熟的金鱼和二月龄尼罗罗非鱼。四个月后，试验组金鱼、罗非鱼与对照组鱼在体重增长、饲料效率、特定生长率、性腺重及性重比（性腺重／鱼体重）方面的差异不明显，表明饲料中棉籽饼水平的棉酚含量（０．０３％～０．０５％），既不影响这两种鱼的正常摄食和生长，也不影响其正常的性成熟和繁殖。     

棉酚对罗非鱼、鲤和金鱼血钾及肝肾器官的影响

棉酚对罗非鱼、鲤和金鱼血钾及肝肾器官的影响富惠光，卢彤岩，叶继丹，张良（黑龙江水产研究所，哈尔滨１５００７０）关键词棉酚，淡水鱼，血钾，病理组织ＥＦＦＥＣＴＯＦＧＯＳＳＹＰＯＬＯＮＬＩＶＥＲ，ＫＩＤＮＥＹＡＮＤＰＬＡＳＭＡＰＯＴＡＳＳＩＵＭＬＥＶＥＬ...     

棉酚对鲤鱼急性中毒的研究

鲤鱼（体重约16克）腹腔注射乙酸棉酚0，7．3，54，100，200，400mg/kg体重，经四天（96小时）后，死亡率分别是0，0，20％，70％，90％，100％。96小时半数致死剂量是63．6mg/kg体重。注射剂量高于54mg/kg体重时，发生腹腔红肿、体壁溃烂，甚至死亡。实验结果说明虽然棉籽水平的棉酚不引起鲤鱼的任何可见的中毒症状，但是腹腔注射大剂量棉酚可引起与哺乳类相似的中毒症状。     

四种罗非鱼精子超微结构的比较

借助扫描电镜和透射电镜对尼罗罗非鱼(Oreochromis niloticus)、奥利亚罗非鱼(O.aureus)、奥尼罗非鱼(O.niloticus×O.aureus)和吉富罗非鱼(GIFT Strain in Nile Tilapia,O.niloticus)成熟精子的超微结构进行了比较研究。结果显示,4种罗非鱼精子均为有鞭毛精子,无顶体,尾部轴丝9+2型。尼罗罗非鱼精子植入窝陷入核深度最浅,线粒体个数和平均直径分别为5~9个、(0.36±0.10)μm,鞭毛侧鳍平均翼长为(0.29±0.11)μm;奥利亚罗非鱼精子核内染色质着色程度最深,植入窝陷入核深度约1/3,线粒体个数和平均直径分别为3~10个、(0.40±0.17)μm,鞭毛侧鳍平均翼长为(0.32±0.12)μm;奥尼罗非鱼精子核内染色质着色程度较浅,植入窝陷入核深度约1/3,线粒体个数和平均直径分别为5~7个、(0.32±0.09)μm,鞭毛侧鳍平均翼长(0.26±0.09)μm;吉富罗非鱼精子核内染色质着色最浅,植入窝陷入核最深,约占2/3,线粒体个数和平均直径分别为5~10个、(0.37±0.08)μm,中段存在大量中空囊泡,鞭毛侧鳍平均翼长为(0.15±0.03)μm,与其它三种罗非鱼精子鞭毛平均侧鳍翼长比较具显著性差异(P0.05)。     

“桂非1号”罗非鱼在老挝示范养殖试验

在老挝万象开展"桂非1号"罗非鱼养殖示范试验,在当地气候、水温等自然生态情况下,研究了"桂非1号"罗非鱼苗种培育存活率、成鱼养殖的存活率及池塘产量等,提出了"桂非1号"罗非鱼良种在当地高产稳产养殖的主要技术措施。     

BALB/c小鼠用于评价尼罗罗非鱼无乳链球菌毒力的研究

实验采用BALB/c小鼠作为实验动物,旨在建立尼罗罗非鱼无乳链球菌毒力测定的BALB/c小鼠模型。BALB/c小鼠经腹腔注射尼罗罗非鱼源无乳链球菌建立感染模型,比较了尼罗罗非鱼源无乳链球菌分别感染尼罗罗非鱼和小鼠的LD_(50)差异,分别测定了不同毒力尼罗罗非鱼无乳链球菌对尼罗罗非鱼和小鼠的毒力。结果显示,小鼠经腹腔注射无乳链球菌,在24 h内出现死亡现象,且对小鼠脑、肝脏、脾脏、肾脏等组织造成损伤。3次测定尼罗罗非鱼无乳链球菌TFJ0901对尼罗罗非鱼和小鼠LD_(50)分别为7.7×10~7、2.2×10~8、3.5×10~9 CFU/mL和405、361、419 CFU/只。将无乳链球菌TFJ0901和THN0901感染尼罗罗非鱼(1.0×10~7 CFU/mL)和小鼠(100 CFU/只),尼罗罗非鱼和小鼠存活率分别为100%、6.7%±5.8%和100%、0,其存活率都具有显著性差异。将无乳链球菌TFJ0901和TFJ-F感染尼罗罗非鱼(3.0×10~8 CFU/mL)和小鼠(2 500 CFU/只),尼罗罗非鱼的存活率分别为73.3%±11.5%和80.0%±10.0%,存活率差异不显著,小鼠存活率分别为13.3%±11.5%和100.0%,存活率具有显著性差异。研究表明,本实验成功建立了BALB/c小鼠作为尼罗罗非鱼源无乳链球菌毒力测定的稳定模型,测定不同毒力的尼罗罗非鱼源无乳链球菌对小鼠毒力与对尼罗罗非鱼毒力一致,且该模型能够区分尼罗罗非鱼模型难以区分的毒力相近的无乳链球菌。     

猪棉酚中毒的诊断和预防措施

棉酚又名棉毒素或棉籽醇，是棉属植物内形成的一种黄色的酚型物质。棉粕中的有毒成份有游离棉酚、棉酚紫和棉绿素3种色素，其毒性以棉绿素最强，游离棉酚次之。但游离棉酚的含量远比另2种色素高，因此棉粕的毒性决定于游离棉酚的含量。棉粕含粗蛋白36％-44％，粗纤维11％-15％，此外B族维生素、硫胺素和磷含量十分丰富，是一种很好的蛋白质饲料。我区是棉花主产区，棉粕产量很大，各猪场时常发生棉酚中毒，现就棉酚的毒性、危害、防治方法介绍如下：     

罗非鱼、南美白对虾体内药残状况研究

以广东省养殖罗非鱼及南美白对虾为实验对象,就其体内土霉素等多种渔药残留及分布状况进行研究, 比较不同规格罗非鱼及南美白对虾体内渔药残留差异,分析渔药在罗非鱼及南美白对虾不同部位的残留状况。结果表明在罗非鱼体内已烯雌酚、呋喃唑酮、氯霉素3种渔药未见检出,南美白对虾体内已烯雌酚、呋喃唑酮、氯霉素、(口恶)喹酸和喹乙醇5种渔药均未见检出,而土霉素等常规用药在罗非鱼和南美白对虾体内均有不同程度的检出。渔药残留量因其规格大小及部位而异,趋势为大规格样品渔药残留量相对较高,在罗非鱼及南美白对虾体内的增长情况与其体重具有负相关性;罗非鱼内脏渔药残留量明显高于肌肉组织,虾头为虾渔药残留的主要场所。     

棉酚毒性研究的回顾

棉酚是存在于棉属植物中的一种黄色多酚型毒素.就棉酚对人类、畜禽以及水产动物的毒性进行了概述,着重阐述了棉酚对鱼类的毒性及棉籽饼粕饲料在水产养殖中的利用问题.     

Long-term effects of the cryopreservation of turbot (Psetta maxima) spermatozoa

The survival of turbot eggs and the rearing capacities of larvae stemmed from artificial fertilization practices using frozen-thawed spermatozoa were evaluated. Furthermore, the viability of sperm samples stored during a 9 month period in liquid nitrogen was assessed. No significant difference in the fertilization rate, hatching rate, survival and wet weight of 10-day old larvae were observed using fresh or frozen-thawed spermatozoa. The motility recorded at 10 s and 60 s post-activation and the fertilization capacity of frozen-thawed spermatozoa were not significantly decreased during a 9 month storage period in liquid nitrogen. These results confirm the high quality of the turbot spermatozoa stemmed from the cryopreservation process, allowing their use for routine aquaculture practices.     

日本蟳精子超低温冷冻保存技术的研究

以精子存活率作为评价指标,采用两步降温法研究了稀释剂、抗冻保护剂和预冷时间对日本蟳精子超低温冷冻保存效果的影响。结果表明:以采用稀释剂II、15%二甲基亚砜(DMSO)作为抗冻保护剂的保存效果最佳。在液氮中保存24 h后,精子存活率可达83.76%,保存一年后可达73.81%。精液的第一次预冷时间以25 min为宜。     

金乌贼纳精囊组织结构及其精子的储存和利用

为揭示金乌贼精子进入纳精囊及产卵过程中的精子利用方式,丰富金乌贼繁殖生物学研究内容,本研究利用实验生态学和组织切片技术,检测了交配后不同时间段雌性口膜表面精子囊和纳精囊中精子数量的变化,观察分析了雌性金乌贼纳精囊的组织结构。结果显示,金乌贼纳精囊位于繁殖期雌性个体口膜腹面的突起处,共1对。纳精囊开口于口膜内表面,通过一根中央管连通整个纳精囊。中央管内壁含有大量褶皱和纤毛。在中央管两端,有12~20个储精小囊与之相连。储精小囊四周具有发达的环肌,其中储存有大量精子,并且大部分精子头部均朝向腔室内壁。完成一次交配后,雌性金乌贼对精子囊和纳精囊中精子的利用可以分为三个阶段,主要利用精子囊中的精子(交配后1~2 d);由利用精子囊中的精子向纳精囊中的精子过渡(交配后2~3 d);主要利用纳精囊中的精子(交配后3 d以上)。研究表明,从精子囊释放出的精子进入雌性口膜表面的褶皱中,通过自身运动到达纳精囊。进入纳精囊的精子通过自身运动及中央管内壁纤毛的摆动进入储精小囊,其中大部分精子头部朝向储精小囊内壁有规律地分布。在产卵过程中,雌性优先利用精子囊中的精子,而在精子囊中精子不足时,纳精囊通过肌肉收缩以及纤毛摆动将其中的精子逐渐释放出来,卵子在雌性口膜附近完成体外受精。     

Cryogenic and Refrigerated Storage of Rainbow Smelt Osmerus mordax Spermatozoa

The effects of extender composition, cryoprotectant, and freezing rate on post-thaw rainbow smelt Osmerus mordax sperm motility were examined, and the fertilization capacity of fresh and post-thaw sperm were compared. The highest post-thaw motility (75%) was obtained when milt was diluted 1:3 with an extender containing 600 mM sucrose supplemented with 10% dimethyl sulfoxide and 1.5% bovine serum albumin and frozen at a rate of –20 C/min. Post-thaw motility for sperm stored in this extender was similar to fresh sperm and did not change after 90 d of storage. Furthermore, there were no differences in fertilization rate or embryo survival to the eyed stage between fresh and post-thaw sperm frozen in this extender. The lowest post-thaw motility was observed when sperm were frozen with methanol at a rate of -30 C/min. Refrigerated sperm diluted 1:3 with the 600 mM sucrose extender remained motile for 30 d. These data demonstrate that rainbow smelt spermatozoa can be effectively used following short and long-term storage using a simple, sucrose-based extender.     

Cryopreservation of sperm from spotted wolffish

The effects of different concentrations of cryoprotectant (dimethyl sulfoxide; DMSO), cooling rate and straw size on the post-thaw motility of frozen sperm from spotted wolffish, Anarhichas minor, were studied. There was no significant difference in the post-thaw motility of sperm treated with three different concentrations of DMSO (10, 20 and 30%). Similarly, there was no significant difference in the post-thaw motility of spermatozoa when using different freezing rates (i.e. distance of straws from the surface of liquid N₂, 4.7, 5.5 and 7.1°C min⁻¹) and the straw size (0.5 and 1.0 ml) did not affect survival. The cryopreservation of sperm can be used to make up for the frequent lack of sperm and/or the unsynchronised timing of sperm production in spotted wolffish males and the ovulation time in females. The results show that sperm from spotted wolffish can be frozen to secure access to viable sperm, but further experiments are needed in order to reveal the effect of different parameters on the post-thawing mortality and define the optimum conditions for cryopreservation.     

Effects of Cryopreservation on Morphology and Viability of Sperm and Larvae of Atlantic Cod,Gadus morhua L.

The effects of cryopreservation on the viability, morphology and capability of spermatozoa in Atlantic cod, Gadus morhua L., were studied. The sperm was cryopreserved in straws using Hanks' balanced salt solution, hens' egg yolks and glycerol in the vapor of liquid nitrogen. Straws of cryopreserved sperm were stored in liquid nitrogen and thawed in seawater (35 C) for 8 sec before use. The motility of cryopreserved sperm was low (range 8–19%) compared to motility before freezing (range 69–76%). The fertilization rate (range 94–95%) in control groups using fresh sperm was significantly higher (P < 0.05) than in test groups (range 48–72%). In cryopreserved sperm, a relatively high percentage (range 82–93%) of the spermatozoa had changes in morphology. Many spermatozoa had no mitochondria; when mitochondria were present, the observed number varied from one and five in cryopreserved spermatozoa, and from two and seven in noncryopreserved spermatozoa. In groups where cryopreserved sperm was used, the hatching rate was lower (range 18–38%) than in control groups (range 41–63%), indicating higher mortality during embryonic development. Paternal effects on progeny performance were noted in the proportion of abnormalities but no negative effects were identified in newly hatched larvae produced using cryopreserved sperm.     

鲤、鲢、鳙精子低温短期保存研究

本文对鲤(Cygrinus carpio)、鲢(Hypophthalmichthys molitrix)和鳙(Aristichthys nobilis)精液在2—4℃的短期保存进行了实验研究。筛选出了几种较为理想的稀释保护液配方;确定了精液与稀释液的适宜稀释比例为1:1;研究了抗冻剂二甲亚砜(DMSO)对低温保存条件下精于活力的影响,确定了DMSO的适宜添加浓度为6％左右。鲤精在2—4℃保存10天,活力仍高达70％,少数精子存活时间长达12天;鲢和鳙精子在2—4℃保存7天后活力仍高达60％,达到了生产应用的水平。为水产养殖和鱼类育种研究提供了一种简便易行的精液短期保存技术。     

Production of androgenetic amago salmon<Emphasis Type="Italic"> Oncorhynchus masou ishikawae</Emphasis> with dispermy fertilization

With the aim of improving artificial androgenesis in teleost fishes, we tested two methods for producing androgenetic diploids of amago salmon (Oncorhynchus masou ishikawae), namely, fertilization of gamma-ray irradiated eggs with fused spermatozoa (sperm-fusion method) and the fertilization of irradiated eggs with untreated sperm followed by the blocking of cell division (mitosis-inhibition method). Our results showed that the optimal condition for sperm fusion was to treat the sperm with 50% polyethylene glycol (molecular weight 7500) for 100 s. The efficiency of the two methods of androgenesis was compared in terms of fertilization rate, hatching rate, and larval survival after hatching. The rate of fertilization was lower with the sperm-fusion method than with the mitosis-inhibition method, but the reverse was true for the hatching rate. The survival rate of hatched larvae was the same with the two methods. Androgenesis was confirmed with a recessive albino color marker, and all viable offspring were found to be heterozygous based on analysis of the microsatellite markers. Our results suggest that androgenesis with the sperm-fusion method is a promising approach with potential applications in both aquaculture breeding programs and the preservation of endangered freshwater fishes.     

Fertilization efficiency of cryopreserved sperm from striped catfish, Pangasius hypophthalmus (Sauvage)

The fertilization efficiency of cryopreserved sperm was compared with fresh sperm from striped catfish, Pangasius hypophthalmus . Of the two sets of experiments carried out, the first compared four sperm doses using fresh sperm and fresh eggs. The second experiment compared six concentrations of cryopreserved sperm ranging from 6.94 × 10⁷ to 6.94 × 10¹⁰ to fertilize 100 eggs per batch. Fertilization, hatch and survival rates were compared between cryopreserved and fresh sperm. The highest fertilization rate (53.75±1.62%) was achieved with a sperm dose of 6.94 × 10⁸. Increasing the sperm dose to 3.47 × 10⁹ did not increase the fertilization rate, indicating that the optimum sperm:egg ratio lies between 6.94 × 10⁶ and 3.47 × 10⁷ sperm per egg. Both highest (6.94 × 10¹⁰) and the lowest (6.94 × 10⁷) sperm doses resulted in lower fertilization rates (2.04% and 16.90% respectively). No significant differences were found among four fresh sperm doses compared. Mean hatch and survival rates resulting from fresh and cryopreserved sperm were similar. The experiment shows that while only 1.89 × 10⁶ fresh spermatozoa was required to fertilize a fresh egg, 6.94 × 10⁶ (or 3.67 times more) cryopreserved sperm was required to achieve the same level of fertilization. This provides important information for making decision to cryopreserve sperm for commercial and/or conservation purposes.     

Influence of photoperiod, frequency of stripping and presence of females on sperm output in turbot, Scophthalmus maximus (L.)

Abstract. The effect of four environmental conditions was investigated upon sperm output in turbot, Scophthalmus maximus (L.), submitted to three different rhythms of stripping. Males kept under a natural light cycle and under a 6-month contracted light programme released a similar sperm output in terms of total volume of semen produced per fish during the experimental period (4·9 ± 0·9ml), mean sperm concentration (29·4 ± 2·8 × 10⁹ spermatozoa/ml) and total sperm number (163·2 ± 40·5 × 10⁹ spermatozoa). Attempts to stimulate spermiation for a second time just after the end of the natural reproduction period resulted in the release of low sperm output (total volume of semen: 1·6 ± 0·4 ml; mean sperm motility: 2 min 36s ± 0 min 47s; mean sperm concentration: 47·6 ± 10·2 × 10⁹ spermatozoa/ml; total sperm number: 84·5 ± 25·3 × 10⁹ spermatozoa). Stripping frequency had no effect on total volume of semen, mean sperm motility and total sperm number. Monthly collection did not modify sperm samples in relation to stripping rank. However, decreasing volume, motility and sperm concentration were observed when males were stripped fortnightly and weekly. During the natural spawning period, the presence of females in the tank enhanced mean sperm motility (from 3 min 27s + 0 min 52s to 6 min 38s ± 1 min 38s).