呼玛河3种茴鱼遗传分化及属内地位的微卫星分析

茴鱼属（Thymallus）是黑龙江水系特有的珍稀濒危冷水性鱼类,本研究利用6对微卫星引物,对采自黑龙江上游呼玛河同域分布的黑龙江茴鱼（T.grubii）、下游黑龙江茴鱼（T.tugarinae）及待定名种（T.sp.）3种茴鱼的遗传多样性进行了比较研究,以探讨其种群遗传结构、分化水平及分类学地位,为制定保护管理策略提供遗传学理论依据。结果显示,黑龙江茴鱼、下游黑龙江茴鱼和待定名种的平均等位基因数（Na）分别为17.3、18.2和15.3,平均杂合度（H）分别为0.9112、0.9190、0.8492,多态信息含量（PIC）为分别为0.8900、0.8980和0.8250,种群中的特有等位基因数分别为34、37和43。黑龙江茴鱼与下游黑龙江茴鱼的遗传距离（Ds）最小（0.9617）,下游黑龙江茴鱼与待定名种最大（1.8427）,3种茴鱼的Fst为0.1575（P〈0.01）,远大于黑龙江茴鱼、下游黑龙江茴鱼的不同地理种群间的遗传分化水平。研究表明,黑龙江上游3种茴鱼具有很高的遗传多样性水平,3个种间产生显著的遗传分化,结合3种茴鱼种间稳定而显著的形态学特征差异及其地理分布现状,支持黑龙江上游呼玛河同域分布的3种茴鱼在属内各为独立种的分类学地位。     

黑龙江上游3种茴鱼分类地位的线粒体D-loop序列变异分析

基于茴鱼属(Thymallus)鱼类的线粒体D-loop片段全序列变异,对分布于黑龙江上游中国境内的呼玛河、额木尔河等水系中形态特征差异显著且同域分布的3种茴鱼共24个个体进行分子系统发育关系研究,以探讨其在属内的分类学地位.结果显示,分布于黑龙江上游的茴鱼群体在属内显著分为3个独立进化分支,平均序列分歧为0.048～0.062,已达到种间分化水平.经形态学鉴定,其中2个分支分别为黑龙江茴鱼(T.grubii)和下游黑龙江茴鱼(T.tugarinae),而另外1个分支应为1个新种;且该种与分布于勒拿河上游的勒拿河茴鱼((T.sp.)构成单系群,平均序列分歧仅为0.006,即黑龙江上游和勒拿河上游的待定名茴鱼为同一种,结合文献,该茴鱼被确定为北极茴鱼(T.arcticus)的1个亚种.综合3种茴鱼在黑龙江水系的地理分布现状,对其起源及演化进行了初步推测.     

05下游黑龙江茴鱼种群遗传变异及地理分化的微卫星分析

下游黑龙江茴鱼(Thymallus tugarinae)为黑龙江水系中国境内茴鱼属(Thymallus)新纪录种,也是黑龙江水系特有的珍稀濒危冷水性鱼类.本研究利用7对微卫星引物,对乌苏里江(WS)、黑龙江上游的呼玛河(HM)和额木尔河(EM)3个下游黑龙江茴鱼地理种群的遗传多样性进行了比较研究,以探讨其种群遗传结构及地理分化水平,并为制定保护管理策略提供遗传学依据.结果显示,WS、HM和EM种群的平均等位基因数(Na)分别为18.1、14.4,和11.7,平均杂合度(H)分别为0.816 5、0.807 2和0.818 4,多态信息含量(PIC)分别为0.891 3、0.805 3和0.757 7,种群中的特有等位基因数分别为33、16和7.遗传多样性水平以WS最高,HM次之,EM最低,在地理上呈现出由黑龙江下游至上游逐渐下降的趋势.3个种群间等位基因及基因型分布不均衡(P＜0.01),WS与HM、EM的遗传距离(Ds)分别为0.609 3、0.635 7,遗传分化系数(Fst)分别为0.068 0和0.0827,HM与EM亲缘关系最近,Ds和Fst分别为0.221 2和0.035 6,3个种群间的遗传距离及分化程度与地理距离呈正相关.AMOVA分子方差分析显示,6.35%的遗传变异来自于种群间,93.65%的变异来自于群体内个体之间.研究表明,黑龙江水系下游黑龙江茴鱼种群具有很高的遗传多样性水平,3个地理种群间产生了一定的遗传分化,推测其独特的生活史特性及地理距离是导致种群间产生遗传分化的主要原因.综合以上研究,建议将乌苏里江种群和黑龙江上游种群(呼玛河、额木尔河)作为下游黑龙江茴鱼的2个独特进化单元,并制订相应的保护管理策略.     

利用线粒体D—loop基因序列分析黑龙江上游北极茴鱼群体遗传结构

分布在黑龙江上游呼玛河和额木尔河等水域的北极茴鱼一新纪录种Thymallus sp,种群数量少、分布范围狭小,群体资源面临濒危。本研究采用PCR技术分析了黑龙江上游的北极茴鱼线粒体DNA控制区的序列,共获得了1104bp核苷酸全序列,与分布于勒拿河的该种茴鱼群体进行比较。结果显示：在23尾个体中共检测到3个单倍型（Hap1、Hap2,及Hap3）,其中Hap3为黑龙江和勒拿河共享;利用单倍型构建的分子系统树和网络图显示,黑龙江群体可能起源于勒拿河。黑龙江上游群体的遗传多样性较低,单倍型多样性指数（0.530）和核苷酸多样性（0.00053）远低于同域分布的其它种茴鱼;黑龙江群体与勒拿河群体的Fst为38.56%（P〈0.05）,已产生一定的遗传分化。     

茴鱼微卫星标记开发及保护遗传学研究进展

正茴鱼(Thymallus)隶属于鲑形目、鲑科、茴鱼亚科,是一类具有重要渔业价值的珍稀名贵冷水性鱼类[1-2]。目前已知该属鱼类主要有分布于欧洲的欧洲茴鱼(T.thymallus)、分布于北美洲的北极茴鱼(T.arcticus)和亚洲北部的其他茴鱼种和亚种。其中,亚洲东北部是茴鱼物种多样性最丰富的地区。在东西伯利亚地区的贝加尔湖、勒拿河、叶尼塞河及其他环北冰洋河流水系中分布有贝加尔茴     

黑龙江茴鱼部分胚后发育指标观察

黑龙江茴鱼俗称斑鳟子、红鳞鱼、鱼华等,系北冷温带一种典型的山涧溪流栖居的冷水性鱼类。其肉质鲜美,为黑龙江省特有的名贵食用鱼类。黑龙江茴鱼个体较小,生长速度相对稍慢且数量不多,未形成一定的捕捞量。由于天然水域的产量非常有限,难以满足日益增长的市场需求,加之当地渔民多在洄游期进行捕捞,捕捞强度过大,使原来就不多的资源量显著下降。此外,由于在河流上兴修水库和水利设施,改变了黑龙江茴鱼的产卵、摄食、越冬环境,对其繁殖和生存也造成了影响,使黑龙江茴鱼成为易危鱼类。为了充分开发利用这一名贵的土著鱼类,为人工培育苗种提供基础数据,本试验对黑龙江茴鱼部分胚后发育指标进行了研究。     

黑龙江水系主要冷水性鱼类年龄与生长特征的研究

1994～1996年对黑龙江水系的大麻哈鱼、哲罗鱼、细鳞鱼、乌苏里白鲑、黑龙江茴鱼等捕捞群体的年龄与生长特征进行研究,其生长速度较快的顺序依次为大麻哈鱼、哲罗鱼、细鳞鱼、乌苏里白鲑、黑龙江茴鱼。     

极具养殖价值的名特优鱼类——黑龙江茴鱼

黑龙江茴鱼系黑龙江省特有的名贵冷水性食用鱼类,其个体较小,生长速度相对稍慢。近年来,随着人们消费观念的转变,肉质鲜美、营养丰富的黑龙江茴鱼逐渐成为广大消费者青睐的名优水产品。由于天然水域的产量非常有限,人工养殖具有广阔的市场前景。一、习性与特征黑龙江茴鱼属鲑形目、茴鱼科、茴鱼属,俗称斑鳟子等。在我国产于黑龙江上游、嫩江上游、牡丹     

黑龙江茴鱼的人工繁殖

黑龙江茴鱼（Thymallus arcticus grubei Dybowski）属鲑形目、茴鱼科、茴鱼属，俗称斑鳟子，为一种典型的山涧溪流栖居冷水性鱼类。在我国自然分布于黑龙江流域的黑龙江、嫩江、牡丹江、乌苏里江、绥芬河等支流和溪流中，国外仅分布于俄罗斯境内。     

黑龙江茴鱼苗种培育及疾病防治

黑龙江茴鱼（Thymallus arcticus grubei Dybowski）属鲑形目，茴鱼科，茴鱼属，俗称斑鳟子、红鳞鱼、鱼华、海罗茨等，系典型的北温带小型溪居冷水性鱼类，在我国主要分布于黑龙江流域，国外主要分布于俄罗斯鄂霍次克海沿岸和日本海沿岸。黑龙江茴鱼属肉食性鱼类，以水生昆虫、甲壳类、小型鱼类等为主要食物，     

Daily rations and food availability of Japanese flounder Paralichthys olivaceus,small flounder Tarphops oligolepis and sand goby Favonigobius gymnauchen at a sandy beach in the central Seto Inland Sea,Japan

ABSTRACT:     To estimate the daily rations of Paralichthys olivaceus , Tarphops oligolepis and Favonigobius gymnauchen and to clarify diel variation in food availability to them, diel sampling was conducted over a 24-h period at a sandy beach in the Seto Inland Sea, Japan. The mean total length and body weight (BW) of P. olivaceus , T. oligolepis and F. gymnauchen were 32.6 mm (0.35 g), 23.7 mm (0.13 g) and 50.2 mm (1.03 g), respectively. The mean stomach contents index and percentages of stomachs with food were high during the day but low at night, indicating that these species are day-feeders. Paralichthys olivaceus and F. gymnauchen consumed mainly mysids and crangonids, whereas T. oligolepis fed chiefly on mysids. The estimated mean daily rations (95% confidence intervals) for P. olivaceus , T. oligolepis and F. gymnauchen made with the bootstrap method were 18.1 (9.3–31.3)%BW, 13.2 (7.9–24.3)%BW and 3.7 (1.7–7.4)%BW, respectively. Mysids were more abundant in the near-bottom layer during the day than at night, but the opposite was true for crangonids.     

Heavy infection of Ichthyophthirius multifiliis in striped catfish (Pangasianodon hypophthalmus,Sauvage 1878) and its treatment trial by different therapeutic agents in a control environment

ABSTRACT

Striped catfish (Pangasianodon hypophthalmus) fingerlings were stocked (60 fishes/m³) in cemented square tanks for ornamental fishery purposes at the College Fish Farm in Mangalore. A total of 400 fishes with a mean weight (g) ranging from 3.24 ± 1.21 to 6.70 ± 1.13 and a mean length (cm) of 7.50 ± 0.94 to 9.50 ± 1.10 were examined. A severe outbreak of salt-like granule white spots was found on the body surface. Ichthyophthirius multifiliis, a ciliate pathogen, was identified as the causative agent by clinical signs, wet mount, and histopathological observations. Infected fishes were transferred and equally distributed to the 0.45 m³ glass aquaria and treated with three treatments: (T1) methylene blue + salt; (T2) raising temperature with salt; and (T3) formalin + malachite green. The best fingerling survival (55 ± 9.36%) was obtained by elevated water temperature with salt in T2.     

中国林蛙蝌蚪饵料研究

本试验对中国林蛙蝌蚪期的3种不同饲料配方进行了试验研究。结果表明，T1组饲料喂养的蝌蚪变态后的幼蛙体重最大、身体最长（分别为0．347g、1．64cm）；T3组饲料所喂养的蝌蚪生长速度快，完成变态的时间最短（34．8d）；T2组饲料喂养的蝌蚪生长最慢，完成变态所需的时间最长（39．2d），变态后的幼蛙体重最小（0．276g）；各组中蝌蚪的成活率和变态率差异不显著（P〉0．05）。     

Mass mortality of short-tailed shearwaters in the south-eastern Bering Sea during summer 1997

During summer 1997, hundreds of thousands of emaciated short-tailed shearwaters ( Puffinus tenuirostris ) died in the south-eastern Bering Sea. Using strip transect methodology, we documented the distribution and abundance of short-tailed shearwaters during cruises conducted prior to, during, and after the die-off, as well as the distributions and abundances of floating carcasses. The distributions and abundances of short-tailed shearwaters in 1997 were similar to those found during the 1970s and early 1980s. In August–September 1997, we observed 163 floating shearwater carcasses, most of which were between St Paul Island and Nunivak Island. We estimated ≈ 190 000 carcasses were afloat in the study area, about 11% of the surveyed population. Between spring (June) and autumn (August/September), mean net body mass of shearwaters decreased by 19%, mean pectoral muscle mass decreased by 14%, and mean percentage body lipid content decreased by 46%, from 15.6% in spring to 8.4% in autumn. Compared with spring, short-tailed shearwater diets broadened in autumn 1997, to include, in addition to adult euphausiids Thysanoessa raschii, juveniles of T. inermis, T. raschii and T. spinifera, crab megalops, fish and squid. We discuss how the ecosystem anomalies in the south-eastern Bering Sea during spring and summer 1997 relate to the mortality event and suggest possible implications of long-term climate change for populations of apex predators in the south-eastern Bering Sea.     

Effect of cryoprotectants, equilibration periods and freezing rates on cryopreservation of spermatozoa of mahseer, Tor khudree (Sykes) and T. putitora (Hamilton)

A study was conducted to standardize a protocol for cryopreservation of spermatozoa of the endangered mahseer, Tor khudree (Sykes) and T. putitora (Hamilton). The suitability of the cryoprotectants, dimethyl sulphoxide (DMSO) and glycerol, and the combination of the two were tested. Four equilibration periods and four freezing rates were also tested for their standardization. A combination of 9% DMSO and 11% glycerol gave significantly higher mean percentage of hatching in both T. khudree (45.59±1.86%) (control 71.08±0.59%) and T. putitora (45.00±1.25%) (control 73.48±1.19%) among the eight different treatments. Among the four different equilibration periods tested, the equilibration period of 30 min^?1 yielded the highest mean hatching percentage in T. khudree (39.46±1.94%) (control 71.70±0.61%) and T. putitora (38.28±1.06%) (control 73.11±0.82%). Freezing straws at a height of 8 cm above LN₂ surface for 10 min^?1 gave higher hatching percentages for both T. khudree (41.75±1.72%) (control 73.99±1.17%) and T. putitora (41.34±2.04%) (control 72.48±1.51%). The study reports the superior performance of the combination of DMSO and glycerol for the first time.     

Shrimp rearing in biofloc integrated with different mullet stocking densities

This work compared the effects of different densities of Mugil curema integrated in the rearing of Litopenaeus vannamei in a biofloc system on the yield and ecological performance of the system. For that, an experiment lasting 55 days was conducted. Four groups were evaluated as follows: (a) T0: shrimp reared without mullet, (b) T10: shrimp reared with 22 fish per tank, (c) T20: shrimp reared with 43 fish per tank, and (d) T30: shrimp reared with 65 fish per tank, each treatment with four replicates. The sludge:biomass ratio was higher in the T0 treatment, while the T10–T20 treatments were more efficient, producing more biomass and less sludge. The use of water was 17% more efficient in all treatments with mullet. Mullet survival was higher in the T10 and T20 treatments (mean: 84 ± 8%) than in the T30 (61 ± 5%) treatment. The fish final biomass and yield limits of the system were 0.37 kg and 3.7 kg/m³ respectively. Finally, there was no increase in the total nitrogen output of the system up to the T10 density. In conclusion, it is possible to integrate mullet up to 3.7 kg/m³, increasing the yield in 20% and decreasing water use.     

Red blood cell indices of rainbow trout Oncorhynchus mykiss (Walbaum) in aquaculture

A direct non‐parametric method was used to calculate reference (physiological) haematology values for farmed 10–12‐month rainbow trout of the Kamloops strain (mean weight: 330±131 g) with respect to red blood cell counts (RBCc), haematocrit values (Hct), haemoglobin concentrations (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentrations (MCHC). The fish in the selected reference group (n=798) were given dry pelleted diets that contained 37–47% crude protein, 7–18% crude fat and 108–300‐mg vitamin E, 1.08–5‐mg folic acid, 0.018–0.05‐mg vitamin B₁₂, 48–64.5‐mg iron, 4.5–8.4‐mg copper and 0.18–0.24‐mg selenium supplied per kg of diet. Ethoxyquin and butylhydroxytoluol were used to protect the fat component against oxidation. The fish were kept at a stocking density of 50kg per cubic metre in tanks provided with running freshwater (dissolved oxygen 8.4–11.5 mg L^?1, with O₂ saturation of 77–98%) at an ambient temperature of 0.2–16°C. Blood was sampled between September and November at a photoperiod of 9–13 h:11–15 h (light:dark). Reference ranges for the preceding haematological indices were as follows in immature females (males): RBCc, 0.77–1.42T L^?1 (T – tera, 10¹²) (0.98–1.55T L^?1); Hct, 0.304–0.502 (0.34–0.546); Hb, 54–93 g L^?1 (59–97 g L^?1); MCV, 282–469 fL (279–434 fL); MCH, 51–86 pg (47–78 pg); MCHC, 0.15–0.22 (0.15–0.2). In males, values for RBCc, Hct and Hb were significantly higher (P=0.01 and 0.0000 respectively) and those for MCV, MCH and MCHC were significantly lower (P=0.01 and 0.0002 respectively) than in immature females. Nutritional and environmental factors affecting erythropoiesis in trout and some correlations between haematological (RBCc, Hb, Hct) and biochemical indices of the blood plasma (total protein, cholesterol) are discussed.     

Feed management for Pacific white shrimp Litopenaeus vannamei under semi‐intensive conditions in tanks and ponds

To improve feed management strategies for the semi‐intensive culture of Litopenaeus vannamei, outdoor tank and pond trials were conducted. In the tank trial, shrimp (35 shrimp/m², n = 4) were offered feed for 6 weeks based on a standard feeding protocol (SFP, designed as T100) with five variations (T80:90:100, T90, T90:100, T100:110, T110) of this protocol produced by varying the feed inputs and expressing the treatments as a percentage. Results demonstrated no significant differences in survival rate and feed conversion ratio (FCR) among treatments. The mean final weight and final biomass in the treatments T100:110 and T110 were significantly higher than those in treatment T90 but were not different from the other treatments. In the pond trial, juvenile shrimp (28 shrimp/m², n = 4) were stocked into twelve 0.1‐ha ponds over a 16‐week period. Three feeding protocols were evaluated including a SFP, a 10% reduction in the SFP (SFP:90), and a variable feed input (SFP:80:90:100), which included 80% SFP at week 4th–8th, 90% SFP from week 9th–12th and 100% SFP for week 12th–16th. There were no significant differences in growth performance and economic return among treatments. Based on previous studies, in which higher feed inputs were evaluated, and results of this study, it does not appear to be economically beneficial to use high feed inputs. Instead, feed input could be either applied at a standard ration to optimize growth and economic return or at restricted rations to reduce FCR (feed cost) albeit at the expense of some growth.     

Effect of dietary Wolffia arrhiza and Spirulina platensis on growth performance and pigmentation of Queen loach Botia dario (Hamilton, 1822)

The present Present experiment was conducted for 75 days in triplicates groups in 18 aquaria of 50 L each to study the effect of Wolffia arrhiza and Spirulina platensis on growth and pigmentation of Botia dario. Six isonitrogenous diets were prepared with 350 g/kg crude protein (CP) level. Diet 1 (T1) was prepared without fortification of spirulina and wolffia. T2 diet was prepared with spirulina as supplement of carotenoids. Similarly, T3, T4, T5 and T6 diets were prepared by substituting 25, 50, 75 and 100 g/kg of CP from spirulina with wolffia, respectively. Significant differences (p < .05) in final mean weight, mean weight gain, body weight gain and specific growth rate were observed. 100 percent survivability was recorded in T4 and T5. Final carotenoids content (μg/g) in skin (166.39 ± 2.71) and muscle (10.67 ± 0.32) was recorded highest in T5 and in whole fish in T6 (13.03 ± 0.95 μg/g). Redness, yellowness and whiteness found to have no significant differences (p > .05). Thus, it can be concluded that diet containing 100 g/kg spirulina can be effective for better growth while diet containing 25 g/kg spirulina and 150 g/kg wolffia can be effective for higher survival and pigmentation in Botia dario.