首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
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).  相似文献   

2.
The aim of this study was to develop a protocol for semen storage of piracanjuba (Brycon orbignyanus) by both cool storage at 4 °C and cryopreservation at − 196 °C. Semen was diluted in some fish semen extenders (Exp. 1) or in extenders combined with the antibiotic gentamycin sulfate (Exp. 2) and stored at 4 °C. Sperm motility was estimated every 24 h. Then, the effects of egg yolk (0 and 5%), cryoprotectants (dimethyl sulphoxide — DMSO, methanol, and methylglycol) and extenders (NaCl 154 mM, BTS™ Minitub and M III™ Minitub) on semen cryopreservation were evaluated (Exp. 3). Semen was added to each of eighteen cryosolutions (2 yolk concentrations × 3 cryoprotectants × 3 extenders), aspirated into 0.5-mL straws, frozen in nitrogen vapor (Taylor-Wharton, CP 300, “dry shipper”) and stored at − 196 °C. Sperm motility was evaluated after thawing at 60 °C-water bath for 8 s. The three cryosolutions that produced the highest post-thaw sperm motility were used again to freeze semen. Post-thaw semen quality was then evaluated under three tests: sperm motility, the percentage of live spermatozoa and hatching rate (Exp. 4). Piracanjuba semen diluted (1:10 total volume) in NaCl 200 mM or in Saad solution (NaCl 200 mM, Tris 30 mM) maintained motility above 35% for as long as 7 days, at 4 °C. Motility of only 7% was observed on undiluted semen after 3 days at 4 °C. There was neither beneficial nor detrimental effect of gentamycin on sperm motility at 250 μg/mL. Egg yolk addition to the cryosolution was beneficial in samples cryopreserved in NaCl 154 mM and in M III™, but detrimental for samples cryopreserved in BTS™. Methylglycol was the most effective cryoprotector compared to DMSO and methanol. Motility and percentage of live spermatozoa were similar among semen cryopreserved in NaCl–yolk, M III™–yolk and BTS™, all containing 10% methylglycol, but lower than fresh control. Hatching rates of eggs fertilized with sperm cryopreserved in NaCl–yolk or BTS™ were higher than for eggs fertilized with sperm cryopreserved in M III™–yolk, but lower than control fertilizations. The semen cryopreservation protocols developed here will be used to set up a gene bank for endangered piracanjuba populations.  相似文献   

3.
Sperm were collected in Florida from wild common snook, Centropomus undecimalis (Bloch), and were shipped to Louisiana State University for analysis and cryopreservation. Threshold activation of sperm (10% motility) occurred at 370 mOsmol kg?1, and complete activation occurred at 680 mOsmol kg?1. These values were significantly different. Sperm samples stored at 1°C in Hanks' balanced salt solution (HBSS) or in 0.6% NaCl solution at 200 mOsmol kg?1 retained motility for as long as 22 days. Mean motility remained above 50% for 9 days for sperm stored in HBSS and for 7 days for sperm stored in NaCl solution. Sperm exposed to 5% dimethyl acetamide (62±10%; mean±SD), 10% dimethyl sulphoxide (DMSO) (39±16%), 5% glycerol (26±5%) or 10% glycerol (6±2%) for 30 min had significantly lower motility than did unexposed sperm (89±9%). When used as a cryoprotectant, samples frozen with 5% or 10% DMSO or 5% methanol had significantly higher post‐thaw motility than did samples frozen with other cryoprotectants. Sperm cryopreserved with 10% DMSO (38±12%) had significantly higher post‐thaw motility than did sperm cryopreserved with 15% DMSO (19±10%) or 20% DMSO (4±4%). There were no significant differences in hatch rates of eggs fertilized with fresh sperm (54±29%) or cryopreserved sperm (41±35%). Survival to first feeding was not different between fish produced with fresh sperm (37±30%; range, 0–86%) or with thawed sperm (24±29%; 0–77%). Transport of sperm to a cryopreservation laboratory and back to a hatchery for thawing and use enabled collaboration between groups with specific expertise and provides a model for the application of cryopreservation by transport of fresh and frozen samples.  相似文献   

4.
This study investigated the effect of 0.25–5 mM K+, Ca2+, and Mg2+ on sperm motility in the perch, Perca fluviatilis. In 75 mM NaCl, the used motility-activating solution, motility rate, and swimming velocity decreased within the first 4 min after activation, and the rate of locally motile sperm increased. Thereafter, the motility parameters remained constant for periods >20 min. Based on the decrease in sperm motility, two types of semen samples could be distinguished. Semen samples of type I retained a high motility rate of >65 % after 20 min, and the rate of locally motile sperm was <20 %. In semen samples of type II, the motility rate decreased to values <30 % after 20 min, and the rate of locally motile sperm exceeded >50 %. Ca2+ and Mg2+ concentrations of 0.25–0.5 mM had no effect on the sperm motility parameters 10 s after activation, while 0.25 mM K+ increased the swimming velocity. K+, Ca2+, and Mg2+ concentrations ≥1.5 mM had suppressive effects on the sperm motility 10 s after activation. No differences were found between the two semen types. Twenty minutes after activation, type I semen was not affected by the tested cations. On the contrary, 0.25–2.5 mM K+, 0.25 mM Mg2+, and 0.25–2.5 mM Ca2+ significantly increased the sperm motility rate and/or sperm velocity of type II semen. Therefore, supplementation of saline solution with cations might stabilize the motility of perch sperm, which can be a benefit for experimental purposes and for specific handling procedures in aquaculture.  相似文献   

5.
The present study examined the possibility of long‐term storage, by cryopreservation in liquid nitrogen, of the sperm of filefish (Thamnaconus septentrionalis). Changes in motility, survival rate, ultrastructure and fertilization rate of the sperm after freezing and thawing were tested. For selection of the immobilizing solution, artificial seawater (ASW) of 250, 350 and 450 mOsmol kg?1 were tested. Sperm motility was significantly inhibited in 350 mOsmol kg?1 ASW, and restored entirely after 100% ASW (1200 mOsmol kg?1) was added. Two cryoprotectants, dimethyl sulphoxide and glycerol, were employed. The sperm was diluted at the ratio of 1:6 with the extenders, and frozen at a freezing rate of ?40°C min?1 to ?100°C after equilibration for 10 min at room temperature, followed by plunging into liquid nitrogen. The highest post‐thawed sperm motility and survival rate were obtained with 5% glycerol. Afterwards, the effect of different freezing rates was examined using 5% glycerol as a cryoprotectant, and the rate of ?30°C min?1 to ?100°C showed the best result.  相似文献   

6.
In two trials, Arctic char (Salvelinus alpinus) semen was frozen in 0.5 mL straws using extenders consisting of 0.3 M glucose and 10%, 12.5% or 15% methanol. Cryopreserved semen was thawed by immersing straws in 25 °C water for 17 s (11.6 °C s?1) or in 5 °C water for 60 s (3.3 °C s?1). The viability of the frozen–thawed semen was measured by determining post‐thaw motility and sperm membrane integrity. Two fertility trials were also conducted. There was no effect of trial or thaw rate on post‐thaw sperm viability or fertility. Use of 15% methanol in the extender resulted in the highest overall percentage of sperm motility and fertility. Use of 12.5% methanol as a cryoprotectant resulted in a higher per cent post‐thaw motility and a lower percentage of dead cells than did 10% methanol. Thus, levels of methanol higher than the commonly used 10% are beneficial for cryopreserving Arctic char sperm.  相似文献   

7.
Abstract Four parameters were examined in order to define sperm quality in turbot Scophthalmus maximus L., sperm: (1) sperm motility, measured by direct counts of the number of active spermatozoa, expressed as % of total spermatozoa; (2) retention of motility after activation, measured by direct counts, 0–60min after activation, expressed as a % of the initial level of activity; (3) resistance to thermal stress, measured as change in retention of motility, and (4) adenosine phosphate (ATP) concentration, determined for samples of non-activated sperm. The proportion of motile spermatozoa at activation ranged from 34·8% to 97·6% (mean 76·3%) for the individual males tested. Turbot sperm retained on average 52% (range 27–90%) of its initial activity one hour after activation. Sperm samples which were stressed by cooling to –27°C retained only 8·6% (range 0–25%) of initial activity, compared to control samples which retained 49% (range 38–63%) of initial activity. The retention of motility after activation was not significantly related to the initial motility or the levels of ATP. Concentrations of ATP in turbot sperm (mean 0·46mg ATP/106 spermatozoa, equivalent to 9·2nmol ATP/108 spermatozoa) were comparable to those measured in mammals.  相似文献   

8.
Abstract. The study includes mating and spawning data of freshwater crayfish, Austropotamobius pallipes Lereboullet, obtained in four consecutive years (1987–1990). A total number of 586 wild-caught female A. pallipes in the 21·65 mm to 45·60mm carapace length (CL) size were held under laboratory conditions at different dates in September–October. Initial densities at mating time were 21 and 24 crayfish/m2 with a 1:2 male:female ratio. High percentages of mating were obtained (97·4–100%) except in 1989 (57·5%). In all years, most of the matings (90%) were concentrated in a period of 8–12 days with mean water temperatures between 12°C and 13·5°C. Spawning took place a few days after mating (minimum 2 days, maximum 14 days) at mean water temperatures between 8·2°C and 10·8°C. In the first 3 years, almost 100% of mated females spawned. However, in the fourth year (1990), when the mean size of crayfish was smaller, only 72·4% of mated females spawned. The mean number of pleopodal eggs was 64 (maximum 220, minimum 18). Egg diameter ranged between 2·30 and 3·25 mm (mean value 2·78 mm). Pleopodal egg number was positively correlated with carapace length ( r = 0·72).  相似文献   

9.
Understanding the effects of environmental factors in sperm qualities will be helpful in the development of optimal artificial reproduction methods and contributes towards the knowledge base of better short‐ and long‐term fish semen preservation conditions The objectives of this study were to determine properties and activities of wild‐caught striped jewfish Stereolepis doederleini sperm contaminated with blood or seawater and compare them with data reported in the literature on other freshwater and marine fish species, for effective short‐ and long‐term storage of fish semen. Overall, we observed that the sodium, chloride, glucose, total protein concentrations of normal sperm were not significantly different from blood‐ or seawater‐contaminated sperm. The salinity and osmolality concentration of sperm contaminated with blood were lower than sperm contaminated with seawater and were not significantly different from normal sperm. In addition, the spermatozoa motility (SM) and duration of spermatozoa motility (DSM) in blood‐contaminated sperm were higher than seawater‐contaminated sperm and also not significantly different from normal sperm. The best condition for SM and DSM in normal sperm was dilution rate of 1:50. Sperm was immotile in distilled water, and cationic factors were shown to stimulate the initiation of spermatozoa activation. The maximum SM and DSM were observed in solution containing 0.4 M NaCl, 0.6 M KCl, 0.6 M CaCl2 and 0.4 M MgCl2. This study provides some basic and important knowledge about striped jewfish sperm sensitivity to a cationic condition. In this regard, Na+ is the major inhibitory factor of spermatozoa motility in this fish species.  相似文献   

10.
In the present study, attempts were made to preserve Urechis unicinctus sperm at 4°C. Cryopreservation procedures were optimized for various cryoprotectants and freezing rates, equilibration times and dilution ratios. During short‐term storage, the motility of undiluted sperm was extended for 6 days of cold storage,and in 70% and 100% artificial seawater only persisted for 2 and 4 days respectively. The survival rate of undiluted sperm was maintained at a high level accordingly. After cryopreservation, the highest motility and survival rate (41.5±2.2%) were obtained in 15% dimethyl sulphoxide (Me2SO) using a freezing rate of 30°C min?1. After thawing the sperm cryopreserved in glycerol lost almost all motility. The motility and survival rate of post‐thawing sperm did not show significant differences after 8 and 15 min equilibration using 15% Me2SO as cryoprotectant; the values were significantly higher than those of 2 min equilibration. Comparisons of motility and survival rate between treatments pooled by dilution ratio showed that the effect of 1:1 ratio (sperm volume to cryoprotectant volume) was best. There was no difference between 1:3 and 1:5, and other ratioswere significantly worse.  相似文献   

11.
Abstract. Field-caught fry of the common wolfish, Anarhichas lupus L., and the spotted wolffish, A. minor Olafsen, were reared on a commercial dry pellet. Both species experienced the same environmental conditions, including an annual fluctuation in temperature from 5·8 to 13·7°C. The spotted wolffish reached 1·58 kg in 2 years from hatching, more than four times the weight of common wolffish (0·37kg). Analysis showed that for both species the specific growth rate decreased with increasing fish size and increasing temperature. Estimates, based upon optimum conditions, indicate that the spotted wolffish would reach a total wet weight of 5 kg (<7°C) in 2 years from hatching, and the common wolffish (7–9°C) a total wet weight of 2·5kg within that same period. Female common wolffish matured at a weight above 0·5kg, whereas those of the spotted wolffish matured at a weight above 2·5kg. The spotted wolffish had a significantly higher fillet proportion (∼50%) than the common wolffish (∼45%) and a significantly lower hepato-somatic index (3·7% and 5% respectively).  相似文献   

12.
Semen of the African catfish, Clarias gariepinus (Burchell, 1822), was investigated with respect to its cellular composition, sperm cell density, maturation grade, motility and fertility. Storage conditions were tested, whereby sperm viability was assessed by measurement of the motility after activation and by fertility tests. Testicular semen differed in its composition, i.e. the sperm density and numbers of spermatids, according to the maturity grade of the testis. Two semen types could be distinguished: semen type I was characterized by high sperm densities and low numbers of spermatids and semen type II had lower sperm densities and higher numbers of spermatids. Two semen types did not differ in motility and fertility (when adjusted for differences in sperm density). During storage, the sperm viability was influenced by the sodium concentration of the storage medium, temperature, membrane stabilizers as bovine serum albumen (BSA) or hen egg yolk, antibiotics and oxygen. Semen viability was maintained best when it was diluted at a ratio of 1:5 in storage solution (150 mmol L?1 NaCl, 2.5 mmol L?1 KCl, 1 mmol L?1 CaCl2, 1 mmol L?1 MgSO4, 20 mmol L?1 Tris (pH 8.5) and 0.5% BSA or 0.5% hen egg yolk) and stored at 4 °C. Oxygen gassing and addition of antibiotics (1 mg mL?1 gentamycine sulphate) to the storage solution affected the two semen types in different ways. Antibiotics had no effect on type I semen, but had a positive effect on type II semen. Oxygen gassing had a positive effect on type I semen but a negative effect on type II semen.  相似文献   

13.
The addition of cryoprotectants during the freezing of semen in liquid nitrogen protects spermatozoa from the negative influence of freezing. Every species needs an appropriate cryoprotectant that has to be experimentally selected. Semen obtained from five perches was diluted with the Kobayashi buffer solution at 1:9 ratio. To determine the influence of cryoprotectants on spermatozoa motility parameters, the same type of buffer solution was applied with the addition of methanol, dimethyl sulfoxide (DMSO) and dimethylacetamide (DMA) using the concentration of 10, 5, 2.5 %, respectively, glycerol (15; 7.5 %), sucrose and trehalose (0.45; 0.225; 0.113 M). After the preparation of such tests, parameters of spermatozoa motility were measured, using the CASA system (Image House CRISMAS Company Ltd.). Among used cryoprotectants, methanol did not cause any effect on the sperm motility parameters. The lowest percentage concentrations of DMA, DMSO, glycerol, sucrose and trehalose did not significantly influence the percentage of motile spermatozoa. Higher concentrations of these compounds considerably lowered all motility parameters. As for glycerol and saccharides, their addition resulted in the lowering of the spermatozoa motility possibly due to a higher viscosity of the solution. However, DMA and DMSO were most probably toxic to perch sperm cells. The obtained results indicate that the best cryoprotectant to be used with perch spermatozoa is methanol.  相似文献   

14.
In this study, the efficiency of a novel droplet vitrification technique along with different doses of fish antifreeze protein (AFP) type III on Persian sturgeon thawed spermatozoa quality (motility duration and motility percentage) was investigated. Semen of seven male individuals was pooled in equal volumes and diluted with 4°C Tris‐Hcl (100 mM), pH = 8 extenders containing 0, 5, 10, 15 μM of AFP type III in a ratio of 1:1 (semen/extenders). Treated semen was dropped into liquid nitrogen. Solidified droplets were stored for 2, 60 and 120 days and thawed by plunging them into a tube containing 5 mL Tris‐Hcl (100 mM), pH=8 with 1% BSA at 37°C. Motility duration in all treatments had no significant difference comparing to fresh sperm (P > 0.05), but their motility percentage was significantly lower. Treatment with 10 μM of AFP had significantly higher motility percentage (16.11 ± 0.5%) comparing to other treatments (P < 0.05). There was no significant difference between 0, 5, 15 μM of antifreeze protein treatments (P > 0.05), suggesting that antifreeze protein effectiveness are highly dose dependent, and dose of 10 μM is appropriate in Persian sturgeon spermatozoa droplet vitrification. Besides, the present technique obtained higher quality of spermatozoa comparing to its analogue techniques.  相似文献   

15.
Abstract.— Two experiments were designed to improve upon existing methods for cryopreserving striped bass Morone saxatilis , semen. In the first experiment, two extenders, two cryoprotectant concentrations, and two freezing rates were evaluated on the basis of post-thaw semen motility after 1, 7, and 30 d of storage at −196 C. Semen samples cryopreserved at a freezing rate of −40 C/m resulted in a significantly higher percentage of motile sperm ( P < 0.001) and longer duration of spermatozoa motility ( P < 0.001) than samples cryopreserved at a freezing rate of -30 Chin. Also, the cryoprotectant dimethyl-sulfoxide yielded a significantly higher percentage of motile sperm ( P < 0.001) and longer duration of spermatozoa motility ( P < 0.001) when a 5% concentration was used instead of 7.5%. In the second experiment, the two extenders from Experiment I were re-evaluated and a new extender, which was a modified version of Extender 1, was tested. The samples were cryopreserved at -40 C/min with 5% DMSO and thawed in a 25 C water bath. Spermatozoa motility and fertilization ability were evaluated, and semen cryopreserved in Extender 2 yielded the longest duration of spermatozoa motility ( P < 0.001). the highest percentage of motile sperm ( P < 0.001). and the highest percentage of fertilized eggs ( P < 0.002) in comparison to Extenders I and 3.  相似文献   

16.
Abstract. The eggs and yolk sac fry of the mouth brooding tilapia. Oreochromis mossambicus (Peters), were artificially reared in an experimental hatchery system at different temperatures. The hatchability, embryonic development of eggs and growth of yolk sac fry were studied under controlled conditions. It was shown that the upper lethal temperature for O. mossambicus eggs was above 40°C and the lower lethal temperature between 11°C and 17°C. For yolk sac fry these values lay between 34 and 40°C and 17 and 20°C respectively. Fry survival between 24·3 and 34·0°C was near to 100% while al 20°C it was less than 60%. The somatic growth rates of fry at temperature between 20 and 34·5°C up to 10 days post hatch are presented and were found to differ significantly. At 34·6°C a negative SGR was recorded during the period 6–9 days post hatching, but, during the first 6 days, the SGR at this temperature was more than four times higher than at 20°C. At the elevated temperatures, the utilization of yolk is faster and the loss of weight observed was due to starvation. This should be taken into account when incubating under artificial rearing condition so that initiation of exogenous feeding is timed most appropriately.  相似文献   

17.
Abstract. Hatching responses of the Japanese whiting, Sillago japonica Temminck et Schlegel, to a series of temperature changes were measured by exposing the fertilized eggs to eight constant incubation temperatures which ranged from 20·0 to 34·0°C. For a control, hatching temperature was kept the same as temperature of the ambient environment. Hatching responses were expressed as hatching percentages. Altogether 18 experimental trials were conducted during the natural spawning season of the species which extended over a period of 2 months from late July to mid-September 1988, when seawater temperature varied between 24·0 and 30·0°C. Optimum and limiting temperatures were recorded and the data were optimally fit to the quadratic model. Results indicated that viable hatch occurred at almost all ranges of hatching temperature from 22·0 to 32·0°C. However, no hatching was recorded at either 20·0 or 32·0°C. The experiment showed that the optimum hatching temperature varied with the ambient temperature changes during the spawning season, indicating the latter to be a dependent factor for any hatching success.  相似文献   

18.
Cryopreservation of sea cucumber Apostichopus japonicus (Selenka) sperm   总被引：1，自引：0，他引：1  
A simple and convenient method for the cryopreservation of sea cucumber Apostichopus japonicus (Selenka) sperm was tested in the present study. The highest motility (76.7±2.9%) of post‐thawing sperm was obtained in 15% dimethyl sulphoxide (DMSO) with a 1:9 dilution (semen volume to DMSO volume) when 0.5 mL semen–DMSO mixture was frozen at 6 cm above liquid N2 in a closed styrofoam box. After thawing, sperm cryopreserved in glycerol almost lost motility entirely. Although there was no significant difference in percentage of motile sperm between 15% and 20% DMSO, the duration of sperm motility of 15% DMSO group was longer than that of 20% DMSO group. The motility of post‐thawing sperm enhanced when the dilution ratio of semen increased from 1:1 to 1:9. Morphological changes such as the loss of mitochondria, swollen plasma membrane and broken or rolled‐up tails were observed in post‐thawing sperm using an eosin–nigrosin staining. The fertility of cryopreserved sperm was significantly lower than that of unfrozen sperm. The 10‐fold increase in sperm to egg ratio resulted in double fertility for cryopreserved sperm, and about 70% fertility relative to the control.  相似文献   

19.
Abstract. Four feeding trials with Israeli carp, Cyprinus carpio L., were performed in cages or in ponds in order to investigate responses to lysine supplementation of low protein carp feeds under different practical conditions. In each of the trials one of the basic conditions was different: fish size—small (80–125g) or large (560g); temperature—22°C or 26°C; density—cages or ponds. In each trial 2–3 ration sizes × 2–3 lysine levels were tested. A basal diet of 25% protein and 1·35% lysine served for all the trials.
At low feeding levels, no responses to lysine supplements were found either at 22 ± 2°C or at 26 ± 2°C (0600 h) for all fish sizes. At higher feeding levels, at both temperatures, 0·5% lysine-HCl supplements to 1·7% total lysine yielded significant growth increases. Further supplements to 2·1% lysine (=8·4% of the protein) brought an additional response only from small fish of 90g in cages at the highest ration and temperature. In ponds at 26°C, the effects on small fish of 80g were smaller, probably due to available natural food. The reduction in lysine retention suggested that 1·7% lysine might have been adequate even at optimal conditions in ponds.  相似文献   

20.
Cryopreservation of semen collected from dead fishes showed that it is possible to use it for fish production. We humanely killed individuals of the Indian major carp rohu, Labeo rohita and stored at different temperature regimes of 31 °C, 0 °C, − 10 °C and − 30 °C till 8 h. At every one hour interval semen from these fishes were collected by Pasteur pipette and evaluated for sperm yield/kg body weight, motility, pH, spermatocrit (%) and sperm count. The semen having suitable characteristics such as; 70% spermatocrit or above and motility index of 4 or above was cryopreserved by following a specific protocol. The cryopreserved semen of the dead fishes was stored for 7 days and then thawed in a water bath at 37 °C for 50 s. It was found that up to 8 h, spermatozoa of rohu were viable when stored at 0 °C or − 10 °C. Sperm collected after 8 h of fish death and maintained at 0 °C was the best stored condition that showed 30% larval survival. The spermatozoa collected 8 h after fish death was mostly normal as observed under scanning electron microscope and the total length of rohu spermatozoa was 25-30 μm. The hatchlings produced with this cryopreserved semen grew normally and juvenile fishes of rohu could be produced. This study suggests that germ cells such as spermatozoa of dead fishes can be cryopreserved and utilized for restoration of a species. It has the potential use in cryo-conservation of endangered fishes, restoration of animals through fertilization and genetic manipulation studies.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号