Semen cryopreservation in the Salmonidae and in the Northern pike

The present paper summarizes the data on a semen cryopreservation method for the Salmonidae (Oncorhynchus mykiss, Salmo trutta f. lacustris, Salvelinus fontinalis, Salvelinus alpinus, Salmo trutta f. fario, Hucho hucho, Coregonus lavaretus, Thymallus thymallus) and for the Northern pike (Esox lucius) published during recent years. It describes (1) methods used for the determination of sperm viability; (2) the protective efficiency of substances specifically for protection of internal and external parts of cells and the process of extender development; (3) the freezing, thawing and fertilization conditions; and (4) the tolerable deviations from the freezing protocol for more easy application. Finally, biomarkers are reported that predict the suitability of semen for cryopreservation and the quality of frozen–thawed semen.     

The effect of water temperature on gamete maturation and gamete quality in the European grayling (Thymalus thymallus) based on experimental data and on data from wild populations

To investigate the effect of water temperature on gamete maturation and gamete quality, European grayling (Thymalus thymallus) were held under different temperature regimes prior to spawning. Maturation of males and females and their gamete quality depended strongly on temperature regime. The highest percentages of maturing fish and highest gamete quality were obtained under a creek water temperature regime with natural seasonal fluctuations. In warmed creek water (3–4°C), at a constant temperature of 8–9°C, and under an abruptly increasing temperature, regime maturation rates and gamete quality were reduced. The effect was more pronounced in females than in males. The spawning dates of different wild Austrian grayling populations were also correlated with water temperature data collected during the last 10–15 years. The mean spawning date expressed as the number of days from 21 December until spawning ranged from 98 to 111 days for lower elevation populations, while it was considerably delayed for an alpine population. All populations spawned at water temperatures of 5.5–7.2°C. Regression analysis indicated that spawning date correlated with (1) the overall mean water temperature from 21 December until spawning, (2) the mean water temperature during both the last 10 days and 15 days before spawning, and (3) the difference between mean January temperature and that of the last 15 days before spawning. The regression functions indicate that an increase in water temperature from 21 December to spawning of 1°C advances spawning by 5? days, and an increase of 1°C in the last 10–15 days advances spawning by 3? days.     

Egg-sperm interaction in sturgeon: role of ovarian fluid

Fish Physiology and Biochemistry - Fertilization of freshwater fish occurs in the environment which negatively affects a lifespan of gametes mostly due to the osmotic shock; therefore, male gametes...     

Effects of egg aging on the metabolites of ovarian fluid in rainbow trout,Oncorhynchus mykiss

Nuclear magnetic resonance ‐based metabolomics was applied to study effects of egg aging on ovarian fluid metabolites in rainbow trout, Oncorhynchus mykiss. The eggs of three females were pooled and then assigned to three plastic vials for 18 days in vitro storage at 4°C. Ovarian fluid samples were taken 0, 6, 12 and 18 days after storage. Three groups of metabolites including amino acids, osmolytes and energy metabolites were found to change during storage period. The glucose levels of ovarian fluid showed significant decreases on days 12 and 18 after storage (p < .05). For acetoacetate and acetate, significant increases were observed, respectively, on days 12 and 18 after storage (p < .05). The creatine levels of ovarian fluid increased significantly on days 12 and 18 after storage (p < .05). Lactate levels in ovarian fluid elevated during storage period (p < .05). Glycerol levels showed a significant increase on days 12 and 18 after storage (p < .05). The values of osmolytes in ovarian fluid (e.g., betaine, taurine, trimethylamine‐N‐oxide, N,N‐dimethylglycine) showed a decreasing trend on day 12 which continued until the end of storage on day 18 (p < .05). Almost all amino acids elevated on days 12 and 18 after storage (p < .05). After an apparent elevation in isoleucine levels on days 6 and 12, this amino acid decreased on day 18 after storage (p < .05). The osmolytes might act as antioxidant against free‐radicals produced as a result of over‐ripening. Glucose can be used as energy resource for eggs and bacteria during ova storage. Also, change pattern of amino acids indicate hydrolysis of proteins as the time of storage increases.     

鱼类精氨酸营养生理研究进展

精氨酸为鱼类的必需氨基酸之一，其在鱼体内参与蛋白质、多胺的合成，促进生长；精氨酸具有促内分泌作用；精氨酸可在体内生成一氧化氮，一氧化氮参与鱼类心血管活动、免疫功能的调节。某些鱼类可能具有自身精氨酸的合成能力。鱼类赖氨酸一精氨酸拮抗存在种问差异。本研究从精氨酸的合成、生理功能、与赖氨酸的关系以及需求量等方面对鱼类精氨酸的营养生理研究进行了综述。[中国水产科学，2006，13（4）：679-685]     

海洋贝类配子及胚胎的低温冷冻保存

综述了海产贝类配子及胚胎的低温冷冻保存技术的发展现状,对目前的文献进行了汇总和分析,讨论了冷冻保存的降温程序、抗冻剂配方以及评价保存效果的指标等方面的问题,并对目前在海产贝类配子和胚胎的低温冷冻研究方面存在的问题和解决的途径进行了探讨。     

The effect of body size on post-exercise physiology in largemouth bass

Variation in individual size has important consequences for a number of characteristics of fish, which can impact fish populations. The impact of fish size on recovery following exercise, however, is poorly understood, with little information existing on the recovery of ionic/osmotic variables. The goal of this study was to quantify not only how allometry impacts the magnitude of physiological disturbance following burst exercise in largemouth bass (Micropterus salmoides), but also how allometry impacts the time required for exercise-induced disturbances to return to baseline levels. To accomplish this goal, two size classes of largemouth bass (large = 772–1,441 g total weight, mean = 1,125 g; small = 93–238 g, mean = 148 g) were exercised for 60 s and allowed to recover for 0, 1, 2, or 4 h before being sampled for plasma and white muscle. Large largemouth bass exhibited elevated concentrations of plasma glucose and sodium relative to small fish following a common exercise challenge. Large fish required additional time to clear metabolic disturbances in plasma and failed to restore potassium to basal levels even following 4 h of recovery, indicating an improved ability of the smaller fish to recover from disturbances. Results are further discussed in the context of physiological ecology and fitness for largemouth bass.     

哲罗鲑卵子和卵腔液的生化组成与其发眼率的相关性

为了解哲罗鲑(Hucho taimen)卵子及卵腔液的生化组成及其与发眼率的关系,采用生物化学的方法对雌性哲罗鲑Ⅴ期卵子及卵腔液的酶、蛋白质﹑氨基酸﹑维生素和矿物质等组成和含量进行了测定,并且将各组份与哲罗鲑受精卵的发眼率进行了回归分析。结果表明:哲罗鲑Ⅴ期卵子中含有碱性磷酸酶、酸性磷酸酶、谷草转氨酶、琥珀酸脱氢酶﹑Mg2+-ATP酶﹑磷﹑钙离子﹑铁离子﹑维生素C和维生素E。卵子中Mg2+-ATP酶活力≥8.3×10-5μmol(Pi)/(min.mg prot)、磷含量在12.97~23.0 3μmol/g(卵)之间及氨基酸含量在574.89~1195.40μmol/g(卵)之间,哲罗鲑卵的发眼率均≥80%。哲罗鲑的卵腔液中含有碱性磷酸酶、酸性磷酸酶、谷草转氨酶、琥珀酸脱氢酶、磷、钙离子、铁离子、维生素C和维生素E,当谷草转氨酶酶活力≥18.14μmol/(min·L),哲罗鲑卵的发眼率≥80%。哲罗鲑Ⅴ期卵子中Mg2+-ATP酶活力、磷含量﹑氨基酸含量以及卵腔液中谷草转氨酶酶活力与其发眼率存在着显著相关性。     

Hybrids between Salmonidae species. Hatchability and growth rate in the freshwater period

In 1972 a hybridization experiment with salmonids was initiated at the Fish Breeding Experimental Station, Sunndalsøra. The purpose of this experiment was to study the viability, performance traits and the fertility of hybrids. Hybrids were produced from the following members of the salmon family: Salmon (Salmo salar), sea trout (Salmo trutta), brown trout (Salmo trutta), rainbow trout (Salmo gairdneri) and arctic char (Salvelinus alpinus). All crosses attempted, except those involving the rainbow trout, were relatively successful. Considerable differences in the hatching rates of the different hybrids were observed. All crosses with the arctic char were heavier than the better pure bred specimens at 11 months. In all other crosses the hybrids were lighter than the purebred specimens. The experiment is continuing, it is evident that more research is necessary before the potential value of these hybrids for fish farming can be properly assessed.     

我国鲟类生理学研究现状

我国对鲟类生理学作较全面的研究实际始于７０年代,这包含生殖生理学、摄食生理学、消化生理学、营养生理学等方面内容的研究,至９０年代由宏观研究渐趋微观研究。我国鲟类生理学的研究已接近国际水平。本文就我国近些年鲟类生理学主要研究结果简述如下。１鲟类生殖生理...     

Steroids and steroid glucuronides in the ovarian fluid of the African catfish,Clarias gariepinus,between ovulation and oviposition

As part of a series of experiments concerning a possible pheromonal function of steroids and steroid glucuronides excreted by the sex organs of the African catfish,Clarias gariepinus, qualitative and quantitative studies, using GCMS, were carried out to examine the presence of the steroids, that can be synthesized by the ovary during oocyte maturation and ovulation, and of the corresponding steroid glucuronides, in the fluid surrounding the eggs in the ovarian cavity shortly after ovulation.Full mass spectra were obtained of 5-pregnane-3,17-diol-20-one, 5-pregnane-3,17,20-triol, 5-pregnane-3,6,17-triol-20-one, 5-pregnane-3,6,17,20-tetrol, 5-androstane-3,17-diol and 5-androstane-3,17-diol-11-one. After selected ion monitoring the following steroids could be detected by the presence of at least two characteristic ions at the expected retention time: 5-pregnane-3, 17,20-triol, etiocholanolone, 5-dihydrotestosterone, 5-androstane-3,11-diol-17-one, testosterone and estradiol. After treatment with -glucuronidase the following steroids could be determined in a similar way: 5-pregnane-3,17-diol-20-one, 5-pregnane-3,17,20-triol, 5-pregnane-3,17,20-triol, 5-pregnane-3,6,17-triol-20-one, 5-pregnane,3,6,17,20-tetrol, 5-androstane-3,17-diol, etiocholanolone, 5-dihydrotestosterone, testosterone and estradiol.The free steroids 5-pregnane-3,6,17,20-tetrol and 5-pregnane-3,6,17-triol-20-one and the steroid glucuronides of testosterone, 5-dihydrotestosterone and estradiol appeared to be the most abundant of these compounds. The results indicate that very polar steroids and steroid glucuronides, synthesized in the ovary, can be excreted via the ovarian fluid shortly before and during oviposition, and possibly function as sex attractants, inducing reproductive behaviour in male conspecifics.     

光照强度和氮营养盐浓度对龙须菜生理代谢的影响

以龙须菜(Gracilaria lemaneiformis)为材料,以无机氮(NO_3~-︰NH_4~+=2︰1)为氮源配制人工海水,将在低光低氮(L-N-)条件下培养的龙须菜部分给予高光照处理(L+N-),同时另一部分在给予高光照的同时给予更充足的氮源(L+N+),通过测定3种不同处理条件下物质积累、光合色素以及碳氮代谢中的关键酶等多种生理指标,探讨光照强弱与氮源多寡对龙须菜生理代谢的影响。结果表明,在低氮培养时,高光可使藻体可溶性蛋白、含水率、藻红蛋白和叶绿素a的含量下降,而可溶性糖含量上升13.67%;高光培养时,高氮使可溶性蛋白、含水率、藻红蛋白和叶绿素a的含量上升,而可溶性糖含量下降16.3%;相对于低光低氮(L-N-),高光高氮(L+N+)条件培养使藻体中可溶性蛋白和藻红蛋白含量增加,其含水率、叶绿素a和可溶性糖含量并无显著性差异(P0.05)。从上述结果可以看出,补充氮源能够在一定程度上消除高光照对藻体产生的影响,保证藻体基本生理状态不发生变化的情况下积累蛋白(氮源)。同时补充氮源使得谷氨酰胺合成酶(GS)和天庚酮糖-1,7-二磷酸酶(SBPase)的表达均下调,也反映了光合作用所产生的三碳化合物在氮源充足的条件下主要流向了氮循环。而高光照并未对碳氮代谢关键酶的表达产生影响,可能通过直接破坏叶绿素a而影响藻体的光合作用。     

雌性羊驼繁殖生理研究进展

与其它家畜相比,雌性羊驼呈现的繁殖特性对于研究者来说相对较陌生。本文旨在综述雌性羊驼生殖生理学上的研究进展,介绍其生殖系统的解剖学特征,未交配和已交配雌性羊驼的繁殖特点等。     

First results on a relation between ovarian fluid and egg proteins of Salmo trutta and egg quality

By use of sodium dodecyl sulfate polyacrylamide gel electrophoresis, ovarian fluid proteins and main proteins of unfertilized eggs were qualitatively and quantitatively investigated in the brown trout, Salmo trutta, to see whether some of them were correlated with the rate of embryos reaching the eyed embryo stage. In the ovarian fluid, 12 types of proteins in the range of 39–166 kDa were detected whereby three proteins were lipoproteins and two were glycoproteins. Ovarian fluid proteins with a molecular weight of 85, 68, 62 and 39 kDa were negatively correlated with the percentage of eyed stage embryos. The statistical significance of the relations was low in simple and multiple regression models (R²≤0.534) indicating that the relations were influenced and superposed by other factors. Therefore, ovarian fluid proteins give only poor information about maturity and quality of eggs. In the eggs, nine major types of proteins in the range of 95–15 kDa were identified. The 95 kDa protein was a lipoprotein, the 85 and the 62 kDa protein were glycoproteins, and the 15 kDa protein was a phosphoprotein. The 95, 85, 77 and 39 kDa protein were positively correlated with embryo survival to the eyed embryo stage. The explanatory effect of the multiple regression model was very high (R²=0.961) indicating that distinct egg proteins are closely related with egg quality.     

Studies on the structure and physiology of salmon teleocalcin

The structure and physiology of salmon teleocalcin, a Ca⁺² regulating hormone from the corpuscles of Stannius (CS) is reviewed. Teleocalcin is produced by the PAS+, type 1 cells in the CS. The hormone is a disulfide-linked homodimer, with a unique amino acid sequence and a carbohydrate moiety on residue 29. The teleocalcin monomer has a MW of 30 KD, whereas the pro-form of the monomer is 32 KD. The hormone is positively regulated by Ca⁺² and its function is to slow the active transport of Ca⁺² across the gill epithelium. In conjunction with prolactin, which stimulates Ca⁺² transport, teleocalcin is one of the major factors involved in Ca⁺² homeostasis in fish.     

盐度变化对斜带石斑鱼生理生化因子的影响

采用生化分析方法研究了盐度变化(24、14、4及对照34)对斜带石斑鱼幼鱼(体重19.59?0.25g)相关生理生化因子的影响,在盐度处理后1 d、3 d、6 d和9 d取样并检测鳃丝Na /K -ATP酶、血清中血糖、天门冬氨酸氨基转移酶(AST)、溶菌酶,肝脏超氧化物歧化酶(SOD)含量及H.E染色观察鳃丝氯细胞的变化。结果显示：各盐度试验组斜带石斑鱼幼鱼的Na /K -ATP酶活性变化基本一致,均在第3 d达到最高值,随后下降,至第6 d达到稳定。鳃丝氯细胞数量在盐度24试验组中变化不大,在盐度14试验组中则略有减少,在盐度4试验组中鳃丝氯细胞6 d后出现变化,氯细胞数量减少,胞核较大,H.E染色较深,细胞处于较原始的状态。各盐度试验组斜带石斑鱼幼鱼的血糖水平变化趋势相一致,均在第6 d到达峰值,随后呈下降趋势。AST水平在盐度24、盐度4试验组随时间的延长呈上升趋势,在第9 d后到达各自的最高值,盐度14试验组则呈现持续下降趋势。SOD活性随时间的延长呈现先降低后上升的趋势,在第3 d时各试验组达最小值,但试验组间SOD活性差异显著 (P＜0.05)。溶菌酶活性随时间的延长呈上升趋势,试验组在第6 d达到的峰值,随后下降并趋于稳定,试验组间差异显著(P＜0.05)。结果表明,斜带石斑鱼幼鱼通过盐度驯养,由盐度34水体逐渐淡化至盐度为24、14、4的水体中,能较快适应盐度低至4的水环境。本研究为低盐度地区淡化养殖石斑鱼提供依据。     

Environmental influences on life history strategies in partially anadromous brown trout (Salmo trutta,Salmonidae)

This paper reviews the life history of brown trout and factors influencing decisions to migrate. Decisions that maximize fitness appear dependent on size at age. In partly anadromous populations, individuals that attain maturity at the parr stage typically become freshwater resident. For individual fish, the life history is not genetically fixed and can be modified by the previous growth history and energetic state in early life. This phenotypic plasticity may be influenced by epigenetic modifications of the genome. Thus, factors influencing survival and growth determine life‐history decisions. These are intra‐ and interspecific competition, feeding and shelter opportunities in freshwater and salt water, temperature in alternative habitats and flow conditions in running water. Male trout exhibit alternative mating strategies and can spawn as a subordinate sneaker or a dominant competitor. Females do not exhibit alternative mating behaviour. The relationship between growth, size and reproductive success differs between sexes in that females exhibit a higher tendency to migrate than males. Southern populations are sensitive to global warming. In addition, fisheries, aquaculture with increased spreading of salmon lice, introduction of new species, weirs and river regulation, poor water quality and coastal developments all threaten trout populations. The paper summarizes life‐history data from six populations across Europe and ends by presenting new research questions and directions for future research.     

有效氯对浮游植物生长的影响

用０．５×１０－６和１．０×１０－６有效氯处理虾池浮游植物,用４．０×１０－６、１００×１０－６和１５０×１０－６有效氯处理叉鞭金藻、球等鞭金藻两个品种（９００２、３０１１）、巴夫藻（３０１２）、塔胞藻和小新月硅藻,结果表明,０．５×１０－６—１．０×１０－６的有效氯对虾池浮游植物产氧有严重抑制,但对叶绿素含量无显著影响;金藻类用１５０×１０－６有效氯处理１．５ｈ仍可存活,但小新月和塔胞藻在有效氯为４．０×１０－６时,短时间即可致死。     

The ovarian regulation of ovulation in teleost fish

Ovulation is the release of a mature oocyte from its follicle wall enclosure in the ovary. This process requires the separation of the oocyte from the granulosa layer, the rupture of the follicle wall and the active expulsion of the oocyte through the rupture site. Results of experiments on various vertebrates, including fish, have shown that the control of these processes may involve the cooperative action of a number of ovarian regulators including proteases, protease inhibitors, progestational steroids, eicosanoids, catecholamines and vasoactive peptides. We have used two teleost models, the brook trout (Salvelinus fontinalis) and the yellow perch (Perca flavescens) to study the mechanism and control of ovulation in fish. Using subtractive cDNA cloning, a family of ovarian and ovulation specific mRNAs (TOPs = trout ovulatory proteins) was isolated from the brook trout ovary. These mRNAs have not previously been observed in the ovary of any vertebrate species; however, the proteins they code for have significant sequence homology to a group of mammalian protease inhibitors called antileukoproteinases. These inhibitors have been isolated from several mammalian mucosal tissues and their function may be to protect the mucosal lining from nonspecific degradation by proteases released from infiltrating leukocytes. The ovarian proteins encoded by the TOP mRNAs have now been characterized by Western blotting using antibodies derived against recombinant TOPs. Given the similarity of TOPs to antileukoproteinases, one function of TOPs may be to regulate proteolysis at the time of ovulation. In yellow perch, the maturational steroid, 17,20-dihydroxy-4-pregnen-3-one (17,20-PG), stimulates both germinal vesicle breakdown and ovulation in vitro. The stimulation of ovulation can be blocked by indomethacin, a prostaglandin endoperoxide synthase inhibitor. Thus, it appears that 17,20-PG acts through the production of an eicosanoid that is most likely a primary prostaglandin. This hypothesis is further supported by the observations that (1) a direct correlation exists between indomethacin levels that block ovulation and those that block primary prostaglandin synthesis in the ovary; (2) ovulation can be restored in indomethacin-blocked incubates with primary prostaglandins; (3) PGF levels increase at the time of ovulation in incubations of yellow perch follicles stimulated with 17,20-PG; and (4) the stimulation of PGF by steroids in the ovary is specific for 17,20-PG. Finally, 17,20-PG-stimulated ovulation and follicular prostaglandin synthesis requires the close interaction of extrafollicular tissue and other follicle wall layers.     

Broken eggs decrease pH of rainbow trout (Oncorhynchus mykiss) ovarian fluid

Low pH of ovarian fluid is attributed to its inability to activate sperm motility. In the present study we sought if broken eggs are reason for the decrease of ovarian fluid pH. We examined if 1) there is relationship between turbidity of ovarian fluid (indicator of presence of broken eggs) and pH, and 2) there is a decrease in ovarian fluid pH after addition of broken eggs. We found a negative relationship between the turbidity and ovarian fluid pH. Addition of the content of broken eggs to ovarian fluid caused a decrease of pH and a decrease in ovarian fluid ability to activate sperm motility. Therefore it can be suggested that content of broken eggs decreases or negates the ability of ovarian fluid to activate sperm motility due to a decrease of pH.