乌苏里拟鲿(Pseudobagrus ussuriensis)同工酶分析

采用聚丙烯酰胺凝胶电泳方法,对黑龙江水系乌苏里拟鲿(Pseudobagrus ussuriensis)心、肝、肾、眼、肌肉和性腺共6种组织进行了9种同工酶(ADH、EST、G6PDH、GDH、IDH、LDH、MDH、POD、SOD)的分析。结果表明,乌苏里拟鲿EST、GDH、IDH、POD同工酶谱中存在不同程度的组织特异性,EST表现出明显的性别差异性。共记录19个基因位点,多态位点百分数P=21.05%,种群遗传偏离指数d=-1,该乌苏里拟鲿种群内部杂合子缺失较严重,偏离Hardy-Weinberg平衡,遗传多样性较低。     

联肼·乙螨唑对蔬菜优势叶螨产卵发育的影响及其田间防效

为明确新型复配杀螨剂联肼·乙螨唑对目前蔬菜田常发生的2种优势叶螨二斑叶螨Tetranychus urticae和截形叶螨T. truncatus的杀螨活性,于室内采用离体叶碟法测定其对这2种叶螨产卵及发育的影响,于室外采用活体植株评价该药剂对2种叶螨的田间防效。结果表明,经复配杀螨剂联肼·乙螨唑及其单剂处理2种叶螨雌成螨24 h后,死亡率为20.50%～54.98%,均显著高于清水对照;联肼·乙螨唑处理较清水对照显著降低了2种叶螨卵发育至若螨期的比率,联肼·乙螨唑处理后二斑叶螨和截形叶螨的若螨率分别为4.91%和1.63%。田间试验中联肼·乙螨唑对2种叶螨具有一定的速效性,药后3 d对二斑叶螨和截形叶螨的防效分别达95.74%和89.83%,药后7 d防效分别为98.03%和99.44%,显示了优良的防控效果及持效性。表明复配杀螨剂联肼·乙螨唑可用于田间蔬菜优势叶螨种群的高效防控。     

Apparent digestibility coefficients of animal and plant feed ingredients for juvenile Pseudobagrus ussuriensis

A study was conducted to determine apparent digestibility coefficients (ADCs) of dry matter (DM), crude protein (CP), lipid, gross energy, phosphorus and amino acids (AAs) from Peruvian fish meal (PFM), native fish meal (NFM), meat bone meal (MBM), dried daphnia meal (DDM), soybean meal (SBM), full‐fat soybean (FSBM), cottonseed meals (CSM), rapeseed meal (RSM) and corn gluten meal (CGM) for Pseudobagrus ussuriensis (7.8 ± 0.06 g). Test diets were formulated to contain a 70:30 mixture of reference diet to test ingredient with chromic oxide (5 g kg^–1) serving as the inert marker. ADCs of DM ranged from 49.94% (CGM) to 87.11% (PFM), the highest ADCs of DM were observed in PFM and the lowest was found in CGM. ADCs of CP in the test ingredients ranged from 74.92% (CGM) to 93.41% (SBM). ADCs of crude lipid ranged from 51.80% (CGM) to 94.07% (PFM) for fish. ADCs of energy ranged from 56.42% (CGM) to 90.09% (PFM). ADCs of phosphorus ranged from 21.81% (CSM) to 65.70% (PFM). AA availability for the test ingredients followed a similar pattern to ADCs of CP, in which values for PFM, NFM and MBM were generally higher (p < .05) than those of other protein ingredients. Among all plant meals, the AA availability values in SBM were higher (p < .05) than those in CGM, CSM and RSM. The availability of most AAs in CGM was the lowest (p < .05) among all tested ingredients. In conclusion, PFM and NFM are good sources of available protein and AAs. When fishmeal supply is limited, MBM and DDM are substitutes for fishmeal reduction in P. ussuriensis diets; at the same time, SBM and FSBM are also very acceptable protein feedstuffs. However, CSM, RSM and CGM could not be used at high levels in P. ussuriensis diets because of their inferior digestibilities.     

江黄颡鱼人工繁殖的初步研究

对江黄颡鱼（Pseudobagrus uachelli Richardson)的人工繁殖进行了初步试验，先用LRH-A2预备针催熟，再用1mgPG 2.5mgDOM 3.5μgLRH-A2混合催产，水温24-27℃下，效应时间为20-24h，产卵率可达97%，采用等渗液稀释磨碎的精巢，经人工授精，受精率达70%，采用塑料网片粘卵，在卵化环道内孵化，孵化率达94%，此外，对江黄颡自然繁殖的生态条件进行了探讨。     

野生乌鳢、鲶、黄颡鱼和黄鳝的脂类及脂肪酸组成比较

对4种野生鱼黄鳝、鲶、黄颡鱼和乌鳢肝脏和肌肉中的脂类及脂肪酸组成进行了研究。结果表明，黄颡鱼肌肉和肝脏中的总脂含量均高于其它3种鱼，鲶肌肉的中性脂含量最小，极性脂含量最大；在4种鱼的脂肪酸组成中，肝脏的单不饱和脂肪酸、多不饱和脂肪酸含量大于肌肉。4种鱼肌肉脂肪酸组成中，n-3与n-6系列脂肪酸之比差异较大，而肝脏中的n-3与n-6系列脂肪酸之比为0．84左右，没有显著差异。4种鱼中，黄鳝除肝脏饱和脂肪酸含量小于乌鳢外，其肌肉饱和脂肪酸、单不饱和脂肪酸含量及肝脏单不饱和脂肪酸含量均大于其它3种鱼，而多不饱和脂肪酸含量则较其它3种鱼小。与其它食品比较，4种鱼均含有较高的多不饱和脂肪酸，以及较大的C20：5n-3和C22：6n-3含量。     

江黄颡(♀)和乌苏里拟鲿(♂)及其杂交子代遗传变异的RAPD分析

利用RAPD分子标记分析了江黄颡(♀)和乌苏里拟鲿(♂)及其杂交子代3个群体的遗传结构。18个RAPD随机引物对每个群体8尾鱼的基因组DNA进行扩增,共获得106个条带清晰且重复性较好的RAPD标记,片段大小在200~2 000 bp之间,江黄颡(♀)和乌苏里拟鲿(♂)及其杂交子代3个群体的多态位点比例分别为17.92%、18.87%和25.47%,平均遗传相似系数分别为0.940 8、0.936 8和0.928 0,平均遗传距离分别为0.059 2、0.063 2和0.072 0,平均Nei’s基因多样性指数(H)分别为0.075 4、0.073 8和0.103 6,平均Shannon信息指数(I)分别为0.108 7、0.108 1和0.150 1;亲缘关系树状图显示杂交子代与母本遗传距离较近,而与父本遗传距离较远。结果分析表明:杂交子代继承了双亲的优良性状,但从母本中继承的遗传物质稍多于父本;杂交子代群体内的遗传多样性高于两亲本群体,杂交一代基因杂合性增强,表现出一定的杂种优势。     

温度对截形叶螨生长发育和繁殖的影响

在室内15—35℃恒温条件下,截形叶螨的发育历期与温度呈负相关,在15、25和35℃下雌螨一代平均历期分别为32.13、9.02和5.64天;雌、雄螨一代发育起点温度分别为10.90和11.33℃,有效积温分别为135.42和110.47日度;不同温度对世代存活率及子代雌雄性比的影响无显著差异,但雌成螨的寿命及产卵期均随着温度的升高而缩短;30℃下内禀增长率(0.3298)、周限增长率(1.3907)、净增殖率(130.993)、日产卵量(10.98)及总产卵量(181.90)都最高,30℃是种群繁殖增长的最适温度。     

江黄颡鱼适宜生长水温的研究

将江黄颡鱼放在5组不同水温(20℃、23℃、26℃、29℃、32℃),体积为100 cm×40cm×50 cm的水族箱中饲养45 d,每组设三个重复.试验结果表明在20～29℃下,鱼体的绝对增重率和相对增重率随着水温的升高而增大,但到32℃时增重率有所下降;江黄颡鱼生长的适温范围为23～32℃,最适水温为29℃±1℃.     

Influence of enteric helminths on the distribution of intestinal endocrine cells belonging to the diffuse endocrine system in brown trout,Salmo trutta L

The presence of intestinal helminths in the alimentary canal of brown trout, Salmo trutta L., can alter the number of cells that synthesize modulatory peptides. A total of 167 brown trout were collected from tributaries of the River Brenta (northern Italy), of which 119 (71.3%) specimens were infected with enteric helminths, 28 with the acanthocephalan Pomphorhynchus laevis Müller, 1776 with intensity of infection ranging from 1 to 162 (18.57 +/- 30.79) worms per host and 67 fish with the cestode Cyathocephalus truncatus Pallas, 1781. Intensity of infection with C. truncatus ranged from 1 to 85 (6.87 +/- 12.59) per fish. In 24 fish there were concurrent infections of both species of helminths. The caecal and middle regions of the intestine were the most heavily parasitized. Immunohistochemical tests showed a decrease in endocrine cells (ECs) of the diffuse endocrine system (DES) positive to gastrin, cholecystokinin-8, bombesin and secretin antisera in the intestine of the infected trout. The number of ECs immunoreactive to anti-glucagon serum did not show differences in the digestive tract of uninfected brown trout and in conspecifics parasitized with P. laevis. The density of cells containing glucagon-like material was low in the fish parasitized with C. truncatus. The results suggest that endoparasitic helminths induce alterations in the DES of infected S. trutta.     

黄颡鱼人工繁殖及鱼苗培育试验

以鲜鱼虾肉、自制配合料为饵料，在室内和室外水泥池内进行黄颡鱼亲鱼培育；采用DOM、PG、LHRH－A2、HCG不同剂量组合进行人工催产；采用静水和微流水两种方法进行孵化。在孵化网箱内进行鱼苗培育。结果表明：黄颡鱼亲鱼喜食新鲜饵料，也易驯食配合饲料，室内和室外人工条件下均能获得成熟亲鱼；用DOM＋HGG＋LHRH－A2或PG＋HCG＋LHRH－A2的混合剂人工催产，微流水孵化效果较好，催产率为50％－1005，受精率为60％－90％，孵化率达70％－90％；小网箱培育鱼苗，成活率高，规格整齐。