共查询到20条相似文献，搜索用时 484 毫秒
1.
2.
珠母贝插核育珠的初步观察 总被引：5，自引：0，他引：5
珠母贝插核育珠,选择壳高7～9cm的母贝作为插核贝和以外套膜颜色相同的插核贝、小片见组合进行括核育珠的效果较好。珠母贝括核手术后休养期的存活率为77．5％～97．3％,留核率为42．5％～77．4％。壳高7～9cm的插核见成珠率为25．0％,已接近马氏珠母贝生产上的插核育珠水平。 相似文献
3.
本研究比较了不同术前处理方式和不同规格珠核对企鹅珍珠贝(Pteria penguin)游离珍珠培育效果的影响。术前处理方式分别为抑制母贝性腺发育和促进性腺发育排精产卵,珠核规格分别为5.0 mm、6.0 mm、7.0 mm和8.0 mm,手术贝休养期为1个月,育珠期为18个月。结果显示:术前处理和珠核规格对育珠贝成活率、留核率和成珠率存在显著影响(P0.05),促进性腺发育排精产卵处理的育珠贝休养期、育珠期成活率、留核率和成珠率最高(62.0%、54.0%、21.0%和48.0%),未经术前处理的对照组最低(50.0%、38.0%、11.0%和32.0%),珠核直径5.0 mm组休养期、育珠期手术贝成活率、留核率和成珠率最高(64.0%、54.0%、22.0%和45.0%),8.0mm最低(42.0%、33.0%、8.0%和22.0%)。本研究结果表明,通过手术前处理可以显著提高企鹅珍珠贝育珠贝的成活率、留核率和成珠率,企鹅珍珠贝游离珍珠培育的合适的珠核规格为5.0~6.0 mm。 相似文献
4.
企鹅珍珠贝游离有核珍珠培育技术 总被引：1，自引：0，他引：1
2007~2011年,借鉴马氏珠母贝游离有核珍珠植核方法,根据企鹅珍珠贝生理机能特性以及植核部位的组织构造特点,摸索出企鹅珍珠贝术前处理、栓口、植核施术、术后休养和育珠期管养等系统性的植核育珠技术。5年间,共植核企鹅珍珠贝245710个,植核贝经过60 d的休养,成活率为91.3%~96.0%,平均休养期成活率为94.0%;植核贝再经过16~22个月的育珠期后,成活率为90.3%~96.3%,平均育珠期成活率为94.3%;共收获游离有核珍珠69 158颗,成珠率为27.5%~33.8%,平均成珠率为30.7%,其中共收获商品珠54 825颗,商品珠率为68.5%~83.8%,平均商品珠率为79.3%。 相似文献
5.
利用马氏珠母贝4个壳色系F3培育厚层优质珍珠 总被引：1，自引：1，他引：0
为了评价红、金黄、白和黑壳色系F3育珠性状,设立两个实验,分别利用马氏珠母贝红、金黄、白和黑壳色系F3作为植核(受体)贝和小片(供体)贝进行植核育珠。实验Ⅰ:利用红、金黄、白和黑壳色系F3为插核贝和小片贝建立16个组合,另外利用以普通养殖群体为插核贝、金黄壳色系F3为小片贝建立了1个组合,共建立17个组合,育珠期为24个月;实验Ⅱ:分别利用红、金黄、白和黑壳色系F3为植核贝和小片贝建立16个组合,育珠期为18个月。结果表明,育珠期结束后实验Ⅰ和Ⅱ的4个壳色系F3平均壳高和成活率均存在显著性差异(P<0.05),实验Ⅰ和Ⅱ的黑壳色系F3具有最大的平均壳高,实验Ⅰ金黄壳色系F3具有最高的成活率,实验Ⅱ黑壳色系F3具有最高的成活率。实验Ⅰ:各组合间的留核率、商品珠率、优良珠率和育珠绩效均存在显著性差异(P<0.05),珍珠层厚度差异不显著(P>0.05);BW组具有最大的留核率、商品珠率、珠层厚度和育珠绩效值,RB组具有最大的优良珠率;实验Ⅱ:各组合的留核率、商品珠率、优良珠率、珍珠层厚度和育珠绩效均存在显著性差异(P<0.05)。黑壳色系F3作为插核贝具有较好的育珠效果,经进一步测试其育珠性能,可在珍珠生产中推广应用。 相似文献
6.
贝龄对马氏珠母贝植核贝生长、成活率和育珠性状的影响 总被引：6，自引：1，他引：5
以马氏珠母贝(Pinctada martensii)速长系F2为材料,分析了贝龄对植核贝生长、成活率和育珠性状影响。实验设2.0龄贝植核组(A)、2.0龄贝对照组(B),1.5龄贝植核组(C)和1.5龄贝对照组(D),按照常规技术进行插核手术与海区养殖,育珠期为450 d。在插核后第15、30、60、180、270和450天,比较各组的平均体质量和成活率差异;在插核后270 d和450 d,比较A和C组留核率、珍珠层厚度、优质珠率和珍珠产量的差异。结果表明,在插核后第15、30、60、180和270和450天,4个组的平均体质量和成活率均存在显著性差异(P<0.05),C和D组的成活率显著大于A和B组(P<0.05),C和D组的体质量日增长率显著大于A和B组(P<0.05)。在插核后第270天,A和C组的留核率、珍珠层厚度和珍珠产量均存在显著性差异(P<0.05),A和C组间优质珠率差异不显著(P>0.05);在插核后第450天,C组留核率、珍珠厚度、优质珠率和珍珠产量均显著大于A组(P<0.05)。结论认为,利用低龄贝进行插核育珠明显提高植核贝的留核率、成活率和珍珠层厚度,从而能够提高珍珠质量。本研究旨在为合理设计马氏珠母贝的养殖模式提供科学依据。 相似文献
7.
8.
9.
珠母贝人工培育黑珍珠的影响因素分析 总被引：4，自引：0，他引：4
采用不同术前处理方法、不同贝龄和不同珠核规格的实验条件,探讨珠母贝(Pinctada margaritifera)育珠效果的影响因素.术前处理方法包括温差促排和阴干促排,贝龄设为1.5龄、2.0龄、2.5龄和3.0龄,珠核直径设为5.5 mm、6.0mm、6.5 mm和7.0mm.经1个月的休养和21个月的育珠,结果显示,休养与育珠期间,温差促排、阴干促排和未处理组间的成活率没有显著性差异(P>0.05),但留核率、收珠率和优珠率存在显著性差异(P<0.05),其中温差促排组和未处理组分别具有最高和最低的留核率、收珠率和优珠率;4个贝龄组的成活率、留核率和收珠率存在显著性差异(P<0.05),其中1.5龄组具有最高的成活率,2龄组具有最高的留核率和收珠率,3龄组具有最低的成活率、留核率和收珠率;4个珠核规格组间的成活率、留核率和收珠率存在显著性差异(P<0.05),其中6.0 mm组和 7.0 mm组分别具有最高和最低的留核率和收珠率.研究结果说明,术前处理具有明显提高珠母贝植核贝的成活率、留核率和收珠率;珠母贝第一次植核的最适贝龄应是1.5～2龄:珠母贝第一次植核的珠核适宜规格为6.0 mm.本研究旨在为优质珍珠的培育提供理论参考. 相似文献
10.
1．1淡水有核珍珠养殖周期 圆球形有核珍珠的育珠周期根据插植珍珠核大小而定。5-6mm珠核，养殖1年即可采珠；7-8mm珠核，养殖1．5-2．0年采收，珍珠皮层厚可达0．8mm以上；9～10mm珠核一般要养殖2～3年。珍珠皮层可达1．0—1．5mm。珠核越大．珍珠皮层要求越厚，养殖周期越长。总体来说．珍珠皮层厚的有核珍珠，质量佳，价格高。 相似文献
11.
Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean 
下载免费PDF全文
下载免费PDF全文 The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna. 相似文献
12.
Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
13.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg. 相似文献
14.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
15.
Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
16.
William King V David L. Berlinsky Craig V. Sullivan 《Fish physiology and biochemistry》1995,14(6):489-500
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass. 相似文献
17.
Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide 总被引：1，自引：0，他引：1
Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response. 相似文献
18.
Sandra García‐Garrido Ismael Hachero‐Cruzado Carlos Rosas Pedro Domingues 《Aquaculture Research》2013,44(11):1741-1751
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting. 相似文献
19.
An overview of stress physiology of fish transport: changes in water quality as a function of transport duration 下载免费PDF全文
下载免费PDF全文 This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO2 and ions should be more often evaluated. Plasma Na+ and Cl‐ are very useful markers of acidosis, due to their respective exchange for H+ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters. 相似文献
20.
Are hatchery‐reared abalone naïve of predators? Comparing the behaviours of wild and hatchery‐reared northern abalone,Haliotis kamtschatkana (Jonas, 1845) 下载免费PDF全文
下载免费PDF全文 Abalone populations have declined worldwide, generating interest in enhancement using hatchery‐reared individuals. In many cases, such restoration efforts have met with limited success due to high predator‐induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone (Haliotis kamtschatkana) as a case study to determine whether hatchery‐reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery‐reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery‐reared individuals remained subdued. Anti‐predator behavioural deficits in hatchery‐reared abalone were more pronounced in 4‐year‐old individuals than in 1‐year‐old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery‐reared abalone to predators, and are likely a major cause of their elevated predator‐induced mortality when outplanted. 相似文献